Merge pull request #31112 from famiu/refactor/options/set_option_for

refactor(options): set option value for non-current context directly

14 files changed, 529 insertions, 557 deletions

diff --git a/src/nvim/api/deprecated.c b/src/nvim/api/deprecated.c
index d5eddb74de..47a49436ab 100644
--- a/src/nvim/api/deprecated.c
+++ b/src/nvim/api/deprecated.c
@@ -649,8 +649,8 @@ static Object get_option_from(void *from, OptScope scope, String name, Error *er
   OptVal value = NIL_OPTVAL;
 
   if (option_has_scope(opt_idx, scope)) {
-    value = get_option_value_for(opt_idx, scope == kOptScopeGlobal ? OPT_GLOBAL : OPT_LOCAL,
-                                 scope, from, err);
+    value = get_option_value_from(opt_idx, option_ctx_from(scope, from),
+                                  scope == kOptScopeGlobal ? OPT_GLOBAL : OPT_LOCAL);
     if (ERROR_SET(err)) {
       return (Object)OBJECT_INIT;
     }
@@ -701,7 +701,11 @@ static void set_option_to(uint64_t channel_id, void *to, OptScope scope, String
       : ((scope == kOptScopeGlobal) ? OPT_GLOBAL : OPT_LOCAL);
 
   WITH_SCRIPT_CONTEXT(channel_id, {
-    set_option_value_for(name.data, opt_idx, optval, opt_flags, scope, to, err);
+    const char *errmsg
+      = set_option_value_for(opt_idx, optval, option_ctx_from(scope, to), opt_flags);
+    if (errmsg) {
+      api_set_error(err, kErrorTypeException, "%s", errmsg);
+    }
   });
 }
 
diff --git a/src/nvim/api/options.c b/src/nvim/api/options.c
index 64f8a35d54..2bbbdbbe8c 100644
--- a/src/nvim/api/options.c
+++ b/src/nvim/api/options.c
@@ -157,8 +157,8 @@ Object nvim_get_option_value(String name, Dict(option) *opts, Error *err)
   void *from = NULL;
   char *filetype = NULL;
 
-  if (!validate_option_value_args(opts, name.data, &opt_idx, &opt_flags, &scope, &from,
-                                  &filetype, err)) {
+  if (!validate_option_value_args(opts, name.data, &opt_idx, &opt_flags, &scope, &from, &filetype,
+                                  err)) {
     return (Object)OBJECT_INIT;
   }
 
@@ -182,7 +182,7 @@ Object nvim_get_option_value(String name, Dict(option) *opts, Error *err)
     from = ftbuf;
   }
 
-  OptVal value = get_option_value_for(opt_idx, opt_flags, scope, from, err);
+  OptVal value = get_option_value_from(opt_idx, option_ctx_from(scope, from), opt_flags);
 
   if (ftbuf != NULL) {
     // restore curwin/curbuf and a few other things
@@ -257,7 +257,11 @@ void nvim_set_option_value(uint64_t channel_id, String name, Object value, Dict(
   });
 
   WITH_SCRIPT_CONTEXT(channel_id, {
-    set_option_value_for(name.data, opt_idx, optval, opt_flags, scope, to, err);
+    const char *errmsg
+      = set_option_value_for(opt_idx, optval, option_ctx_from(scope, to), opt_flags);
+    if (errmsg) {
+      api_set_error(err, kErrorTypeException, "%s", errmsg);
+    }
   });
 }
 
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index e3e69f4ff6..46e6b24c75 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -983,10 +983,10 @@ Buffer nvim_create_buf(Boolean listed, Boolean scratch, Error *err)
     buf_copy_options(buf, BCO_ENTER | BCO_NOHELP);
 
     if (scratch) {
-      set_option_direct_for(kOptBufhidden, STATIC_CSTR_AS_OPTVAL("hide"), OPT_LOCAL, 0,
-                            kOptScopeBuf, buf);
-      set_option_direct_for(kOptBuftype, STATIC_CSTR_AS_OPTVAL("nofile"), OPT_LOCAL, 0,
-                            kOptScopeBuf, buf);
+      set_option_direct_for(kOptBufhidden, STATIC_CSTR_AS_OPTVAL("hide"),
+                            option_ctx_from(kOptScopeBuf, buf), OPT_LOCAL, 0);
+      set_option_direct_for(kOptBuftype, STATIC_CSTR_AS_OPTVAL("nofile"),
+                            option_ctx_from(kOptScopeBuf, buf), OPT_LOCAL, 0);
       assert(buf->b_ml.ml_mfp->mf_fd < 0);  // ml_open() should not have opened swapfile already
       buf->b_p_swf = false;
       buf->b_p_ml = false;
diff --git a/src/nvim/autocmd.c b/src/nvim/autocmd.c
index eb7c8c2880..aab09de6b4 100644
--- a/src/nvim/autocmd.c
+++ b/src/nvim/autocmd.c
@@ -1251,56 +1251,82 @@ bool check_nomodeline(char **argp)
   return true;
 }
 
-/// Prepare for executing autocommands for (hidden) buffer `buf`.
-/// If the current buffer is not in any visible window, put it in a temporary
-/// floating window using an entry in `aucmd_win[]`.
-/// Set `curbuf` and `curwin` to match `buf`.
+/// Prepare for executing autocommands for (hidden) buffer `buf` on window `win`
+/// If the buffer of `win` is not `buf`, switch the buffer of `win` to `buf` temporarily.
 ///
-/// @param aco  structure to save values in
-/// @param buf  new curbuf
-void aucmd_prepbuf(aco_save_T *aco, buf_T *buf)
+/// @param  aco      Structure to save values in.
+/// @param  buf      New curbuf.
+/// @param  win      New curwin.
+void aucmd_prepbuf_win(aco_save_T *aco, buf_T *buf, win_T *win)
 {
-  win_T *win;
-  bool need_append = true;  // Append `aucmd_win` to the window list.
+  bool need_append = false;  // Append `aucmd_win` to the window list.
+  int auc_idx = -1;  // Index of aucmd_win[] to use. -1 if not using aucmd_win[].
 
-  // Find a window that is for the new buffer
-  if (buf == curbuf) {  // be quick when buf is curbuf
-    win = curwin;
-  } else {
-    win = NULL;
-    FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
-      if (wp->w_buffer == buf) {
-        win = wp;
-        break;
+  aco->save_curtab_handle = -1;
+  aco->save_buf_handle = -1;
+
+  if (win == NULL) {
+    // Window not provided. Find a window that is for the new buffer
+    if (buf == curbuf) {  // be quick when buf is curbuf
+      win = curwin;
+    } else {
+      win = NULL;
+      FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
+        if (wp->w_buffer == buf) {
+          win = wp;
+          break;
+        }
       }
     }
-  }
 
-  // Allocate a window when needed.
-  win_T *auc_win = NULL;
-  int auc_idx = AUCMD_WIN_COUNT;
-  if (win == NULL) {
-    for (auc_idx = 0; auc_idx < AUCMD_WIN_COUNT; auc_idx++) {
-      if (!aucmd_win[auc_idx].auc_win_used) {
-        break;
+    // Allocate a window when needed.
+    if (win == NULL) {
+      for (auc_idx = 0; auc_idx < AUCMD_WIN_COUNT; auc_idx++) {
+        if (!aucmd_win[auc_idx].auc_win_used) {
+          break;
+        }
+      }
+
+      if (auc_idx == AUCMD_WIN_COUNT) {
+        kv_push(aucmd_win_vec, ((aucmdwin_T){
+          .auc_win = NULL,
+          .auc_win_used = false,
+        }));
+      }
+
+      if (aucmd_win[auc_idx].auc_win == NULL) {
+        win_alloc_aucmd_win(auc_idx);
+      } else {
+        need_append = true;
       }
+      win = aucmd_win[auc_idx].auc_win;
+      aucmd_win[auc_idx].auc_win_used = true;
     }
+  } else {
+    tabpage_T *tp = win_find_tabpage(win);
 
-    if (auc_idx == AUCMD_WIN_COUNT) {
-      kv_push(aucmd_win_vec, ((aucmdwin_T){
-        .auc_win = NULL,
-        .auc_win_used = false,
-      }));
+    // If the window is in another tab page, switch to that tab page temporarily.
+    if (tp != curtab) {
+      aco->save_curtab_handle = curtab->handle;
+      unuse_tabpage(curtab);
+      use_tabpage(tp);
     }
+  }
 
-    if (aucmd_win[auc_idx].auc_win == NULL) {
-      win_alloc_aucmd_win(auc_idx);
-      need_append = false;
+  // If the buffer of the window is not the target buffer, switch to it temporarily.
+  if (win->w_buffer != buf) {
+    if (auc_idx == -1) {
+      // No need to store old buffer for aucmd_win[].
+      aco->save_buf_handle = win->w_buffer->handle;
+      win->w_buffer->b_nwindows--;
     }
-    auc_win = aucmd_win[auc_idx].auc_win;
-    aucmd_win[auc_idx].auc_win_used = true;
+
+    win->w_buffer = buf;
+    win->w_s = &buf->b_s;
+    buf->b_nwindows++;
   }
 
+  aco->use_aucmd_win_idx = auc_idx;
   aco->save_curwin_handle = curwin->handle;
   aco->save_prevwin_handle = prevwin == NULL ? 0 : prevwin->handle;
   aco->save_State = State;
@@ -1308,26 +1334,15 @@ void aucmd_prepbuf(aco_save_T *aco, buf_T *buf)
     aco->save_prompt_insert = curbuf->b_prompt_insert;
   }
 
-  if (win != NULL) {
-    // There is a window for "buf" in the current tab page, make it the
-    // curwin.  This is preferred, it has the least side effects (esp. if
-    // "buf" is curbuf).
-    aco->use_aucmd_win_idx = -1;
-    curwin = win;
-  } else {
-    // There is no window for "buf", use "auc_win".  To minimize the side
-    // effects, insert it in the current tab page.
-    // Anything related to a window (e.g., setting folds) may have
-    // unexpected results.
-    aco->use_aucmd_win_idx = auc_idx;
-    auc_win->w_buffer = buf;
-    auc_win->w_s = &buf->b_s;
-    buf->b_nwindows++;
-    win_init_empty(auc_win);  // set cursor and topline to safe values
+  if (auc_idx >= 0) {
+    // There is no window for "buf", use "win". To minimize the side effects, insert it in the
+    // current tab page. Anything related to a window (e.g., setting folds) may have unexpected
+    // results.
+    win_init_empty(win);  // Set cursor and topline to safe values.
 
-    // Make sure w_localdir, tp_localdir and globaldir are NULL to avoid a
-    // chdir() in win_enter_ext().
-    XFREE_CLEAR(auc_win->w_localdir);
+    // Make sure w_localdir, tp_localdir and globaldir are NULL to avoid a chdir() in
+    // win_enter_ext().
+    XFREE_CLEAR(win->w_localdir);
     aco->tp_localdir = curtab->tp_localdir;
     curtab->tp_localdir = NULL;
     aco->globaldir = globaldir;
@@ -1335,30 +1350,43 @@ void aucmd_prepbuf(aco_save_T *aco, buf_T *buf)
 
     block_autocmds();  // We don't want BufEnter/WinEnter autocommands.
     if (need_append) {
-      win_append(lastwin, auc_win, NULL);
-      pmap_put(int)(&window_handles, auc_win->handle, auc_win);
-      win_config_float(auc_win, auc_win->w_config);
+      win_append(lastwin, win, NULL);
+      pmap_put(int)(&window_handles, win->handle, win);
+      win_config_float(win, win->w_config);
     }
     // Prevent chdir() call in win_enter_ext(), through do_autochdir()
     const int save_acd = p_acd;
     p_acd = false;
-    // no redrawing and don't set the window title
+    // No redrawing and don't set the window title
     RedrawingDisabled++;
-    win_enter(auc_win, false);
+    win_enter(win, false);
     RedrawingDisabled--;
     p_acd = save_acd;
     unblock_autocmds();
-    curwin = auc_win;
   }
+
+  curwin = win;
   curbuf = buf;
   aco->new_curwin_handle = curwin->handle;
   set_bufref(&aco->new_curbuf, curbuf);
 
-  // disable the Visual area, the position may be invalid in another buffer
+  // Disable the Visual area, the position may be invalid in another buffer
   aco->save_VIsual_active = VIsual_active;
   VIsual_active = false;
 }
 
+/// Prepare for executing autocommands for (hidden) buffer `buf`.
+/// If the current buffer is not in any visible window, put it in a temporary
+/// floating window using an entry in `aucmd_win[]`.
+/// Set `curbuf` and `curwin` to match `buf`.
+///
+/// @param  aco  structure to save values in
+/// @param  buf  new curbuf
+void aucmd_prepbuf(aco_save_T *aco, buf_T *buf)
+{
+  aucmd_prepbuf_win(aco, buf, NULL);
+}
+
 /// Cleanup after executing autocommands for a (hidden) buffer.
 /// Restore the window as it was (if possible).
 ///
@@ -1447,6 +1475,19 @@ win_found:
       curwin->w_topfill = 0;
     }
   } else {
+    // Restore old buffer of new window if it was changed.
+    if (aco->save_buf_handle != -1) {
+      win_T *new_win = win_find_by_handle(aco->new_curwin_handle);
+      buf_T *new_win_buf = handle_get_buffer(aco->save_buf_handle);
+
+      if (new_win != NULL && new_win_buf != NULL) {
+        new_win->w_buffer->b_nwindows--;
+        new_win->w_buffer = new_win_buf;
+        new_win->w_s = &new_win_buf->b_s;
+        new_win_buf->b_nwindows++;
+      }
+    }
+
     // Restore curwin.  Use the window ID, a window may have been closed
     // and the memory re-used for another one.
     win_T *const save_curwin = win_find_by_handle(aco->save_curwin_handle);
@@ -1482,6 +1523,13 @@ win_found:
   if (VIsual_active) {
     check_pos(curbuf, &VIsual);
   }
+
+  // Switch back to the original tab page if it was switched.
+  if (aco->save_curtab_handle != -1) {
+    tabpage_T *save_curtab = handle_get_tabpage(aco->save_curtab_handle);
+    unuse_tabpage(curtab);
+    use_tabpage(save_curtab);
+  }
 }
 
 /// Execute autocommands for "event" and file name "fname".
diff --git a/src/nvim/autocmd_defs.h b/src/nvim/autocmd_defs.h
index cba947e85f..777ee7b87a 100644
--- a/src/nvim/autocmd_defs.h
+++ b/src/nvim/autocmd_defs.h
@@ -14,16 +14,18 @@
 /// Struct to save values in before executing autocommands for a buffer that is
 /// not the current buffer.
 typedef struct {
-  int use_aucmd_win_idx;          ///< index in aucmd_win[] if >= 0
-  handle_T save_curwin_handle;    ///< ID of saved curwin
-  handle_T new_curwin_handle;     ///< ID of new curwin
-  handle_T save_prevwin_handle;   ///< ID of saved prevwin
-  bufref_T new_curbuf;            ///< new curbuf
-  char *tp_localdir;              ///< saved value of tp_localdir
-  char *globaldir;                ///< saved value of globaldir
-  bool save_VIsual_active;        ///< saved VIsual_active
-  int save_State;                 ///< saved State
-  int save_prompt_insert;         ///< saved b_prompt_insert
+  int use_aucmd_win_idx;             ///< index in aucmd_win[] if >= 0
+  handle_T save_curwin_handle;       ///< ID of saved curwin
+  handle_T save_curtab_handle;       ///< ID of saved curtab. -1 if not switched.
+  handle_T new_curwin_handle;        ///< ID of new curwin
+  handle_T save_buf_handle;          ///< ID of saved buffer of new curwin. -1 if not switched.
+  handle_T save_prevwin_handle;      ///< ID of saved prevwin
+  bufref_T new_curbuf;               ///< new curbuf
+  char *tp_localdir;                 ///< saved value of tp_localdir
+  char *globaldir;                   ///< saved value of globaldir
+  bool save_VIsual_active;           ///< saved VIsual_active
+  int save_State;                    ///< saved State
+  int save_prompt_insert;            ///< saved b_prompt_insert
 } aco_save_T;
 
 typedef struct {
diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index bd98a31a71..ebeb9ba088 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -1391,8 +1391,8 @@ void diff_win_options(win_T *wp, bool addbuf)
     }
     wp->w_p_fdm_save = xstrdup(wp->w_p_fdm);
   }
-  set_option_direct_for(kOptFoldmethod, STATIC_CSTR_AS_OPTVAL("diff"), OPT_LOCAL, 0,
-                        kOptScopeWin, wp);
+  set_option_direct_for(kOptFoldmethod, STATIC_CSTR_AS_OPTVAL("diff"),
+                        option_ctx_from(kOptScopeWin, wp), OPT_LOCAL, 0);
 
   if (!wp->w_p_diff) {
     wp->w_p_fen_save = wp->w_p_fen;
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index 6f9f0f07c9..ceb3a074b4 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -5294,7 +5294,7 @@ static char *findfunc_find_file(char *findarg, size_t findarg_len, int count)
 /// Returns NULL on success and an error message on failure.
 const char *did_set_findfunc(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   int retval;
 
   if (args->os_flags & OPT_LOCAL) {
diff --git a/src/nvim/insexpand.c b/src/nvim/insexpand.c
index 9b77644085..053d97fd64 100644
--- a/src/nvim/insexpand.c
+++ b/src/nvim/insexpand.c
@@ -2401,7 +2401,7 @@ static void copy_global_to_buflocal_cb(Callback *globcb, Callback *bufcb)
 /// lambda expression.
 const char *did_set_completefunc(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   if (option_set_callback_func(buf->b_p_cfu, &cfu_cb) == FAIL) {
     return e_invarg;
   }
@@ -2422,7 +2422,7 @@ void set_buflocal_cfu_callback(buf_T *buf)
 /// lambda expression.
 const char *did_set_omnifunc(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   if (option_set_callback_func(buf->b_p_ofu, &ofu_cb) == FAIL) {
     return e_invarg;
   }
@@ -2443,7 +2443,7 @@ void set_buflocal_ofu_callback(buf_T *buf)
 /// lambda expression.
 const char *did_set_thesaurusfunc(optset_T *args FUNC_ATTR_UNUSED)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   int retval;
 
   if (args->os_flags & OPT_LOCAL) {
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 551ea0be20..2b102fe1bb 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -1324,7 +1324,8 @@ static void do_one_set_option(int opt_flags, char **argp, bool *did_show, char *
     return;
   }
 
-  *errmsg = set_option(opt_idx, newval, opt_flags, 0, false, op == OP_NONE, errbuf, errbuflen);
+  *errmsg = set_option_for(opt_idx, newval, option_ctx(), opt_flags, 0, false,
+                           op == OP_NONE, errbuf, errbuflen);
 }
 
 /// Parse 'arg' for option settings.
@@ -1844,7 +1845,7 @@ void set_option_sctx(OptIndex opt_idx, int opt_flags, sctx_T script_ctx)
 
 /// Apply the OptionSet autocommand.
 static void apply_optionset_autocmd(OptIndex opt_idx, int opt_flags, OptVal oldval, OptVal oldval_g,
-                                    OptVal oldval_l, OptVal newval, const char *errmsg)
+                                    OptVal oldval_l, OptVal newval, OptCtx ctx, const char *errmsg)
 {
   // Don't do this while starting up, failure or recursively.
   if (starting || errmsg != NULL || *get_vim_var_str(VV_OPTION_TYPE) != NUL) {
@@ -1878,14 +1879,18 @@ static void apply_optionset_autocmd(OptIndex opt_idx, int opt_flags, OptVal oldv
     set_vim_var_string(VV_OPTION_COMMAND, "modeline", -1);
     set_vim_var_tv(VV_OPTION_OLDLOCAL, &oldval_tv);
   }
-  apply_autocmds(EVENT_OPTIONSET, options[opt_idx].fullname, NULL, false, NULL);
+
+  WITH_AUCMD_CONTEXT(ctx, {
+    apply_autocmds(EVENT_OPTIONSET, options[opt_idx].fullname, NULL, false, NULL);
+  });
+
   reset_v_option_vars();
 }
 
 /// Process the updated 'arabic' option value.
 static const char *did_set_arabic(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   const char *errmsg = NULL;
 
   if (win->w_p_arab) {
@@ -1954,7 +1959,7 @@ static const char *did_set_autochdir(optset_T *args FUNC_ATTR_UNUSED)
 /// Process the updated 'binary' option value.
 static const char *did_set_binary(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
 
   // when 'bin' is set also set some other options
   set_options_bin((int)args->os_oldval.boolean, buf->b_p_bin, args->os_flags);
@@ -1966,7 +1971,7 @@ static const char *did_set_binary(optset_T *args)
 /// Process the updated 'buflisted' option value.
 static const char *did_set_buflisted(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
 
   // when 'buflisted' changes, trigger autocommands
   if (args->os_oldval.boolean != buf->b_p_bl) {
@@ -2000,7 +2005,7 @@ static const char *did_set_cmdheight(optset_T *args)
 /// Process the updated 'diff' option value.
 static const char *did_set_diff(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   // May add or remove the buffer from the list of diff buffers.
   diff_buf_adjust(win);
   if (foldmethodIsDiff(win)) {
@@ -2021,7 +2026,7 @@ static const char *did_set_eof_eol_fixeol_bomb(optset_T *args FUNC_ATTR_UNUSED)
 /// Process the updated 'equalalways' option value.
 static const char *did_set_equalalways(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   if (p_ea && !args->os_oldval.boolean) {
     win_equal(win, false, 0);
   }
@@ -2039,7 +2044,7 @@ static const char *did_set_foldlevel(optset_T *args FUNC_ATTR_UNUSED)
 /// Process the new 'foldminlines' option value.
 static const char *did_set_foldminlines(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   foldUpdateAll(win);
   return NULL;
 }
@@ -2047,7 +2052,7 @@ static const char *did_set_foldminlines(optset_T *args)
 /// Process the new 'foldnestmax' option value.
 static const char *did_set_foldnestmax(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   if (foldmethodIsSyntax(win) || foldmethodIsIndent(win)) {
     foldUpdateAll(win);
   }
@@ -2176,7 +2181,7 @@ static const char *did_set_lines_or_columns(optset_T *args)
 /// Process the updated 'lisp' option value.
 static const char *did_set_lisp(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   // When 'lisp' option changes include/exclude '-' in keyword characters.
   buf_init_chartab(buf, false);          // ignore errors
   return NULL;
@@ -2194,7 +2199,7 @@ static const char *did_set_modifiable(optset_T *args FUNC_ATTR_UNUSED)
 /// Process the updated 'modified' option value.
 static const char *did_set_modified(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   if (!args->os_newval.boolean) {
     save_file_ff(buf);  // Buffer is unchanged
   }
@@ -2206,7 +2211,7 @@ static const char *did_set_modified(optset_T *args)
 /// Process the updated 'number' or 'relativenumber' option value.
 static const char *did_set_number_relativenumber(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   if (*win->w_p_stc != NUL) {
     // When 'relativenumber'/'number' is changed and 'statuscolumn' is set, reset width.
     win->w_nrwidth_line_count = 0;
@@ -2218,7 +2223,7 @@ static const char *did_set_number_relativenumber(optset_T *args)
 /// Process the new 'numberwidth' option value.
 static const char *did_set_numberwidth(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   win->w_nrwidth_line_count = 0;  // trigger a redraw
 
   return NULL;
@@ -2356,7 +2361,7 @@ static const char *did_set_paste(optset_T *args FUNC_ATTR_UNUSED)
 /// Process the updated 'previewwindow' option value.
 static const char *did_set_previewwindow(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
 
   if (!win->w_p_pvw) {
     return NULL;
@@ -2388,7 +2393,7 @@ static const char *did_set_pumblend(optset_T *args FUNC_ATTR_UNUSED)
 /// Process the updated 'readonly' option value.
 static const char *did_set_readonly(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
 
   // when 'readonly' is reset globally, also reset readonlymode
   if (!buf->b_p_ro && (args->os_flags & OPT_LOCAL) == 0) {
@@ -2408,7 +2413,7 @@ static const char *did_set_readonly(optset_T *args)
 /// Process the new 'scrollback' option value.
 static const char *did_set_scrollback(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   OptInt old_value = args->os_oldval.number;
   OptInt value = args->os_newval.number;
 
@@ -2422,7 +2427,7 @@ static const char *did_set_scrollback(optset_T *args)
 /// Process the updated 'scrollbind' option value.
 static const char *did_set_scrollbind(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
 
   // when 'scrollbind' is set: snapshot the current position to avoid a jump
   // at the end of normal_cmd()
@@ -2459,8 +2464,8 @@ static const char *did_set_shellslash(optset_T *args FUNC_ATTR_UNUSED)
 /// Process the new 'shiftwidth' or the 'tabstop' option value.
 static const char *did_set_shiftwidth_tabstop(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
-  win_T *win = (win_T *)args->os_win;
+  buf_T *buf = args->os_ctx.buf;
+  win_T *win = args->os_ctx.win;
   OptInt *pp = (OptInt *)args->os_varp;
 
   if (foldmethodIsIndent(win)) {
@@ -2486,7 +2491,7 @@ static const char *did_set_showtabline(optset_T *args FUNC_ATTR_UNUSED)
 /// Process the updated 'smoothscroll' option value.
 static const char *did_set_smoothscroll(optset_T *args FUNC_ATTR_UNUSED)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   if (!win->w_p_sms) {
     win->w_skipcol = 0;
   }
@@ -2497,7 +2502,7 @@ static const char *did_set_smoothscroll(optset_T *args FUNC_ATTR_UNUSED)
 /// Process the updated 'spell' option value.
 static const char *did_set_spell(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   if (win->w_p_spell) {
     return parse_spelllang(win);
   }
@@ -2508,7 +2513,7 @@ static const char *did_set_spell(optset_T *args)
 /// Process the updated 'swapfile' option value.
 static const char *did_set_swapfile(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   // when 'swf' is set, create swapfile, when reset remove swapfile
   if (buf->b_p_swf && p_uc) {
     ml_open_file(buf);                     // create the swap file
@@ -2553,7 +2558,7 @@ static const char *did_set_titlelen(optset_T *args)
 /// Process the updated 'undofile' option value.
 static const char *did_set_undofile(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
 
   // Only take action when the option was set.
   if (!buf->b_p_udf && !p_udf) {
@@ -2604,7 +2609,7 @@ const char *did_set_buflocal_undolevels(buf_T *buf, OptInt value, OptInt old_val
 /// Process the new 'undolevels' option value.
 static const char *did_set_undolevels(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   OptInt *pp = (OptInt *)args->os_varp;
 
   if (pp == &p_ul) {                  // global 'undolevels'
@@ -2645,7 +2650,7 @@ static const char *did_set_wildchar(optset_T *args)
 /// Process the new 'winblend' option value.
 static const char *did_set_winblend(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   OptInt old_value = args->os_oldval.number;
   OptInt value = args->os_newval.number;
 
@@ -2694,7 +2699,7 @@ static const char *did_set_winwidth(optset_T *args)
 /// Process the updated 'wrap' option value.
 static const char *did_set_wrap(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   // Set w_leftcol or w_skipcol to zero.
   if (win->w_p_wrap) {
     win->w_leftcol = 0;
@@ -3143,12 +3148,6 @@ static OptValType option_get_type(const OptIndex opt_idx)
 OptVal optval_from_varp(OptIndex opt_idx, void *varp)
   FUNC_ATTR_NONNULL_ARG(2)
 {
-  // Special case: 'modified' is b_changed, but we also want to consider it set when 'ff' or 'fenc'
-  // changed.
-  if ((int *)varp == &curbuf->b_changed) {
-    return BOOLEAN_OPTVAL(curbufIsChanged());
-  }
-
   if (option_is_multitype(opt_idx)) {
     // Multitype options are stored as OptVal.
     return *(OptVal *)varp;
@@ -3381,21 +3380,37 @@ uint32_t get_option_flags(OptIndex opt_idx)
 /// Gets the value for an option.
 ///
 /// @param  opt_idx    Option index in options[] table.
+/// @param  ctx        Context to get the option value from.
 /// @param  opt_flags  Option flags (can be OPT_LOCAL, OPT_GLOBAL or a combination).
 ///
 /// @return [allocated] Option value. Returns NIL_OPTVAL for invalid option index.
-OptVal get_option_value(OptIndex opt_idx, int opt_flags)
+OptVal get_option_value_from(OptIndex opt_idx, OptCtx ctx, int opt_flags)
 {
   if (opt_idx == kOptInvalid) {  // option not in the options[] table.
     return NIL_OPTVAL;
   }
 
-  vimoption_T *opt = &options[opt_idx];
-  void *varp = get_varp_scope(opt, opt_flags);
+  // Special case: 'modified' is b_changed, but we also want to consider it set when 'ff' or 'fenc'
+  // changed.
+  if (opt_idx == kOptModified) {
+    return BOOLEAN_OPTVAL(bufIsChanged(ctx.buf));
+  }
 
+  void * const varp = get_varp_scope_from(&options[opt_idx], opt_flags, ctx);
   return optval_copy(optval_from_varp(opt_idx, varp));
 }
 
+/// Gets the value for an option in the current context.
+///
+/// @param  opt_idx  Option index in options[] table.
+/// @param  opt_flags  Option flags (can be OPT_LOCAL, OPT_GLOBAL or a combination).
+///
+/// @return [allocated] Option value. Returns NIL_OPTVAL for invalid option index.
+OptVal get_option_value(OptIndex opt_idx, int opt_flags)
+{
+  return get_option_value_from(opt_idx, option_ctx(), opt_flags);
+}
+
 /// Return information for option at 'opt_idx'
 vimoption_T *get_option(OptIndex opt_idx)
 {
@@ -3464,6 +3479,8 @@ static bool is_option_local_value_unset(OptIndex opt_idx)
 /// @param       opt_idx         Index in options[] table. Must not be kOptInvalid.
 /// @param[in]   varp            Option variable pointer, cannot be NULL.
 /// @param       old_value       Old option value.
+/// @param       new_value       New option value.
+/// @param       ctx             Context in which the option is set.
 /// @param       opt_flags       Option flags (can be OPT_LOCAL, OPT_GLOBAL or a combination).
 /// @param       set_sid         Script ID. Special values:
 ///                                0: Use current script ID.
@@ -3475,8 +3492,9 @@ static bool is_option_local_value_unset(OptIndex opt_idx)
 ///
 /// @return  NULL on success, an untranslated error message on error.
 static const char *did_set_option(OptIndex opt_idx, void *varp, OptVal old_value, OptVal new_value,
-                                  int opt_flags, scid_T set_sid, const bool direct,
-                                  const bool value_replaced, char *errbuf, size_t errbuflen)
+                                  OptCtx ctx, int opt_flags, scid_T set_sid, const bool direct,
+                                  const bool value_replaced, char *errbuf,  // NOLINT(readability-non-const-parameter)
+                                  size_t errbuflen)
 {
   vimoption_T *opt = &options[opt_idx];
   const char *errmsg = NULL;
@@ -3495,8 +3513,7 @@ static const char *did_set_option(OptIndex opt_idx, void *varp, OptVal old_value
     .os_restore_chartab = false,
     .os_errbuf = errbuf,
     .os_errbuflen = errbuflen,
-    .os_buf = curbuf,
-    .os_win = curwin
+    .os_ctx = ctx,
   };
 
   if (direct) {
@@ -3533,7 +3550,7 @@ static const char *did_set_option(OptIndex opt_idx, void *varp, OptVal old_value
     set_option_varp(opt_idx, varp, old_value, true);
     // When resetting some values, need to act on it.
     if (restore_chartab) {
-      buf_init_chartab(curbuf, true);
+      buf_init_chartab(ctx.buf, true);
     }
 
     return errmsg;
@@ -3564,12 +3581,12 @@ static const char *did_set_option(OptIndex opt_idx, void *varp, OptVal old_value
     if (option_is_global_local(opt_idx)) {
       // Global option with local value set to use global value.
       // Free the local value and clear it.
-      void *varp_local = get_varp_scope(opt, OPT_LOCAL);
+      void *varp_local = get_varp_scope_from(opt, OPT_LOCAL, ctx);
       OptVal local_unset_value = get_option_unset_value(opt_idx);
       set_option_varp(opt_idx, varp_local, optval_copy(local_unset_value), true);
     } else {
       // May set global value for local option.
-      void *varp_global = get_varp_scope(opt, OPT_GLOBAL);
+      void *varp_global = get_varp_scope_from(opt, OPT_GLOBAL, ctx);
       set_option_varp(opt_idx, varp_global, optval_copy(new_value), true);
     }
   }
@@ -3580,17 +3597,23 @@ static const char *did_set_option(OptIndex opt_idx, void *varp, OptVal old_value
   }
 
   // Trigger the autocommand only after setting the flags.
-  if (varp == &curbuf->b_p_syn) {
-    do_syntax_autocmd(curbuf, value_changed);
-  } else if (varp == &curbuf->b_p_ft) {
+  if (varp == &ctx.buf->b_p_syn) {
+    WITH_AUCMD_CONTEXT(ctx, {
+      do_syntax_autocmd(ctx.buf, value_changed);
+    });
+  } else if (varp == &ctx.buf->b_p_ft) {
     // 'filetype' is set, trigger the FileType autocommand
     // Skip this when called from a modeline
     // Force autocmd when the filetype was changed
     if (!(opt_flags & OPT_MODELINE) || value_changed) {
-      do_filetype_autocmd(curbuf, value_changed);
+      WITH_AUCMD_CONTEXT(ctx, {
+        do_filetype_autocmd(ctx.buf, value_changed);
+      });
     }
-  } else if (varp == &curwin->w_s->b_p_spl) {
-    do_spelllang_source(curwin);
+  } else if (varp == &ctx.win->w_s->b_p_spl) {
+    WITH_AUCMD_CONTEXT(ctx, {
+      do_spelllang_source(ctx.win);
+    });
   }
 
   // In case 'ruler' or 'showcmd' or 'columns' or 'ls' changed.
@@ -3598,25 +3621,25 @@ static const char *did_set_option(OptIndex opt_idx, void *varp, OptVal old_value
 
   if (varp == &p_mouse) {
     setmouse();  // in case 'mouse' changed
-  } else if ((varp == &p_flp || varp == &(curbuf->b_p_flp)) && curwin->w_briopt_list) {
+  } else if ((varp == &p_flp || varp == &(ctx.buf->b_p_flp)) && ctx.win->w_briopt_list) {
     // Changing Formatlistpattern when briopt includes the list setting:
     // redraw
     redraw_all_later(UPD_NOT_VALID);
-  } else if (varp == &p_wbr || varp == &(curwin->w_p_wbr)) {
+  } else if (varp == &p_wbr || varp == &(ctx.win->w_p_wbr)) {
     // add / remove window bars for 'winbar'
     set_winbar(true);
   }
 
-  if (curwin->w_curswant != MAXCOL
+  if (ctx.win->w_curswant != MAXCOL
       && (opt->flags & (kOptFlagCurswant | kOptFlagRedrAll)) != 0
       && (opt->flags & kOptFlagHLOnly) == 0) {
-    curwin->w_set_curswant = true;
+    ctx.win->w_set_curswant = true;
   }
 
-  check_redraw(opt->flags);
+  check_redraw_for(ctx.buf, ctx.win, opt->flags);
 
   if (errmsg == NULL) {
-    uint32_t *p = insecure_flag(curwin, opt_idx, opt_flags);
+    uint32_t *p = insecure_flag(ctx.win, opt_idx, opt_flags);
     opt->flags |= kOptFlagWasSet;
 
     // When an option is set in the sandbox, from a modeline or in secure mode set the kOptFlagInsecure
@@ -3676,6 +3699,7 @@ static const char *validate_option_value(const OptIndex opt_idx, OptVal *newval,
 ///
 /// @param       opt_idx         Index in options[] table. Must not be kOptInvalid.
 /// @param       value           New option value. Might get freed.
+/// @param       ctx             Context in which the option is set.
 /// @param       opt_flags       Option flags (can be OPT_LOCAL, OPT_GLOBAL or a combination).
 /// @param       set_sid         Script ID. Special values:
 ///                                0: Use current script ID.
@@ -3686,9 +3710,9 @@ static const char *validate_option_value(const OptIndex opt_idx, OptVal *newval,
 /// @param       errbuflen       Length of error buffer.
 ///
 /// @return  NULL on success, an untranslated error message on error.
-static const char *set_option(const OptIndex opt_idx, OptVal value, int opt_flags, scid_T set_sid,
-                              const bool direct, const bool value_replaced, char *errbuf,
-                              size_t errbuflen)
+static const char *set_option_for(OptIndex opt_idx, OptVal value, OptCtx ctx, int opt_flags,
+                                  scid_T set_sid, const bool direct, const bool value_replaced,
+                                  char *errbuf, size_t errbuflen)
 {
   assert(opt_idx != kOptInvalid);
 
@@ -3713,10 +3737,11 @@ static const char *set_option(const OptIndex opt_idx, OptVal value, int opt_flag
 
   // When using ":set opt=val" for a global option with a local value the local value will be reset,
   // use the global value in that case.
-  void *varp
-    = scope_both && option_is_global_local(opt_idx) ? opt->var : get_varp_scope(opt, opt_flags);
-  void *varp_local = get_varp_scope(opt, OPT_LOCAL);
-  void *varp_global = get_varp_scope(opt, OPT_GLOBAL);
+  void *varp = scope_both && option_is_global_local(opt_idx)
+               ? opt->var
+               : get_varp_scope_from(opt, opt_flags, ctx);
+  void *varp_local = get_varp_scope_from(opt, OPT_LOCAL, ctx);
+  void *varp_global = get_varp_scope_from(opt, OPT_GLOBAL, ctx);
 
   OptVal old_value = optval_from_varp(opt_idx, varp);
   OptVal old_global_value = optval_from_varp(opt_idx, varp_global);
@@ -3729,7 +3754,7 @@ static const char *set_option(const OptIndex opt_idx, OptVal value, int opt_flag
   // unset. In every other case, it is the same as old_value.
   // This value is used instead of old_value when triggering the OptionSet autocommand.
   OptVal used_old_value = (scope_local && is_opt_local_unset)
-                          ? optval_from_varp(opt_idx, get_varp(opt))
+                          ? optval_from_varp(opt_idx, get_varp_from(opt, ctx))
                           : old_value;
 
   // Save the old values and the new value in case they get changed.
@@ -3739,7 +3764,7 @@ static const char *set_option(const OptIndex opt_idx, OptVal value, int opt_flag
   // New value (and varp) may become invalid if the buffer is closed by autocommands.
   OptVal saved_new_value = optval_copy(value);
 
-  uint32_t *p = insecure_flag(curwin, opt_idx, opt_flags);
+  uint32_t *p = insecure_flag(ctx.win, opt_idx, opt_flags);
   const int secure_saved = secure;
 
   // When an option is set in the sandbox, from a modeline or in secure mode, then deal with side
@@ -3752,7 +3777,7 @@ static const char *set_option(const OptIndex opt_idx, OptVal value, int opt_flag
   // Set option through its variable pointer.
   set_option_varp(opt_idx, varp, value, false);
   // Process any side effects.
-  errmsg = did_set_option(opt_idx, varp, old_value, value, opt_flags, set_sid, direct,
+  errmsg = did_set_option(opt_idx, varp, old_value, value, ctx, opt_flags, set_sid, direct,
                           value_replaced, errbuf, errbuflen);
 
   secure = secure_saved;
@@ -3760,7 +3785,7 @@ static const char *set_option(const OptIndex opt_idx, OptVal value, int opt_flag
   if (errmsg == NULL && !direct) {
     if (!starting) {
       apply_optionset_autocmd(opt_idx, opt_flags, saved_used_value, saved_old_global_value,
-                              saved_old_local_value, saved_new_value, errmsg);
+                              saved_old_local_value, saved_new_value, ctx, errmsg);
     }
     if (opt->flags & kOptFlagUIOption) {
       ui_call_option_set(cstr_as_string(opt->fullname), optval_as_object(saved_new_value));
@@ -3780,11 +3805,13 @@ static const char *set_option(const OptIndex opt_idx, OptVal value, int opt_flag
 ///
 /// @param  opt_idx    Option index in options[] table.
 /// @param  value      Option value.
+/// @param  ctx        Context in which the option is set.
 /// @param  opt_flags  Option flags (can be OPT_LOCAL, OPT_GLOBAL or a combination).
 /// @param  set_sid    Script ID. Special values:
 ///                      0: Use current script ID.
 ///                      SID_NONE: Don't set script ID.
-void set_option_direct(OptIndex opt_idx, OptVal value, int opt_flags, scid_T set_sid)
+void set_option_direct_for(OptIndex opt_idx, OptVal value, OptCtx ctx, int opt_flags,
+                           scid_T set_sid)
 {
   static char errbuf[IOSIZE];
 
@@ -3792,57 +3819,35 @@ void set_option_direct(OptIndex opt_idx, OptVal value, int opt_flags, scid_T set
     return;
   }
 
-  const char *errmsg = set_option(opt_idx, optval_copy(value), opt_flags, set_sid, true, true,
-                                  errbuf, sizeof(errbuf));
+  const char *errmsg = set_option_for(opt_idx, optval_copy(value), ctx, opt_flags, set_sid, true,
+                                      true, errbuf, sizeof(errbuf));
   assert(errmsg == NULL);
   (void)errmsg;  // ignore unused warning
 }
 
-/// Set option value directly for buffer / window, without processing any side effects.
+/// Set option value for current context directly, without processing any side effects.
 ///
-/// @param      opt_idx    Option index in options[] table.
-/// @param      value      Option value.
-/// @param      opt_flags  Option flags (can be OPT_LOCAL, OPT_GLOBAL or a combination).
-/// @param      set_sid    Script ID. Special values:
-///                          0: Use current script ID.
-///                          SID_NONE: Don't set script ID.
-/// @param      scope      Option scope. See OptScope in option.h.
-/// @param[in]  from       Target buffer/window.
-void set_option_direct_for(OptIndex opt_idx, OptVal value, int opt_flags, scid_T set_sid,
-                           OptScope scope, void *const from)
-{
-  buf_T *save_curbuf = curbuf;
-  win_T *save_curwin = curwin;
-
-  // Don't use switch_option_context(), as that calls aucmd_prepbuf(), which may have unintended
-  // side-effects when setting an option directly. Just change the values of curbuf and curwin if
-  // needed, no need to properly switch the window / buffer.
-  switch (scope) {
-  case kOptScopeGlobal:
-    break;
-  case kOptScopeWin:
-    curwin = (win_T *)from;
-    curbuf = curwin->w_buffer;
-    break;
-  case kOptScopeBuf:
-    curbuf = (buf_T *)from;
-    break;
-  }
-
-  set_option_direct(opt_idx, value, opt_flags, set_sid);
-
-  curwin = save_curwin;
-  curbuf = save_curbuf;
+/// @param  opt_idx    Option index in options[] table.
+/// @param  value      Option value.
+/// @param  ctx        Context in which the option is set.
+/// @param  opt_flags  Option flags (can be OPT_LOCAL, OPT_GLOBAL or a combination).
+/// @param  set_sid    Script ID. Special values:
+///                      0: Use current script ID.
+///                      SID_NONE: Don't set script ID.
+void set_option_direct(OptIndex opt_idx, OptVal value, int opt_flags, scid_T set_sid)
+{
+  set_option_direct_for(opt_idx, value, option_ctx(), opt_flags, set_sid);
 }
 
 /// Set the value of an option.
 ///
 /// @param      opt_idx    Index in options[] table. Must not be kOptInvalid.
 /// @param[in]  value      Option value. If NIL_OPTVAL, the option value is cleared.
+/// @param      ctx        Context to set option for.
 /// @param[in]  opt_flags  Flags: OPT_LOCAL, OPT_GLOBAL, or 0 (both).
 ///
 /// @return  NULL on success, an untranslated error message on error.
-const char *set_option_value(const OptIndex opt_idx, const OptVal value, int opt_flags)
+const char *set_option_value_for(OptIndex opt_idx, OptVal value, OptCtx ctx, int opt_flags)
 {
   assert(opt_idx != kOptInvalid);
 
@@ -3854,7 +3859,21 @@ const char *set_option_value(const OptIndex opt_idx, const OptVal value, int opt
     return _(e_sandbox);
   }
 
-  return set_option(opt_idx, optval_copy(value), opt_flags, 0, false, true, errbuf, sizeof(errbuf));
+  return set_option_for(opt_idx, optval_copy(value), ctx, opt_flags, 0, false, true, errbuf,
+                        sizeof(errbuf));
+}
+
+/// Set the value of an option for current context.
+///
+/// @param      opt_idx    Index in options[] table. Must not be kOptInvalid.
+/// @param[in]  value      Option value. If NIL_OPTVAL, the option value is cleared.
+/// @param      ctx        Context to set option for.
+/// @param[in]  opt_flags  Flags: OPT_LOCAL, OPT_GLOBAL, or 0 (both).
+///
+/// @return  NULL on success, an untranslated error message on error.
+const char *set_option_value(OptIndex opt_idx, OptVal value, int opt_flags)
+{
+  return set_option_value_for(opt_idx, value, option_ctx(), opt_flags);
 }
 
 /// Unset the local value of a global-local option.
@@ -3910,135 +3929,6 @@ void set_option_value_give_err(const OptIndex opt_idx, OptVal value, int opt_fla
   }
 }
 
-/// Switch current context to get/set option value for window/buffer.
-///
-/// @param[out]  ctx        Current context. switchwin_T for window and aco_save_T for buffer.
-/// @param       scope      Option scope. See OptScope in option.h.
-/// @param[in]   from       Target buffer/window.
-/// @param[out]  err        Error message, if any.
-///
-/// @return  true if context was switched, false otherwise.
-static bool switch_option_context(void *const ctx, OptScope scope, void *const from, Error *err)
-{
-  switch (scope) {
-  case kOptScopeGlobal:
-    return false;
-  case kOptScopeWin: {
-    win_T *const win = (win_T *)from;
-    switchwin_T *const switchwin = (switchwin_T *)ctx;
-
-    if (win == curwin) {
-      return false;
-    }
-
-    if (switch_win_noblock(switchwin, win, win_find_tabpage(win), true)
-        == FAIL) {
-      restore_win_noblock(switchwin, true);
-
-      if (ERROR_SET(err)) {
-        return false;
-      }
-      api_set_error(err, kErrorTypeException, "Problem while switching windows");
-      return false;
-    }
-    return true;
-  }
-  case kOptScopeBuf: {
-    buf_T *const buf = (buf_T *)from;
-    aco_save_T *const aco = (aco_save_T *)ctx;
-
-    if (buf == curbuf) {
-      return false;
-    }
-    aucmd_prepbuf(aco, buf);
-    return true;
-  }
-  }
-  UNREACHABLE;
-}
-
-/// Restore context after getting/setting option for window/buffer. See switch_option_context() for
-/// params.
-static void restore_option_context(void *const ctx, OptScope scope)
-{
-  switch (scope) {
-  case kOptScopeGlobal:
-    break;
-  case kOptScopeWin:
-    restore_win_noblock((switchwin_T *)ctx, true);
-    break;
-  case kOptScopeBuf:
-    aucmd_restbuf((aco_save_T *)ctx);
-    break;
-  }
-}
-
-/// Get option value for buffer / window.
-///
-/// @param       opt_idx    Option index in options[] table.
-/// @param[out]  flagsp     Set to the option flags (see OptFlags) (if not NULL).
-/// @param[in]   scope      Option scope (can be OPT_LOCAL, OPT_GLOBAL or a combination).
-/// @param[out]  hidden     Whether option is hidden.
-/// @param       scope      Option scope. See OptScope in option.h.
-/// @param[in]   from       Target buffer/window.
-/// @param[out]  err        Error message, if any.
-///
-/// @return  Option value. Must be freed by caller.
-OptVal get_option_value_for(OptIndex opt_idx, int opt_flags, const OptScope scope, void *const from,
-                            Error *err)
-{
-  switchwin_T switchwin;
-  aco_save_T aco;
-  void *ctx = scope == kOptScopeWin ? (void *)&switchwin
-                                    : (scope == kOptScopeBuf ? (void *)&aco : NULL);
-
-  bool switched = switch_option_context(ctx, scope, from, err);
-  if (ERROR_SET(err)) {
-    return NIL_OPTVAL;
-  }
-
-  OptVal retv = get_option_value(opt_idx, opt_flags);
-
-  if (switched) {
-    restore_option_context(ctx, scope);
-  }
-
-  return retv;
-}
-
-/// Set option value for buffer / window.
-///
-/// @param       name        Option name.
-/// @param       opt_idx     Option index in options[] table.
-/// @param[in]   value       Option value.
-/// @param[in]   opt_flags   Flags: OPT_LOCAL, OPT_GLOBAL, or 0 (both).
-/// @param       scope       Option scope. See OptScope in option.h.
-/// @param[in]   from        Target buffer/window.
-/// @param[out]  err         Error message, if any.
-void set_option_value_for(const char *name, OptIndex opt_idx, OptVal value, const int opt_flags,
-                          const OptScope scope, void *const from, Error *err)
-  FUNC_ATTR_NONNULL_ARG(1)
-{
-  switchwin_T switchwin;
-  aco_save_T aco;
-  void *ctx = scope == kOptScopeWin ? (void *)&switchwin
-                                    : (scope == kOptScopeBuf ? (void *)&aco : NULL);
-
-  bool switched = switch_option_context(ctx, scope, from, err);
-  if (ERROR_SET(err)) {
-    return;
-  }
-
-  const char *const errmsg = set_option_value_handle_tty(name, opt_idx, value, opt_flags);
-  if (errmsg) {
-    api_set_error(err, kErrorTypeException, "%s", errmsg);
-  }
-
-  if (switched) {
-    restore_option_context(ctx, scope);
-  }
-}
-
 /// if 'all' == false: show changed options
 /// if 'all' == true: show all normal options
 ///
@@ -4454,13 +4344,13 @@ static int put_set(FILE *fd, char *cmd, OptIndex opt_idx, void *varp)
   return OK;
 }
 
-void *get_varp_scope_from(vimoption_T *p, int opt_flags, buf_T *buf, win_T *win)
+void *get_varp_scope_from(vimoption_T *p, int opt_flags, OptCtx ctx)
 {
   OptIndex opt_idx = get_opt_idx(p);
 
   if ((opt_flags & OPT_GLOBAL) && !option_is_global_only(opt_idx)) {
     if (option_is_window_local(opt_idx)) {
-      return GLOBAL_WO(get_varp_from(p, buf, win));
+      return GLOBAL_WO(get_varp_from(p, ctx));
     }
     return p->var;
   }
@@ -4468,88 +4358,73 @@ void *get_varp_scope_from(vimoption_T *p, int opt_flags, buf_T *buf, win_T *win)
   if ((opt_flags & OPT_LOCAL) && option_is_global_local(opt_idx)) {
     switch (opt_idx) {
     case kOptFormatprg:
-      return &(buf->b_p_fp);
+      return &(ctx.buf->b_p_fp);
     case kOptFindfunc:
-      return &(buf->b_p_ffu);
+      return &(ctx.buf->b_p_ffu);
     case kOptErrorformat:
-      return &(buf->b_p_efm);
+      return &(ctx.buf->b_p_efm);
     case kOptGrepprg:
-      return &(buf->b_p_gp);
+      return &(ctx.buf->b_p_gp);
     case kOptMakeprg:
-      return &(buf->b_p_mp);
+      return &(ctx.buf->b_p_mp);
     case kOptEqualprg:
-      return &(buf->b_p_ep);
+      return &(ctx.buf->b_p_ep);
     case kOptKeywordprg:
-      return &(buf->b_p_kp);
+      return &(ctx.buf->b_p_kp);
     case kOptPath:
-      return &(buf->b_p_path);
+      return &(ctx.buf->b_p_path);
     case kOptAutoread:
-      return &(buf->b_p_ar);
+      return &(ctx.buf->b_p_ar);
     case kOptTags:
-      return &(buf->b_p_tags);
+      return &(ctx.buf->b_p_tags);
     case kOptTagcase:
-      return &(buf->b_p_tc);
+      return &(ctx.buf->b_p_tc);
     case kOptSidescrolloff:
-      return &(win->w_p_siso);
+      return &(ctx.win->w_p_siso);
     case kOptScrolloff:
-      return &(win->w_p_so);
+      return &(ctx.win->w_p_so);
     case kOptDefine:
-      return &(buf->b_p_def);
+      return &(ctx.buf->b_p_def);
     case kOptInclude:
-      return &(buf->b_p_inc);
+      return &(ctx.buf->b_p_inc);
     case kOptCompleteopt:
-      return &(buf->b_p_cot);
+      return &(ctx.buf->b_p_cot);
     case kOptDictionary:
-      return &(buf->b_p_dict);
+      return &(ctx.buf->b_p_dict);
     case kOptThesaurus:
-      return &(buf->b_p_tsr);
+      return &(ctx.buf->b_p_tsr);
     case kOptThesaurusfunc:
-      return &(buf->b_p_tsrfu);
+      return &(ctx.buf->b_p_tsrfu);
     case kOptTagfunc:
-      return &(buf->b_p_tfu);
+      return &(ctx.buf->b_p_tfu);
     case kOptShowbreak:
-      return &(win->w_p_sbr);
+      return &(ctx.win->w_p_sbr);
     case kOptStatusline:
-      return &(win->w_p_stl);
+      return &(ctx.win->w_p_stl);
     case kOptWinbar:
-      return &(win->w_p_wbr);
+      return &(ctx.win->w_p_wbr);
     case kOptUndolevels:
-      return &(buf->b_p_ul);
+      return &(ctx.buf->b_p_ul);
     case kOptLispwords:
-      return &(buf->b_p_lw);
+      return &(ctx.buf->b_p_lw);
     case kOptBackupcopy:
-      return &(buf->b_p_bkc);
+      return &(ctx.buf->b_p_bkc);
     case kOptMakeencoding:
-      return &(buf->b_p_menc);
+      return &(ctx.buf->b_p_menc);
     case kOptFillchars:
-      return &(win->w_p_fcs);
+      return &(ctx.win->w_p_fcs);
     case kOptListchars:
-      return &(win->w_p_lcs);
+      return &(ctx.win->w_p_lcs);
     case kOptVirtualedit:
-      return &(win->w_p_ve);
+      return &(ctx.win->w_p_ve);
     default:
       abort();
     }
   }
-  return get_varp_from(p, buf, win);
-}
-
-/// Get pointer to option variable, depending on local or global scope.
-///
-/// @param  opt_flags  Option flags (can be OPT_LOCAL, OPT_GLOBAL or a combination).
-void *get_varp_scope(vimoption_T *p, int opt_flags)
-{
-  return get_varp_scope_from(p, opt_flags, curbuf, curwin);
+  return get_varp_from(p, ctx);
 }
 
-/// Get pointer to option variable at 'opt_idx', depending on local or global
-/// scope.
-void *get_option_varp_scope_from(OptIndex opt_idx, int opt_flags, buf_T *buf, win_T *win)
-{
-  return get_varp_scope_from(&(options[opt_idx]), opt_flags, buf, win);
-}
-
-void *get_varp_from(vimoption_T *p, buf_T *buf, win_T *win)
+void *get_varp_from(vimoption_T *p, OptCtx ctx)
 {
   OptIndex opt_idx = get_opt_idx(p);
 
@@ -4561,299 +4436,330 @@ void *get_varp_from(vimoption_T *p, buf_T *buf, win_T *win)
   switch (opt_idx) {
   // global option with local value: use local value if it's been set
   case kOptEqualprg:
-    return *buf->b_p_ep != NUL ? &buf->b_p_ep : p->var;
+    return *ctx.buf->b_p_ep != NUL ? &ctx.buf->b_p_ep : p->var;
   case kOptKeywordprg:
-    return *buf->b_p_kp != NUL ? &buf->b_p_kp : p->var;
+    return *ctx.buf->b_p_kp != NUL ? &ctx.buf->b_p_kp : p->var;
   case kOptPath:
-    return *buf->b_p_path != NUL ? &(buf->b_p_path) : p->var;
+    return *ctx.buf->b_p_path != NUL ? &(ctx.buf->b_p_path) : p->var;
   case kOptAutoread:
-    return buf->b_p_ar >= 0 ? &(buf->b_p_ar) : p->var;
+    return ctx.buf->b_p_ar >= 0 ? &(ctx.buf->b_p_ar) : p->var;
   case kOptTags:
-    return *buf->b_p_tags != NUL ? &(buf->b_p_tags) : p->var;
+    return *ctx.buf->b_p_tags != NUL ? &(ctx.buf->b_p_tags) : p->var;
   case kOptTagcase:
-    return *buf->b_p_tc != NUL ? &(buf->b_p_tc) : p->var;
+    return *ctx.buf->b_p_tc != NUL ? &(ctx.buf->b_p_tc) : p->var;
   case kOptSidescrolloff:
-    return win->w_p_siso >= 0 ? &(win->w_p_siso) : p->var;
+    return ctx.win->w_p_siso >= 0 ? &(ctx.win->w_p_siso) : p->var;
   case kOptScrolloff:
-    return win->w_p_so >= 0 ? &(win->w_p_so) : p->var;
+    return ctx.win->w_p_so >= 0 ? &(ctx.win->w_p_so) : p->var;
   case kOptBackupcopy:
-    return *buf->b_p_bkc != NUL ? &(buf->b_p_bkc) : p->var;
+    return *ctx.buf->b_p_bkc != NUL ? &(ctx.buf->b_p_bkc) : p->var;
   case kOptDefine:
-    return *buf->b_p_def != NUL ? &(buf->b_p_def) : p->var;
+    return *ctx.buf->b_p_def != NUL ? &(ctx.buf->b_p_def) : p->var;
   case kOptInclude:
-    return *buf->b_p_inc != NUL ? &(buf->b_p_inc) : p->var;
+    return *ctx.buf->b_p_inc != NUL ? &(ctx.buf->b_p_inc) : p->var;
   case kOptCompleteopt:
-    return *buf->b_p_cot != NUL ? &(buf->b_p_cot) : p->var;
+    return *ctx.buf->b_p_cot != NUL ? &(ctx.buf->b_p_cot) : p->var;
   case kOptDictionary:
-    return *buf->b_p_dict != NUL ? &(buf->b_p_dict) : p->var;
+    return *ctx.buf->b_p_dict != NUL ? &(ctx.buf->b_p_dict) : p->var;
   case kOptThesaurus:
-    return *buf->b_p_tsr != NUL ? &(buf->b_p_tsr) : p->var;
+    return *ctx.buf->b_p_tsr != NUL ? &(ctx.buf->b_p_tsr) : p->var;
   case kOptThesaurusfunc:
-    return *buf->b_p_tsrfu != NUL ? &(buf->b_p_tsrfu) : p->var;
+    return *ctx.buf->b_p_tsrfu != NUL ? &(ctx.buf->b_p_tsrfu) : p->var;
   case kOptFormatprg:
-    return *buf->b_p_fp != NUL ? &(buf->b_p_fp) : p->var;
+    return *ctx.buf->b_p_fp != NUL ? &(ctx.buf->b_p_fp) : p->var;
   case kOptFindfunc:
-    return *buf->b_p_ffu != NUL ? &(buf->b_p_ffu) : p->var;
+    return *ctx.buf->b_p_ffu != NUL ? &(ctx.buf->b_p_ffu) : p->var;
   case kOptErrorformat:
-    return *buf->b_p_efm != NUL ? &(buf->b_p_efm) : p->var;
+    return *ctx.buf->b_p_efm != NUL ? &(ctx.buf->b_p_efm) : p->var;
   case kOptGrepprg:
-    return *buf->b_p_gp != NUL ? &(buf->b_p_gp) : p->var;
+    return *ctx.buf->b_p_gp != NUL ? &(ctx.buf->b_p_gp) : p->var;
   case kOptMakeprg:
-    return *buf->b_p_mp != NUL ? &(buf->b_p_mp) : p->var;
+    return *ctx.buf->b_p_mp != NUL ? &(ctx.buf->b_p_mp) : p->var;
   case kOptShowbreak:
-    return *win->w_p_sbr != NUL ? &(win->w_p_sbr) : p->var;
+    return *ctx.win->w_p_sbr != NUL ? &(ctx.win->w_p_sbr) : p->var;
   case kOptStatusline:
-    return *win->w_p_stl != NUL ? &(win->w_p_stl) : p->var;
+    return *ctx.win->w_p_stl != NUL ? &(ctx.win->w_p_stl) : p->var;
   case kOptWinbar:
-    return *win->w_p_wbr != NUL ? &(win->w_p_wbr) : p->var;
+    return *ctx.win->w_p_wbr != NUL ? &(ctx.win->w_p_wbr) : p->var;
   case kOptUndolevels:
-    return buf->b_p_ul != NO_LOCAL_UNDOLEVEL ? &(buf->b_p_ul) : p->var;
+    return ctx.buf->b_p_ul != NO_LOCAL_UNDOLEVEL ? &(ctx.buf->b_p_ul) : p->var;
   case kOptLispwords:
-    return *buf->b_p_lw != NUL ? &(buf->b_p_lw) : p->var;
+    return *ctx.buf->b_p_lw != NUL ? &(ctx.buf->b_p_lw) : p->var;
   case kOptMakeencoding:
-    return *buf->b_p_menc != NUL ? &(buf->b_p_menc) : p->var;
+    return *ctx.buf->b_p_menc != NUL ? &(ctx.buf->b_p_menc) : p->var;
   case kOptFillchars:
-    return *win->w_p_fcs != NUL ? &(win->w_p_fcs) : p->var;
+    return *ctx.win->w_p_fcs != NUL ? &(ctx.win->w_p_fcs) : p->var;
   case kOptListchars:
-    return *win->w_p_lcs != NUL ? &(win->w_p_lcs) : p->var;
+    return *ctx.win->w_p_lcs != NUL ? &(ctx.win->w_p_lcs) : p->var;
   case kOptVirtualedit:
-    return *win->w_p_ve != NUL ? &win->w_p_ve : p->var;
+    return *ctx.win->w_p_ve != NUL ? &ctx.win->w_p_ve : p->var;
 
   case kOptArabic:
-    return &(win->w_p_arab);
+    return &(ctx.win->w_p_arab);
   case kOptList:
-    return &(win->w_p_list);
+    return &(ctx.win->w_p_list);
   case kOptSpell:
-    return &(win->w_p_spell);
+    return &(ctx.win->w_p_spell);
   case kOptCursorcolumn:
-    return &(win->w_p_cuc);
+    return &(ctx.win->w_p_cuc);
   case kOptCursorline:
-    return &(win->w_p_cul);
+    return &(ctx.win->w_p_cul);
   case kOptCursorlineopt:
-    return &(win->w_p_culopt);
+    return &(ctx.win->w_p_culopt);
   case kOptColorcolumn:
-    return &(win->w_p_cc);
+    return &(ctx.win->w_p_cc);
   case kOptDiff:
-    return &(win->w_p_diff);
+    return &(ctx.win->w_p_diff);
   case kOptFoldcolumn:
-    return &(win->w_p_fdc);
+    return &(ctx.win->w_p_fdc);
   case kOptFoldenable:
-    return &(win->w_p_fen);
+    return &(ctx.win->w_p_fen);
   case kOptFoldignore:
-    return &(win->w_p_fdi);
+    return &(ctx.win->w_p_fdi);
   case kOptFoldlevel:
-    return &(win->w_p_fdl);
+    return &(ctx.win->w_p_fdl);
   case kOptFoldmethod:
-    return &(win->w_p_fdm);
+    return &(ctx.win->w_p_fdm);
   case kOptFoldminlines:
-    return &(win->w_p_fml);
+    return &(ctx.win->w_p_fml);
   case kOptFoldnestmax:
-    return &(win->w_p_fdn);
+    return &(ctx.win->w_p_fdn);
   case kOptFoldexpr:
-    return &(win->w_p_fde);
+    return &(ctx.win->w_p_fde);
   case kOptFoldtext:
-    return &(win->w_p_fdt);
+    return &(ctx.win->w_p_fdt);
   case kOptFoldmarker:
-    return &(win->w_p_fmr);
+    return &(ctx.win->w_p_fmr);
   case kOptNumber:
-    return &(win->w_p_nu);
+    return &(ctx.win->w_p_nu);
   case kOptRelativenumber:
-    return &(win->w_p_rnu);
+    return &(ctx.win->w_p_rnu);
   case kOptNumberwidth:
-    return &(win->w_p_nuw);
+    return &(ctx.win->w_p_nuw);
   case kOptWinfixbuf:
-    return &(win->w_p_wfb);
+    return &(ctx.win->w_p_wfb);
   case kOptWinfixheight:
-    return &(win->w_p_wfh);
+    return &(ctx.win->w_p_wfh);
   case kOptWinfixwidth:
-    return &(win->w_p_wfw);
+    return &(ctx.win->w_p_wfw);
   case kOptPreviewwindow:
-    return &(win->w_p_pvw);
+    return &(ctx.win->w_p_pvw);
   case kOptRightleft:
-    return &(win->w_p_rl);
+    return &(ctx.win->w_p_rl);
   case kOptRightleftcmd:
-    return &(win->w_p_rlc);
+    return &(ctx.win->w_p_rlc);
   case kOptScroll:
-    return &(win->w_p_scr);
+    return &(ctx.win->w_p_scr);
   case kOptSmoothscroll:
-    return &(win->w_p_sms);
+    return &(ctx.win->w_p_sms);
   case kOptWrap:
-    return &(win->w_p_wrap);
+    return &(ctx.win->w_p_wrap);
   case kOptLinebreak:
-    return &(win->w_p_lbr);
+    return &(ctx.win->w_p_lbr);
   case kOptBreakindent:
-    return &(win->w_p_bri);
+    return &(ctx.win->w_p_bri);
   case kOptBreakindentopt:
-    return &(win->w_p_briopt);
+    return &(ctx.win->w_p_briopt);
   case kOptScrollbind:
-    return &(win->w_p_scb);
+    return &(ctx.win->w_p_scb);
   case kOptCursorbind:
-    return &(win->w_p_crb);
+    return &(ctx.win->w_p_crb);
   case kOptConcealcursor:
-    return &(win->w_p_cocu);
+    return &(ctx.win->w_p_cocu);
   case kOptConceallevel:
-    return &(win->w_p_cole);
+    return &(ctx.win->w_p_cole);
 
   case kOptAutoindent:
-    return &(buf->b_p_ai);
+    return &(ctx.buf->b_p_ai);
   case kOptBinary:
-    return &(buf->b_p_bin);
+    return &(ctx.buf->b_p_bin);
   case kOptBomb:
-    return &(buf->b_p_bomb);
+    return &(ctx.buf->b_p_bomb);
   case kOptBufhidden:
-    return &(buf->b_p_bh);
+    return &(ctx.buf->b_p_bh);
   case kOptBuftype:
-    return &(buf->b_p_bt);
+    return &(ctx.buf->b_p_bt);
   case kOptBuflisted:
-    return &(buf->b_p_bl);
+    return &(ctx.buf->b_p_bl);
   case kOptChannel:
-    return &(buf->b_p_channel);
+    return &(ctx.buf->b_p_channel);
   case kOptCopyindent:
-    return &(buf->b_p_ci);
+    return &(ctx.buf->b_p_ci);
   case kOptCindent:
-    return &(buf->b_p_cin);
+    return &(ctx.buf->b_p_cin);
   case kOptCinkeys:
-    return &(buf->b_p_cink);
+    return &(ctx.buf->b_p_cink);
   case kOptCinoptions:
-    return &(buf->b_p_cino);
+    return &(ctx.buf->b_p_cino);
   case kOptCinscopedecls:
-    return &(buf->b_p_cinsd);
+    return &(ctx.buf->b_p_cinsd);
   case kOptCinwords:
-    return &(buf->b_p_cinw);
+    return &(ctx.buf->b_p_cinw);
   case kOptComments:
-    return &(buf->b_p_com);
+    return &(ctx.buf->b_p_com);
   case kOptCommentstring:
-    return &(buf->b_p_cms);
+    return &(ctx.buf->b_p_cms);
   case kOptComplete:
-    return &(buf->b_p_cpt);
+    return &(ctx.buf->b_p_cpt);
 #ifdef BACKSLASH_IN_FILENAME
   case kOptCompleteslash:
-    return &(buf->b_p_csl);
+    return &(ctx.buf->b_p_csl);
 #endif
   case kOptCompletefunc:
-    return &(buf->b_p_cfu);
+    return &(ctx.buf->b_p_cfu);
   case kOptOmnifunc:
-    return &(buf->b_p_ofu);
+    return &(ctx.buf->b_p_ofu);
   case kOptEndoffile:
-    return &(buf->b_p_eof);
+    return &(ctx.buf->b_p_eof);
   case kOptEndofline:
-    return &(buf->b_p_eol);
+    return &(ctx.buf->b_p_eol);
   case kOptFixendofline:
-    return &(buf->b_p_fixeol);
+    return &(ctx.buf->b_p_fixeol);
   case kOptExpandtab:
-    return &(buf->b_p_et);
+    return &(ctx.buf->b_p_et);
   case kOptFileencoding:
-    return &(buf->b_p_fenc);
+    return &(ctx.buf->b_p_fenc);
   case kOptFileformat:
-    return &(buf->b_p_ff);
+    return &(ctx.buf->b_p_ff);
   case kOptFiletype:
-    return &(buf->b_p_ft);
+    return &(ctx.buf->b_p_ft);
   case kOptFormatoptions:
-    return &(buf->b_p_fo);
+    return &(ctx.buf->b_p_fo);
   case kOptFormatlistpat:
-    return &(buf->b_p_flp);
+    return &(ctx.buf->b_p_flp);
   case kOptIminsert:
-    return &(buf->b_p_iminsert);
+    return &(ctx.buf->b_p_iminsert);
   case kOptImsearch:
-    return &(buf->b_p_imsearch);
+    return &(ctx.buf->b_p_imsearch);
   case kOptInfercase:
-    return &(buf->b_p_inf);
+    return &(ctx.buf->b_p_inf);
   case kOptIskeyword:
-    return &(buf->b_p_isk);
+    return &(ctx.buf->b_p_isk);
   case kOptIncludeexpr:
-    return &(buf->b_p_inex);
+    return &(ctx.buf->b_p_inex);
   case kOptIndentexpr:
-    return &(buf->b_p_inde);
+    return &(ctx.buf->b_p_inde);
   case kOptIndentkeys:
-    return &(buf->b_p_indk);
+    return &(ctx.buf->b_p_indk);
   case kOptFormatexpr:
-    return &(buf->b_p_fex);
+    return &(ctx.buf->b_p_fex);
   case kOptLisp:
-    return &(buf->b_p_lisp);
+    return &(ctx.buf->b_p_lisp);
   case kOptLispoptions:
-    return &(buf->b_p_lop);
+    return &(ctx.buf->b_p_lop);
   case kOptModeline:
-    return &(buf->b_p_ml);
+    return &(ctx.buf->b_p_ml);
   case kOptMatchpairs:
-    return &(buf->b_p_mps);
+    return &(ctx.buf->b_p_mps);
   case kOptModifiable:
-    return &(buf->b_p_ma);
+    return &(ctx.buf->b_p_ma);
   case kOptModified:
-    return &(buf->b_changed);
+    return &(ctx.buf->b_changed);
   case kOptNrformats:
-    return &(buf->b_p_nf);
+    return &(ctx.buf->b_p_nf);
   case kOptPreserveindent:
-    return &(buf->b_p_pi);
+    return &(ctx.buf->b_p_pi);
   case kOptQuoteescape:
-    return &(buf->b_p_qe);
+    return &(ctx.buf->b_p_qe);
   case kOptReadonly:
-    return &(buf->b_p_ro);
+    return &(ctx.buf->b_p_ro);
   case kOptScrollback:
-    return &(buf->b_p_scbk);
+    return &(ctx.buf->b_p_scbk);
   case kOptSmartindent:
-    return &(buf->b_p_si);
+    return &(ctx.buf->b_p_si);
   case kOptSofttabstop:
-    return &(buf->b_p_sts);
+    return &(ctx.buf->b_p_sts);
   case kOptSuffixesadd:
-    return &(buf->b_p_sua);
+    return &(ctx.buf->b_p_sua);
   case kOptSwapfile:
-    return &(buf->b_p_swf);
+    return &(ctx.buf->b_p_swf);
   case kOptSynmaxcol:
-    return &(buf->b_p_smc);
+    return &(ctx.buf->b_p_smc);
   case kOptSyntax:
-    return &(buf->b_p_syn);
+    return &(ctx.buf->b_p_syn);
   case kOptSpellcapcheck:
-    return &(win->w_s->b_p_spc);
+    return &(ctx.win->w_s->b_p_spc);
   case kOptSpellfile:
-    return &(win->w_s->b_p_spf);
+    return &(ctx.win->w_s->b_p_spf);
   case kOptSpelllang:
-    return &(win->w_s->b_p_spl);
+    return &(ctx.win->w_s->b_p_spl);
   case kOptSpelloptions:
-    return &(win->w_s->b_p_spo);
+    return &(ctx.win->w_s->b_p_spo);
   case kOptShiftwidth:
-    return &(buf->b_p_sw);
+    return &(ctx.buf->b_p_sw);
   case kOptTagfunc:
-    return &(buf->b_p_tfu);
+    return &(ctx.buf->b_p_tfu);
   case kOptTabstop:
-    return &(buf->b_p_ts);
+    return &(ctx.buf->b_p_ts);
   case kOptTextwidth:
-    return &(buf->b_p_tw);
+    return &(ctx.buf->b_p_tw);
   case kOptUndofile:
-    return &(buf->b_p_udf);
+    return &(ctx.buf->b_p_udf);
   case kOptWrapmargin:
-    return &(buf->b_p_wm);
+    return &(ctx.buf->b_p_wm);
   case kOptVarsofttabstop:
-    return &(buf->b_p_vsts);
+    return &(ctx.buf->b_p_vsts);
   case kOptVartabstop:
-    return &(buf->b_p_vts);
+    return &(ctx.buf->b_p_vts);
   case kOptKeymap:
-    return &(buf->b_p_keymap);
+    return &(ctx.buf->b_p_keymap);
   case kOptSigncolumn:
-    return &(win->w_p_scl);
+    return &(ctx.win->w_p_scl);
   case kOptWinhighlight:
-    return &(win->w_p_winhl);
+    return &(ctx.win->w_p_winhl);
   case kOptWinblend:
-    return &(win->w_p_winbl);
+    return &(ctx.win->w_p_winbl);
   case kOptStatuscolumn:
-    return &(win->w_p_stc);
+    return &(ctx.win->w_p_stc);
   default:
     iemsg(_("E356: get_varp ERROR"));
   }
   // always return a valid pointer to avoid a crash!
-  return &(buf->b_p_wm);
+  return &(ctx.buf->b_p_wm);
 }
 
-/// Get option index from option pointer
-static inline OptIndex get_opt_idx(vimoption_T *opt)
-  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
+/// Get the current context for options.
+OptCtx option_ctx(void)
 {
-  return (OptIndex)(opt - options);
+  return (OptCtx){ .buf = curbuf, .win = curwin };
+}
+
+/// Get the context for options from a scope and pointer to target.
+///
+/// @param  scope      Option scope. See OptScope in option.h.
+/// @param  from       Pointer to target buffer/window/etc.
+OptCtx option_ctx_from(OptScope scope, void *from)
+{
+  switch (scope) {
+  case kOptScopeGlobal:
+    return option_ctx();
+  case kOptScopeBuf:
+    return (OptCtx){ .buf = (buf_T *)from, .win = curwin };
+  case kOptScopeWin:
+    return (OptCtx){ .buf = ((win_T *)from)->w_buffer, .win = (win_T *)from };
+  }
+  UNREACHABLE;
+}
+
+/// Get pointer to option variable, depending on local or global scope.
+///
+/// @param  opt_flags  Option flags (can be OPT_LOCAL, OPT_GLOBAL or a combination).
+void *get_varp_scope(vimoption_T *p, int opt_flags)
+{
+  return get_varp_scope_from(p, opt_flags, option_ctx());
 }
 
 /// Get pointer to option variable.
 static inline void *get_varp(vimoption_T *p)
 {
-  return get_varp_from(p, curbuf, curwin);
+  return get_varp_from(p, option_ctx());
+}
+
+/// Get option index from option pointer
+static inline OptIndex get_opt_idx(vimoption_T *opt)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
+{
+  return (OptIndex)(opt - options);
 }
 
 /// Get the value of 'equalprg', either the buffer-local one or the global one.
@@ -5799,9 +5705,7 @@ int ExpandSettingSubtract(expand_T *xp, regmatch_T *regmatch, int *numMatches, c
     return ExpandOldSetting(numMatches, matches);
   }
 
-  char *option_val = *(char **)get_option_varp_scope_from(expand_option_idx,
-                                                          expand_option_flags,
-                                                          curbuf, curwin);
+  char *option_val = *(char **)get_varp_scope(get_option(expand_option_idx), expand_option_flags);
 
   uint32_t option_flags = options[expand_option_idx].flags;
 
diff --git a/src/nvim/option_defs.h b/src/nvim/option_defs.h
index 832e03148a..b76532b1eb 100644
--- a/src/nvim/option_defs.h
+++ b/src/nvim/option_defs.h
@@ -81,6 +81,12 @@ typedef struct {
   OptValData data;
 } OptVal;
 
+/// Context that an option is being set for.
+typedef struct {
+  win_T *win;
+  buf_T *buf;
+} OptCtx;
+
 /// :set operator types
 typedef enum {
   OP_NONE = 0,
@@ -122,8 +128,7 @@ typedef struct {
   /// length of the error buffer
   size_t os_errbuflen;
 
-  void *os_win;
-  void *os_buf;
+  OptCtx os_ctx;
 } optset_T;
 
 /// Type for the callback function that is invoked after an option value is
@@ -192,3 +197,12 @@ typedef struct {
   OptVal def_val;                    ///< default value
   LastSet last_set;                  ///< script in which the option was last set
 } vimoption_T;
+
+/// Execute code with autocmd context
+#define WITH_AUCMD_CONTEXT(ctx, code) \
+  do { \
+    aco_save_T _aco; \
+    aucmd_prepbuf_win(&_aco, ctx.buf, ctx.win); \
+    code; \
+    aucmd_restbuf(&_aco); \
+  } while (0)
diff --git a/src/nvim/optionstr.c b/src/nvim/optionstr.c
index 9b7b50ae04..632b4af573 100644
--- a/src/nvim/optionstr.c
+++ b/src/nvim/optionstr.c
@@ -567,7 +567,7 @@ int expand_set_backspace(optexpand_T *args, int *numMatches, char ***matches)
 /// The 'backupcopy' option is changed.
 const char *did_set_backupcopy(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   const char *oldval = args->os_oldval.string.data;
   int opt_flags = args->os_flags;
   char *bkc = p_bkc;
@@ -655,7 +655,7 @@ const char *did_set_breakat(optset_T *args FUNC_ATTR_UNUSED)
 /// The 'breakindentopt' option is changed.
 const char *did_set_breakindentopt(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   char **varp = (char **)args->os_varp;
 
   if (briopt_check(*varp, varp == &win->w_p_briopt ? win : NULL) == FAIL) {
@@ -682,7 +682,7 @@ int expand_set_breakindentopt(optexpand_T *args, int *numMatches, char ***matche
 /// The 'bufhidden' option is changed.
 const char *did_set_bufhidden(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   return did_set_opt_strings(buf->b_p_bh, opt_bh_values, false);
 }
 
@@ -698,8 +698,8 @@ int expand_set_bufhidden(optexpand_T *args, int *numMatches, char ***matches)
 /// The 'buftype' option is changed.
 const char *did_set_buftype(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
-  win_T *win = (win_T *)args->os_win;
+  buf_T *buf = args->os_ctx.buf;
+  win_T *win = args->os_ctx.win;
   // When 'buftype' is set, check for valid value.
   if ((buf->terminal && buf->b_p_bt[0] != 't')
       || (!buf->terminal && buf->b_p_bt[0] == 't')
@@ -780,7 +780,7 @@ static const char *did_set_global_chars_option(win_T *win, char *val, CharsOptio
 /// The 'fillchars' option or the 'listchars' option is changed.
 const char *did_set_chars_option(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   char **varp = (char **)args->os_varp;
   const char *errmsg = NULL;
 
@@ -815,7 +815,7 @@ int expand_set_chars_option(optexpand_T *args, int *numMatches, char ***matches)
 /// The 'cinoptions' option is changed.
 const char *did_set_cinoptions(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   // TODO(vim): recognize errors
   parse_cino(buf);
 
@@ -840,7 +840,7 @@ int expand_set_clipboard(optexpand_T *args, int *numMatches, char ***matches)
 /// The 'colorcolumn' option is changed.
 const char *did_set_colorcolumn(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   char **varp = (char **)args->os_varp;
   return check_colorcolumn(*varp, varp == &win->w_p_cc ? win : NULL);
 }
@@ -985,7 +985,7 @@ const char *did_set_completeitemalign(optset_T *args)
 /// The 'completeopt' option is changed.
 const char *did_set_completeopt(optset_T *args FUNC_ATTR_UNUSED)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   char *cot = p_cot;
   unsigned *flags = &cot_flags;
 
@@ -1021,7 +1021,7 @@ int expand_set_completeopt(optexpand_T *args, int *numMatches, char ***matches)
 /// The 'completeslash' option is changed.
 const char *did_set_completeslash(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   if (check_opt_strings(p_csl, opt_csl_values, false) != OK
       || check_opt_strings(buf->b_p_csl, opt_csl_values, false) != OK) {
     return e_invarg;
@@ -1068,7 +1068,7 @@ int expand_set_cpoptions(optexpand_T *args, int *numMatches, char ***matches)
 /// The 'cursorlineopt' option is changed.
 const char *did_set_cursorlineopt(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   char **varp = (char **)args->os_varp;
 
   // This could be changed to use opt_strings_flags() instead.
@@ -1176,12 +1176,12 @@ int expand_set_eadirection(optexpand_T *args, int *numMatches, char ***matches)
 /// options is changed.
 const char *did_set_encoding(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   char **varp = (char **)args->os_varp;
   int opt_flags = args->os_flags;
   // Get the global option to compare with, otherwise we would have to check
   // two values for all local options.
-  char **gvarp = (char **)get_option_varp_scope_from(args->os_idx, OPT_GLOBAL, buf, NULL);
+  char **gvarp = (char **)get_varp_scope_from(get_option(args->os_idx), OPT_GLOBAL, args->os_ctx);
 
   if (gvarp == &p_fenc) {
     if (!MODIFIABLE(buf) && opt_flags != OPT_GLOBAL) {
@@ -1246,7 +1246,7 @@ int expand_set_eventignore(optexpand_T *args, int *numMatches, char ***matches)
 /// The 'fileformat' option is changed.
 const char *did_set_fileformat(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   char **varp = (char **)args->os_varp;
   const char *oldval = args->os_oldval.string.data;
   int opt_flags = args->os_flags;
@@ -1347,7 +1347,7 @@ int expand_set_foldcolumn(optexpand_T *args, int *numMatches, char ***matches)
 /// The 'foldexpr' option is changed.
 const char *did_set_foldexpr(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   did_set_optexpr(args);
   if (foldmethodIsExpr(win)) {
     foldUpdateAll(win);
@@ -1358,7 +1358,7 @@ const char *did_set_foldexpr(optset_T *args)
 /// The 'foldignore' option is changed.
 const char *did_set_foldignore(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   if (foldmethodIsIndent(win)) {
     foldUpdateAll(win);
   }
@@ -1368,7 +1368,7 @@ const char *did_set_foldignore(optset_T *args)
 /// The 'foldmarker' option is changed.
 const char *did_set_foldmarker(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   char **varp = (char **)args->os_varp;
   char *p = vim_strchr(*varp, ',');
 
@@ -1390,7 +1390,7 @@ const char *did_set_foldmarker(optset_T *args)
 /// The 'foldmethod' option is changed.
 const char *did_set_foldmethod(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   char **varp = (char **)args->os_varp;
   if (check_opt_strings(*varp, opt_fdm_values, false) != OK || **varp == NUL) {
     return e_invarg;
@@ -1536,7 +1536,7 @@ const char *did_set_iskeyword(optset_T *args)
 /// changed.
 const char *did_set_isopt(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   // 'isident', 'iskeyword', 'isprint' or 'isfname' option: refill g_chartab[]
   // If the new option is invalid, use old value.
   // 'lisp' option: refill g_chartab[] for '-' char
@@ -1565,7 +1565,7 @@ int expand_set_jumpoptions(optexpand_T *args, int *numMatches, char ***matches)
 /// The 'keymap' option has changed.
 const char *did_set_keymap(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   char **varp = (char **)args->os_varp;
   int opt_flags = args->os_flags;
 
@@ -2053,7 +2053,7 @@ int expand_set_showcmdloc(optexpand_T *args, int *numMatches, char ***matches)
 /// The 'signcolumn' option is changed.
 const char *did_set_signcolumn(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   char **varp = (char **)args->os_varp;
   const char *oldval = args->os_oldval.string.data;
   if (check_signcolumn(*varp, varp == &win->w_p_scl ? win : NULL) != OK) {
@@ -2079,7 +2079,7 @@ int expand_set_signcolumn(optexpand_T *args, int *numMatches, char ***matches)
 /// The 'spellcapcheck' option is changed.
 const char *did_set_spellcapcheck(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   // When 'spellcapcheck' is set compile the regexp program.
   return compile_cap_prog(win->w_s);
 }
@@ -2113,7 +2113,7 @@ const char *did_set_spelllang(optset_T *args)
 /// The 'spelloptions' option is changed.
 const char *did_set_spelloptions(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   int opt_flags = args->os_flags;
   const char *val = args->os_newval.string.data;
 
@@ -2189,7 +2189,7 @@ const char *did_set_statusline(optset_T *args)
 static const char *did_set_statustabline_rulerformat(optset_T *args, bool rulerformat,
                                                      bool statuscolumn)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   char **varp = (char **)args->os_varp;
   if (rulerformat) {       // reset ru_wid first
     ru_wid = 0;
@@ -2264,7 +2264,7 @@ const char *did_set_tabline(optset_T *args)
 /// The 'tagcase' option is changed.
 const char *did_set_tagcase(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   int opt_flags = args->os_flags;
 
   unsigned *flags;
@@ -2337,7 +2337,7 @@ const char *did_set_titlestring(optset_T *args)
 /// The 'varsofttabstop' option is changed.
 const char *did_set_varsofttabstop(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
   char **varp = (char **)args->os_varp;
 
   if (!(*varp)[0] || ((*varp)[0] == '0' && !(*varp)[1])) {
@@ -2367,8 +2367,8 @@ const char *did_set_varsofttabstop(optset_T *args)
 /// The 'varstabstop' option is changed.
 const char *did_set_vartabstop(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
-  win_T *win = (win_T *)args->os_win;
+  buf_T *buf = args->os_ctx.buf;
+  win_T *win = args->os_ctx.win;
   char **varp = (char **)args->os_varp;
 
   if (!(*varp)[0] || ((*varp)[0] == '0' && !(*varp)[1])) {
@@ -2417,7 +2417,7 @@ const char *did_set_viewoptions(optset_T *args FUNC_ATTR_UNUSED)
 /// The 'virtualedit' option is changed.
 const char *did_set_virtualedit(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
 
   char *ve = p_ve;
   unsigned *flags = &ve_flags;
@@ -2527,7 +2527,7 @@ const char *did_set_winbar(optset_T *args)
 /// The 'winhighlight' option is changed.
 const char *did_set_winhighlight(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
+  win_T *win = args->os_ctx.win;
   char **varp = (char **)args->os_varp;
   if (!parse_winhl_opt(*varp, varp == &win->w_p_winhl ? win : NULL)) {
     return e_invarg;
diff --git a/src/nvim/tag.c b/src/nvim/tag.c
index c676b00986..9375629abc 100644
--- a/src/nvim/tag.c
+++ b/src/nvim/tag.c
@@ -228,7 +228,7 @@ static Callback tfu_cb;          // 'tagfunc' callback function
 /// a function (string), or function(<name>) or funcref(<name>) or a lambda.
 const char *did_set_tagfunc(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  buf_T *buf = args->os_ctx.buf;
 
   callback_free(&tfu_cb);
   callback_free(&buf->b_tfu_cb);
diff --git a/src/nvim/winfloat.c b/src/nvim/winfloat.c
index 3e791e2beb..78f3551087 100644
--- a/src/nvim/winfloat.c
+++ b/src/nvim/winfloat.c
@@ -411,8 +411,8 @@ win_T *win_float_create(bool enter, bool new_buf)
       return handle_error_and_cleanup(wp, &err);
     }
     buf->b_p_bl = false;  // unlist
-    set_option_direct_for(kOptBufhidden, STATIC_CSTR_AS_OPTVAL("wipe"), OPT_LOCAL, 0,
-                          kOptScopeBuf, buf);
+    set_option_direct_for(kOptBufhidden, STATIC_CSTR_AS_OPTVAL("wipe"),
+                          option_ctx_from(kOptScopeBuf, buf), OPT_LOCAL, 0);
     win_set_buf(wp, buf, &err);
     if (ERROR_SET(&err)) {
       return handle_error_and_cleanup(wp, &err);
diff --git a/test/functional/lua/with_spec.lua b/test/functional/lua/with_spec.lua
index 92e798e7f3..a68a7722a4 100644
--- a/test/functional/lua/with_spec.lua
+++ b/test/functional/lua/with_spec.lua
@@ -882,11 +882,7 @@ describe('vim._with', function()
       eq({
         bo = { cms_cur = '// %s', cms_other = '-- %s', ul_cur = 250, ul_other = -123456 },
         wo = { ve_cur = 'insert', ve_other = 'block', winbl_cur = 25, winbl_other = 10 },
-        -- Global `winbl` inside context ideally should be untouched and equal
-        -- to 50. It seems to be equal to 0 because `context.buf` uses
-        -- `aucmd_prepbuf` C approach which has no guarantees about window or
-        -- window option values inside context.
-        go = { cms = '-- %s', ul = 0, ve = 'none', winbl = 0, lmap = 'xy,yx' },
+        go = { cms = '-- %s', ul = 0, ve = 'none', winbl = 50, lmap = 'xy,yx' },
       }, out.inner)
       eq(out.before, out.after)
     end)