feat: get/set namespace properties #28728

ref https://github.com/neovim/neovim/pull/28432
ref https://github.com/neovim/neovim/issues/28469

18 files changed, 285 insertions, 265 deletions

diff --git a/runtime/doc/api.txt b/runtime/doc/api.txt
index 577329ad00..f92a69af4e 100644
--- a/runtime/doc/api.txt
+++ b/runtime/doc/api.txt
@@ -2758,8 +2758,6 @@ nvim_buf_set_extmark({buffer}, {ns_id}, {line}, {col}, {opts})
                   • url: A URL to associate with this extmark. In the TUI, the
                     OSC 8 control sequence is used to generate a clickable
                     hyperlink to this URL.
-                  • scoped: boolean (EXPERIMENTAL) enables "scoping" for the
-                    extmark. See |nvim__win_add_ns()|
 
     Return: ~
         Id of the created/updated extmark
@@ -2841,41 +2839,26 @@ nvim_set_decoration_provider({ns_id}, {opts})
                     ["end", tick]
 <
 
-nvim__win_add_ns({window}, {ns_id})                       *nvim__win_add_ns()*
+nvim__ns_get({ns_id})                                         *nvim__ns_get()*
     EXPERIMENTAL: this API will change in the future.
 
-    Scopes a namespace to the a window, so extmarks in the namespace will be
-    active only in the given window.
+    Get the properties for namespace
 
     Parameters: ~
-      • {window}  Window handle, or 0 for current window
-      • {ns_id}   Namespace
-
-    Return: ~
-        true if the namespace was added, else false
-
-nvim__win_del_ns({window}, {ns_id})                       *nvim__win_del_ns()*
-    EXPERIMENTAL: this API will change in the future.
-
-    Unscopes a namespace (un-binds it from the given scope).
-
-    Parameters: ~
-      • {window}  Window handle, or 0 for current window
-      • {ns_id}   the namespace to remove
+      • {ns_id}  Namespace
 
     Return: ~
-        true if the namespace was removed, else false
+        Map defining the namespace properties, see |nvim__ns_set()|
 
-nvim__win_get_ns({window})                                *nvim__win_get_ns()*
+nvim__ns_set({ns_id}, {opts})                                 *nvim__ns_set()*
     EXPERIMENTAL: this API will change in the future.
 
-    Gets the namespace scopes for a given window.
+    Set some properties for namespace
 
     Parameters: ~
-      • {window}  Window handle, or 0 for current window
-
-    Return: ~
-        a list of namespaces ids
+      • {ns_id}  Namespace
+      • {opts}   Optional parameters to set:
+                 • wins: a list of windows to be scoped in
 
 
 ==============================================================================
diff --git a/runtime/doc/news-0.10.txt b/runtime/doc/news-0.10.txt
index d611eee242..bc868c1099 100644
--- a/runtime/doc/news-0.10.txt
+++ b/runtime/doc/news-0.10.txt
@@ -155,8 +155,6 @@ The following new features were added.
   • |nvim_input_mouse()| supports mouse buttons "x1" and "x2".
   • Added "force_crlf" option field in |nvim_open_term()|.
   • Added |nvim_tabpage_set_win()| to set the current window of a tabpage.
-  • |nvim__win_add_ns()| can bind a |namespace| to a window-local scope(s).
-    • Extmarks opt-in to this scoping via the `scoped` flag of |nvim_buf_set_extmark()|.
   • Mapping APIs now support abbreviations when mode short-name has suffix "a".
   • Floating windows can now show footer with new `footer` and `footer_pos`
     config fields. Uses |hl-FloatFooter| by default.
diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index 2fed1b6b29..b316cc7b04 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -83,7 +83,7 @@ The following new features were added.
 
 API
 
-• TODO
+• |nvim__ns_set()| can set properties for a namespace
 
 DEFAULTS
 
diff --git a/runtime/lua/vim/_meta/api.lua b/runtime/lua/vim/_meta/api.lua
index bb27ee4269..d91b2d08bf 100644
--- a/runtime/lua/vim/_meta/api.lua
+++ b/runtime/lua/vim/_meta/api.lua
@@ -100,6 +100,25 @@ function vim.api.nvim__inspect_cell(grid, row, col) end
 function vim.api.nvim__invalidate_glyph_cache() end
 
 --- @private
+--- EXPERIMENTAL: this API will change in the future.
+---
+--- Get the properties for namespace
+---
+--- @param ns_id integer Namespace
+--- @return vim.api.keyset.ns_opts
+function vim.api.nvim__ns_get(ns_id) end
+
+--- @private
+--- EXPERIMENTAL: this API will change in the future.
+---
+--- Set some properties for namespace
+---
+--- @param ns_id integer Namespace
+--- @param opts vim.api.keyset.ns_opts Optional parameters to set:
+---             • wins: a list of windows to be scoped in
+function vim.api.nvim__ns_set(ns_id, opts) end
+
+--- @private
 --- EXPERIMENTAL: this API may change in the future.
 ---
 --- Instruct Nvim to redraw various components.
@@ -144,36 +163,6 @@ function vim.api.nvim__stats() end
 --- @return any
 function vim.api.nvim__unpack(str) end
 
---- @private
---- EXPERIMENTAL: this API will change in the future.
----
---- Scopes a namespace to the a window, so extmarks in the namespace will be
---- active only in the given window.
----
---- @param window integer Window handle, or 0 for current window
---- @param ns_id integer Namespace
---- @return boolean
-function vim.api.nvim__win_add_ns(window, ns_id) end
-
---- @private
---- EXPERIMENTAL: this API will change in the future.
----
---- Unscopes a namespace (un-binds it from the given scope).
----
---- @param window integer Window handle, or 0 for current window
---- @param ns_id integer the namespace to remove
---- @return boolean
-function vim.api.nvim__win_del_ns(window, ns_id) end
-
---- @private
---- EXPERIMENTAL: this API will change in the future.
----
---- Gets the namespace scopes for a given window.
----
---- @param window integer Window handle, or 0 for current window
---- @return integer[]
-function vim.api.nvim__win_get_ns(window) end
-
 --- Adds a highlight to buffer.
 ---
 --- Useful for plugins that dynamically generate highlights to a buffer (like
@@ -686,8 +675,6 @@ function vim.api.nvim_buf_line_count(buffer) end
 ---             • url: A URL to associate with this extmark. In the TUI, the
 ---               OSC 8 control sequence is used to generate a clickable
 ---               hyperlink to this URL.
----             • scoped: boolean (EXPERIMENTAL) enables "scoping" for the
----               extmark. See `nvim__win_add_ns()`
 --- @return integer
 function vim.api.nvim_buf_set_extmark(buffer, ns_id, line, col, opts) end
 
diff --git a/runtime/lua/vim/_meta/api_keysets.lua b/runtime/lua/vim/_meta/api_keysets.lua
index f7cd92a3b2..2fe5c32faf 100644
--- a/runtime/lua/vim/_meta/api_keysets.lua
+++ b/runtime/lua/vim/_meta/api_keysets.lua
@@ -197,6 +197,9 @@ error('Cannot require a meta file')
 --- @field desc? string
 --- @field replace_keycodes? boolean
 
+--- @class vim.api.keyset.ns_opts
+--- @field wins? any[]
+
 --- @class vim.api.keyset.open_term
 --- @field on_input? function
 --- @field force_crlf? boolean
diff --git a/runtime/lua/vim/highlight.lua b/runtime/lua/vim/highlight.lua
index e972ffaa8c..233bc50237 100644
--- a/runtime/lua/vim/highlight.lua
+++ b/runtime/lua/vim/highlight.lua
@@ -31,8 +31,6 @@ M.priorities = {
 --- Indicates priority of highlight
 --- (default: `vim.highlight.priorities.user`)
 --- @field priority? integer
----
---- @field package _scoped? boolean
 
 --- Apply highlight group to range of text.
 ---
@@ -47,7 +45,6 @@ function M.range(bufnr, ns, higroup, start, finish, opts)
   local regtype = opts.regtype or 'v'
   local inclusive = opts.inclusive or false
   local priority = opts.priority or M.priorities.user
-  local scoped = opts._scoped or false
 
   local v_maxcol = vim.v.maxcol
 
@@ -114,7 +111,6 @@ function M.range(bufnr, ns, higroup, start, finish, opts)
       end_col = end_col,
       priority = priority,
       strict = false,
-      scoped = scoped,
     })
   end
 end
@@ -178,19 +174,18 @@ function M.on_yank(opts)
     yank_cancel()
   end
 
-  vim.api.nvim__win_add_ns(winid, yank_ns)
+  vim.api.nvim__ns_set(yank_ns, { wins = { winid } })
   M.range(bufnr, yank_ns, higroup, "'[", "']", {
     regtype = event.regtype,
     inclusive = event.inclusive,
     priority = opts.priority or M.priorities.user,
-    _scoped = true,
   })
 
   yank_cancel = function()
     yank_timer = nil
     yank_cancel = nil
     pcall(vim.api.nvim_buf_clear_namespace, bufnr, yank_ns, 0, -1)
-    pcall(vim.api.nvim__win_del_ns, winid, yank_ns)
+    pcall(vim.api.nvim__ns_set, { wins = {} })
   end
 
   yank_timer = vim.defer_fn(yank_cancel, timeout)
diff --git a/src/nvim/api/deprecated.c b/src/nvim/api/deprecated.c
index af3bfe2c03..a1af354577 100644
--- a/src/nvim/api/deprecated.c
+++ b/src/nvim/api/deprecated.c
@@ -170,7 +170,7 @@ Integer nvim_buf_set_virtual_text(Buffer buffer, Integer src_id, Integer line, A
   DecorInline decor = { .ext = true, .data.ext.vt = vt, .data.ext.sh_idx = DECOR_ID_INVALID };
 
   extmark_set(buf, ns_id, NULL, (int)line, 0, -1, -1, decor, 0, true,
-              false, false, false, false, NULL);
+              false, false, false, NULL);
   return src_id;
 }
 
diff --git a/src/nvim/api/extmark.c b/src/nvim/api/extmark.c
index 3c8fded2f6..ab6ff5ff1f 100644
--- a/src/nvim/api/extmark.c
+++ b/src/nvim/api/extmark.c
@@ -18,6 +18,7 @@
 #include "nvim/decoration_provider.h"
 #include "nvim/drawscreen.h"
 #include "nvim/extmark.h"
+#include "nvim/globals.h"
 #include "nvim/grid.h"
 #include "nvim/highlight_group.h"
 #include "nvim/map_defs.h"
@@ -41,6 +42,7 @@ void api_extmark_free_all_mem(void)
     xfree(name.data);
   })
   map_destroy(String, &namespace_ids);
+  set_destroy(uint32_t, &namespace_localscope);
 }
 
 /// Creates a new namespace or gets an existing one. [namespace]()
@@ -179,10 +181,6 @@ static Array extmark_to_array(MTPair extmark, bool id, bool add_dict, bool hl_na
       PUT_C(dict, "invalid", BOOLEAN_OBJ(true));
     }
 
-    if (mt_scoped(start)) {
-      PUT_C(dict, "scoped", BOOLEAN_OBJ(true));
-    }
-
     decor_to_dict_legacy(&dict, mt_decor(start), hl_name, arena);
 
     ADD_C(rv, DICTIONARY_OBJ(dict));
@@ -489,8 +487,6 @@ Array nvim_buf_get_extmarks(Buffer buffer, Integer ns_id, Object start, Object e
 ///                   used together with virt_text.
 ///               - url: A URL to associate with this extmark. In the TUI, the OSC 8 control
 ///                   sequence is used to generate a clickable hyperlink to this URL.
-///               - scoped: boolean (EXPERIMENTAL) enables "scoping" for the extmark. See
-///                 |nvim__win_add_ns()|
 ///
 /// @param[out]  err   Error details, if any
 /// @return Id of the created/updated extmark
@@ -749,11 +745,6 @@ Integer nvim_buf_set_extmark(Buffer buffer, Integer ns_id, Integer line, Integer
   }
 
   if (opts->ephemeral && decor_state.win && decor_state.win->w_buffer == buf) {
-    if (opts->scoped) {
-      api_set_error(err, kErrorTypeException, "not yet implemented");
-      goto error;
-    }
-
     int r = (int)line;
     int c = (int)col;
     if (line2 == -1) {
@@ -834,7 +825,7 @@ Integer nvim_buf_set_extmark(Buffer buffer, Integer ns_id, Integer line, Integer
     extmark_set(buf, (uint32_t)ns_id, &id, (int)line, (colnr_T)col, line2, col2,
                 decor, decor_flags, right_gravity, opts->end_right_gravity,
                 !GET_BOOL_OR_TRUE(opts, set_extmark, undo_restore),
-                opts->invalidate, opts->scoped, err);
+                opts->invalidate, err);
     if (ERROR_SET(err)) {
       decor_free(decor);
       return 0;
@@ -960,7 +951,7 @@ Integer nvim_buf_add_highlight(Buffer buffer, Integer ns_id, String hl_group, In
   decor.data.hl.hl_id = hl_id;
 
   extmark_set(buf, ns, NULL, (int)line, (colnr_T)col_start, end_line, (colnr_T)col_end,
-              decor, MT_FLAG_DECOR_HL, true, false, false, false, false, NULL);
+              decor, MT_FLAG_DECOR_HL, true, false, false, false, NULL);
   return ns_id;
 }
 
@@ -1217,77 +1208,119 @@ String nvim__buf_debug_extmarks(Buffer buffer, Boolean keys, Boolean dot, Error
 
 /// EXPERIMENTAL: this API will change in the future.
 ///
-/// Scopes a namespace to the a window, so extmarks in the namespace will be active only in the
-/// given window.
+/// Set some properties for namespace
 ///
-/// @param window Window handle, or 0 for current window
 /// @param ns_id Namespace
-/// @return true if the namespace was added, else false
-Boolean nvim__win_add_ns(Window window, Integer ns_id, Error *err)
+/// @param opts Optional parameters to set:
+///           - wins: a list of windows to be scoped in
+///
+void nvim__ns_set(Integer ns_id, Dict(ns_opts) *opts, Error *err)
 {
-  win_T *win = find_window_by_handle(window, err);
-  if (!win) {
-    return false;
-  }
-
   VALIDATE_INT(ns_initialized((uint32_t)ns_id), "ns_id", ns_id, {
-    return false;
+    return;
   });
 
-  set_put(uint32_t, &win->w_ns_set, (uint32_t)ns_id);
+  bool set_scoped = true;
 
-  if (map_has(uint32_t, win->w_buffer->b_extmark_ns, (uint32_t)ns_id)) {
-    changed_window_setting(win);
-  }
+  if (HAS_KEY(opts, ns_opts, wins)) {
+    if (opts->wins.size == 0) {
+      set_scoped = false;
+    }
 
-  return true;
-}
+    Set(ptr_t) windows = SET_INIT;
+    for (size_t i = 0; i < opts->wins.size; i++) {
+      Integer win = opts->wins.items[i].data.integer;
 
-/// EXPERIMENTAL: this API will change in the future.
-///
-/// Gets the namespace scopes for a given window.
-///
-/// @param window Window handle, or 0 for current window
-/// @return a list of namespaces ids
-ArrayOf(Integer) nvim__win_get_ns(Window window, Arena *arena, Error *err)
-{
-  win_T *win = find_window_by_handle(window, err);
-  if (!win) {
-    return (Array)ARRAY_DICT_INIT;
+      win_T *wp = find_window_by_handle((Window)win, err);
+      if (!wp) {
+        return;
+      }
+
+      set_put(ptr_t, &windows, wp);
+    }
+
+    FOR_ALL_TAB_WINDOWS(tp, wp) {
+      if (set_has(ptr_t, &windows, wp) && !set_has(uint32_t, &wp->w_ns_set, (uint32_t)ns_id)) {
+        set_put(uint32_t, &wp->w_ns_set, (uint32_t)ns_id);
+
+        if (map_has(uint32_t, wp->w_buffer->b_extmark_ns, (uint32_t)ns_id)) {
+          changed_window_setting(wp);
+        }
+      }
+
+      if (set_has(uint32_t, &wp->w_ns_set, (uint32_t)ns_id) && !set_has(ptr_t, &windows, wp)) {
+        set_del(uint32_t, &wp->w_ns_set, (uint32_t)ns_id);
+
+        if (map_has(uint32_t, wp->w_buffer->b_extmark_ns, (uint32_t)ns_id)) {
+          changed_window_setting(wp);
+        }
+      }
+    }
+
+    set_destroy(ptr_t, &windows);
   }
 
-  Array rv = arena_array(arena, set_size(&win->w_ns_set));
-  uint32_t i;
-  set_foreach(&win->w_ns_set, i, {
-    ADD_C(rv, INTEGER_OBJ((Integer)(i)));
-  });
+  if (set_scoped && !set_has(uint32_t, &namespace_localscope, (uint32_t)ns_id)) {
+    set_put(uint32_t, &namespace_localscope, (uint32_t)ns_id);
 
-  return rv;
+    // When a namespace becomes scoped, any window which contains
+    // elements associated with namespace needs to be redrawn
+    FOR_ALL_TAB_WINDOWS(tp, wp) {
+      if (map_has(uint32_t, wp->w_buffer->b_extmark_ns, (uint32_t)ns_id)) {
+        changed_window_setting(wp);
+      }
+    }
+  } else if (!set_scoped && set_has(uint32_t, &namespace_localscope, (uint32_t)ns_id)) {
+    set_del(uint32_t, &namespace_localscope, (uint32_t)ns_id);
+
+    // When a namespace becomes unscoped, any window which does not
+    // contain elements associated with namespace needs to be redrawn
+    FOR_ALL_TAB_WINDOWS(tp, wp) {
+      if (map_has(uint32_t, wp->w_buffer->b_extmark_ns, (uint32_t)ns_id)) {
+        changed_window_setting(wp);
+      }
+    }
+  }
 }
 
 /// EXPERIMENTAL: this API will change in the future.
 ///
-/// Unscopes a namespace (un-binds it from the given scope).
+/// Get the properties for namespace
 ///
-/// @param window Window handle, or 0 for current window
-/// @param ns_id the namespace to remove
-/// @return true if the namespace was removed, else false
-Boolean nvim__win_del_ns(Window window, Integer ns_id, Error *err)
+/// @param ns_id Namespace
+/// @return  Map defining the namespace properties, see |nvim__ns_set()|
+Dict(ns_opts) nvim__ns_get(Integer ns_id, Arena *arena, Error *err)
 {
-  win_T *win = find_window_by_handle(window, err);
-  if (!win) {
-    return false;
+  Dict(ns_opts) opts = KEYDICT_INIT;
+
+  Array windows = ARRAY_DICT_INIT;
+
+  PUT_KEY(opts, ns_opts, wins, windows);
+
+  VALIDATE_INT(ns_initialized((uint32_t)ns_id), "ns_id", ns_id, {
+    return opts;
+  });
+
+  if (!set_has(uint32_t, &namespace_localscope, (uint32_t)ns_id)) {
+    return opts;
   }
 
-  if (!set_has(uint32_t, &win->w_ns_set, (uint32_t)ns_id)) {
-    return false;
+  size_t count = 0;
+  FOR_ALL_TAB_WINDOWS(tp, wp) {
+    if (set_has(uint32_t, &wp->w_ns_set, (uint32_t)ns_id)) {
+      count++;
+    }
   }
 
-  set_del(uint32_t, &win->w_ns_set, (uint32_t)ns_id);
+  windows = arena_array(arena, count);
 
-  if (map_has(uint32_t, win->w_buffer->b_extmark_ns, (uint32_t)ns_id)) {
-    changed_window_setting(win);
+  FOR_ALL_TAB_WINDOWS(tp, wp) {
+    if (set_has(uint32_t, &wp->w_ns_set, (uint32_t)ns_id)) {
+      ADD(windows, INTEGER_OBJ(wp->handle));
+    }
   }
 
-  return true;
+  PUT_KEY(opts, ns_opts, wins, windows);
+
+  return opts;
 }
diff --git a/src/nvim/api/extmark.h b/src/nvim/api/extmark.h
index 124feaabfb..af2d51c95c 100644
--- a/src/nvim/api/extmark.h
+++ b/src/nvim/api/extmark.h
@@ -4,14 +4,29 @@
 
 #include "nvim/api/keysets_defs.h"  // IWYU pragma: keep
 #include "nvim/api/private/defs.h"  // IWYU pragma: keep
+#include "nvim/buffer_defs.h"
 #include "nvim/decoration_defs.h"  // IWYU pragma: keep
 #include "nvim/macros_defs.h"
 #include "nvim/map_defs.h"
 #include "nvim/types_defs.h"
 
 EXTERN Map(String, int) namespace_ids INIT( = MAP_INIT);
+/// Non-global namespaces. A locally-scoped namespace may be "orphaned" if all
+/// window(s) it was scoped to, are destroyed. Such orphans are tracked here to
+/// avoid being mistaken as "global scope".
+EXTERN Set(uint32_t) namespace_localscope INIT( = SET_INIT);
 EXTERN handle_T next_namespace_id INIT( = 1);
 
+/// Returns true if the namespace is global or scoped in the given window.
+static inline bool ns_in_win(uint32_t ns_id, win_T *wp)
+{
+  if (!set_has(uint32_t, &namespace_localscope, ns_id)) {
+    return true;
+  }
+
+  return set_has(uint32_t, &wp->w_ns_set, ns_id);
+}
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "api/extmark.h.generated.h"
 #endif
diff --git a/src/nvim/api/keysets_defs.h b/src/nvim/api/keysets_defs.h
index 00d8aa8428..cc2ef981b5 100644
--- a/src/nvim/api/keysets_defs.h
+++ b/src/nvim/api/keysets_defs.h
@@ -387,3 +387,8 @@ typedef struct {
   Window win;
   Buffer buf;
 } Dict(redraw);
+
+typedef struct {
+  OptionalKeys is_set__ns_opts_;
+  Array wins;
+} Dict(ns_opts);
diff --git a/src/nvim/decoration.c b/src/nvim/decoration.c
index 52a3fa5924..0cf02d96da 100644
--- a/src/nvim/decoration.c
+++ b/src/nvim/decoration.c
@@ -89,7 +89,7 @@ void bufhl_add_hl_pos_offset(buf_T *buf, int src_id, int hl_id, lpos_T pos_start
 
     extmark_set(buf, (uint32_t)src_id, NULL,
                 (int)lnum - 1, hl_start, (int)lnum - 1 + end_off, hl_end,
-                decor, MT_FLAG_DECOR_HL, true, false, true, false, false, NULL);
+                decor, MT_FLAG_DECOR_HL, true, false, true, false, NULL);
   }
 }
 
@@ -598,7 +598,7 @@ int decor_redraw_col(win_T *wp, int col, int win_col, bool hidden, DecorState *s
       break;
     }
 
-    if (!mt_scoped_in_win(mark, wp)) {
+    if (!ns_in_win(mark.ns, wp)) {
       goto next_mark;
     }
 
@@ -747,7 +747,7 @@ void decor_redraw_signs(win_T *wp, buf_T *buf, int row, SignTextAttrs sattrs[],
       break;
     }
     if (!mt_end(mark) && !mt_invalid(mark) && mt_decor_sign(mark)
-        && mt_scoped_in_win(mark, wp)) {
+        && ns_in_win(mark.ns, wp)) {
       DecorSignHighlight *sh = decor_find_sign(mt_decor(mark));
       num_text += (sh->text[0] != NUL);
       kv_push(signs, ((SignItem){ sh, mark.id }));
@@ -927,7 +927,7 @@ int decor_virt_lines(win_T *wp, linenr_T lnum, VirtLines *lines, TriState has_fo
   while (true) {
     MTKey mark = marktree_itr_current(itr);
     DecorVirtText *vt = mt_decor_virt(mark);
-    if (mt_scoped_in_win(mark, wp)) {
+    if (ns_in_win(mark.ns, wp)) {
       while (vt) {
         if (vt->flags & kVTIsLines) {
           bool above = vt->flags & kVTLinesAbove;
diff --git a/src/nvim/extmark.c b/src/nvim/extmark.c
index 4e47fa76fe..b592283d92 100644
--- a/src/nvim/extmark.c
+++ b/src/nvim/extmark.c
@@ -54,12 +54,12 @@
 /// must not be used during iteration!
 void extmark_set(buf_T *buf, uint32_t ns_id, uint32_t *idp, int row, colnr_T col, int end_row,
                  colnr_T end_col, DecorInline decor, uint16_t decor_flags, bool right_gravity,
-                 bool end_right_gravity, bool no_undo, bool invalidate, bool scoped, Error *err)
+                 bool end_right_gravity, bool no_undo, bool invalidate, Error *err)
 {
   uint32_t *ns = map_put_ref(uint32_t, uint32_t)(buf->b_extmark_ns, ns_id, NULL, NULL);
   uint32_t id = idp ? *idp : 0;
 
-  uint16_t flags = mt_flags(right_gravity, no_undo, invalidate, decor.ext, scoped) | decor_flags;
+  uint16_t flags = mt_flags(right_gravity, no_undo, invalidate, decor.ext) | decor_flags;
   if (id == 0) {
     id = ++*ns;
   } else {
diff --git a/src/nvim/marktree.c b/src/nvim/marktree.c
index 34d6cd118f..9e3005b6a3 100644
--- a/src/nvim/marktree.c
+++ b/src/nvim/marktree.c
@@ -2286,7 +2286,7 @@ static void marktree_itr_fix_pos(MarkTree *b, MarkTreeIter *itr)
 void marktree_put_test(MarkTree *b, uint32_t ns, uint32_t id, int row, int col, bool right_gravity,
                        int end_row, int end_col, bool end_right, bool meta_inline)
 {
-  uint16_t flags = mt_flags(right_gravity, false, false, false, false);
+  uint16_t flags = mt_flags(right_gravity, false, false, false);
   // The specific choice is irrelevant here, we pick one counted decor
   // type to test the counting and filtering logic.
   flags |= meta_inline ? MT_FLAG_DECOR_VIRT_TEXT_INLINE : 0;
diff --git a/src/nvim/marktree.h b/src/nvim/marktree.h
index 8e5cf30ff3..15df57ef63 100644
--- a/src/nvim/marktree.h
+++ b/src/nvim/marktree.h
@@ -35,8 +35,6 @@
 #define MT_FLAG_DECOR_VIRT_LINES (((uint16_t)1) << 11)
 #define MT_FLAG_DECOR_VIRT_TEXT_INLINE (((uint16_t)1) << 12)
 
-#define MT_FLAG_SCOPED (((uint16_t)1) << 13)
-
 // These _must_ be last to preserve ordering of marks
 #define MT_FLAG_RIGHT_GRAVITY (((uint16_t)1) << 14)
 #define MT_FLAG_LAST (((uint16_t)1) << 15)
@@ -46,7 +44,7 @@
                              | MT_FLAG_DECOR_VIRT_TEXT_INLINE)
 
 #define MT_FLAG_EXTERNAL_MASK (MT_FLAG_DECOR_MASK | MT_FLAG_NO_UNDO \
-                               | MT_FLAG_INVALIDATE | MT_FLAG_INVALID | MT_FLAG_SCOPED)
+                               | MT_FLAG_INVALIDATE | MT_FLAG_INVALID)
 
 // this is defined so that start and end of the same range have adjacent ids
 #define MARKTREE_END_FLAG ((uint64_t)1)
@@ -110,24 +108,12 @@ static inline bool mt_decor_sign(MTKey key)
   return key.flags & (MT_FLAG_DECOR_SIGNTEXT | MT_FLAG_DECOR_SIGNHL);
 }
 
-static inline bool mt_scoped(MTKey key)
-{
-  return key.flags & MT_FLAG_SCOPED;
-}
-
-static inline bool mt_scoped_in_win(MTKey key, win_T *wp)
-{
-  return !mt_scoped(key) || set_has(uint32_t, &wp->w_ns_set, key.ns);
-}
-
-static inline uint16_t mt_flags(bool right_gravity, bool no_undo, bool invalidate, bool decor_ext,
-                                bool scoped)
+static inline uint16_t mt_flags(bool right_gravity, bool no_undo, bool invalidate, bool decor_ext)
 {
   return (uint16_t)((right_gravity ? MT_FLAG_RIGHT_GRAVITY : 0)
                     | (no_undo ? MT_FLAG_NO_UNDO : 0)
                     | (invalidate ? MT_FLAG_INVALIDATE : 0)
-                    | (decor_ext ? MT_FLAG_DECOR_EXT : 0)
-                    | (scoped ? MT_FLAG_SCOPED : 0));
+                    | (decor_ext ? MT_FLAG_DECOR_EXT : 0));
 }
 
 static inline MTPair mtpair_from(MTKey start, MTKey end)
diff --git a/src/nvim/plines.c b/src/nvim/plines.c
index 5881d34c48..f273f88dd1 100644
--- a/src/nvim/plines.c
+++ b/src/nvim/plines.c
@@ -5,6 +5,7 @@
 #include <stdint.h>
 #include <string.h>
 
+#include "nvim/api/extmark.h"
 #include "nvim/ascii_defs.h"
 #include "nvim/buffer.h"
 #include "nvim/buffer_defs.h"
@@ -158,7 +159,7 @@ CharSize charsize_regular(CharsizeArg *csarg, char *const cur, colnr_T const vco
         break;
       } else if (mark.pos.col == col) {
         if (!mt_end(mark) && (mark.flags & MT_FLAG_DECOR_VIRT_TEXT_INLINE)
-            && mt_scoped_in_win(mark, wp)) {
+            && ns_in_win(mark.ns, wp)) {
           DecorInline decor = mt_decor(mark);
           DecorVirtText *vt = decor.ext ? decor.data.ext.vt : NULL;
           while (vt) {
diff --git a/src/nvim/sign.c b/src/nvim/sign.c
index 496913f9bf..1ca0e846a9 100644
--- a/src/nvim/sign.c
+++ b/src/nvim/sign.c
@@ -127,7 +127,7 @@ static void buf_set_sign(buf_T *buf, uint32_t *id, char *group, int prio, linenr
 
   DecorInline decor = { .ext = true, .data.ext = { .vt = NULL, .sh_idx = decor_put_sh(sign) } };
   extmark_set(buf, ns, id, lnum - 1, 0, -1, -1, decor, decor_flags, true,
-              false, true, true, false, NULL);
+              false, true, true, NULL);
 }
 
 /// For an existing, placed sign with "id", modify the sign, group or priority.
diff --git a/test/functional/lua/highlight_spec.lua b/test/functional/lua/highlight_spec.lua
index 66095121b0..ad709a06f1 100644
--- a/test/functional/lua/highlight_spec.lua
+++ b/test/functional/lua/highlight_spec.lua
@@ -4,7 +4,6 @@ local Screen = require('test.functional.ui.screen')
 
 local exec_lua = n.exec_lua
 local eq = t.eq
-local neq = t.neq
 local eval = n.eval
 local command = n.command
 local clear = n.clear
@@ -142,9 +141,11 @@ describe('vim.highlight.on_yank', function()
       vim.api.nvim_buf_set_mark(0,"]",1,1,{})
       vim.highlight.on_yank({timeout = math.huge, on_macro = true, event = {operator = "y"}})
     ]])
-    neq({}, api.nvim__win_get_ns(0))
+    local ns = api.nvim_create_namespace('hlyank')
+    local win = api.nvim_get_current_win()
+    eq({ win }, api.nvim__ns_get(ns).wins)
     command('wincmd w')
-    eq({}, api.nvim__win_get_ns(0))
+    eq({ win }, api.nvim__ns_get(ns).wins)
   end)
 
   it('removes old highlight if new one is created before old one times out', function()
@@ -154,14 +155,17 @@ describe('vim.highlight.on_yank', function()
       vim.api.nvim_buf_set_mark(0,"]",1,1,{})
       vim.highlight.on_yank({timeout = math.huge, on_macro = true, event = {operator = "y"}})
     ]])
-    neq({}, api.nvim__win_get_ns(0))
+    local ns = api.nvim_create_namespace('hlyank')
+    eq(api.nvim_get_current_win(), api.nvim__ns_get(ns).wins[1])
     command('wincmd w')
     exec_lua([[
       vim.api.nvim_buf_set_mark(0,"[",1,1,{})
       vim.api.nvim_buf_set_mark(0,"]",1,1,{})
       vim.highlight.on_yank({timeout = math.huge, on_macro = true, event = {operator = "y"}})
     ]])
+    local win = api.nvim_get_current_win()
+    eq({ win }, api.nvim__ns_get(ns).wins)
     command('wincmd w')
-    eq({}, api.nvim__win_get_ns(0))
+    eq({ win }, api.nvim__ns_get(ns).wins)
   end)
 end)
diff --git a/test/functional/ui/decorations_spec.lua b/test/functional/ui/decorations_spec.lua
index 3e67e33ddb..318dc8c197 100644
--- a/test/functional/ui/decorations_spec.lua
+++ b/test/functional/ui/decorations_spec.lua
@@ -5595,20 +5595,26 @@ describe('decorations: virt_text', function()
 end)
 
 describe('decorations: window scoped', function()
-  local screen, ns
+  local screen, ns, win_other
   local url = 'https://example.com'
   before_each(function()
     clear()
     screen = Screen.new(20, 10)
     screen:attach()
     screen:add_extra_attr_ids {
-        [100] = { special = Screen.colors.Red, undercurl = true },
-        [101] = { url = "https://example.com" },
+      [100] = { special = Screen.colors.Red, undercurl = true },
+      [101] = { url = 'https://example.com' },
     }
 
     ns = api.nvim_create_namespace 'test'
 
     insert('12345')
+
+    win_other = api.nvim_open_win(0, false, {
+      col=0,row=0,width=20,height=10,
+      relative = 'win',style = 'minimal',
+      hide = true
+    })
   end)
 
   local noextmarks = {
@@ -5616,28 +5622,28 @@ describe('decorations: window scoped', function()
       1234^5               |
       {1:~                   }|*8
                           |
-    ]]}
+    ]],
+  }
 
-  local function set_scoped_extmark(line, col, opts)
-    return api.nvim_buf_set_extmark(0, ns, line, col, vim.tbl_extend('error', { scoped = true }, opts))
+  local function set_extmark(line, col, opts)
+    return api.nvim_buf_set_extmark(0, ns, line, col, opts)
   end
 
   it('hl_group', function()
-    set_scoped_extmark(0, 0, {
+    set_extmark(0, 0, {
       hl_group = 'Comment',
       end_col = 3,
     })
 
-    screen:expect(noextmarks)
-
-    api.nvim__win_add_ns(0, ns)
+    api.nvim__ns_set(ns, { wins = { 0 } })
 
     screen:expect {
       grid = [[
       {18:123}4^5               |
       {1:~                   }|*8
                           |
-    ]]}
+    ]],
+    }
 
     command 'split'
     command 'only'
@@ -5646,48 +5652,55 @@ describe('decorations: window scoped', function()
   end)
 
   it('virt_text', function()
-    set_scoped_extmark(0, 0, {
+    set_extmark(0, 0, {
       virt_text = { { 'a', 'Comment' } },
       virt_text_pos = 'eol',
     })
-    set_scoped_extmark(0, 5, {
+    set_extmark(0, 5, {
       virt_text = { { 'b', 'Comment' } },
       virt_text_pos = 'inline',
     })
-    set_scoped_extmark(0, 1, {
+    set_extmark(0, 1, {
       virt_text = { { 'c', 'Comment' } },
       virt_text_pos = 'overlay',
     })
-    set_scoped_extmark(0, 1, {
+    set_extmark(0, 1, {
       virt_text = { { 'd', 'Comment' } },
       virt_text_pos = 'right_align',
     })
 
-    screen:expect(noextmarks)
-
-    api.nvim__win_add_ns(0, ns)
+    api.nvim__ns_set(ns, { wins = { 0 } })
 
     screen:expect {
       grid = [[
       1{18:c}34^5{18:b} {18:a}           {18:d}|
       {1:~                   }|*8
                           |
-    ]]}
+    ]],
+    }
 
     command 'split'
     command 'only'
 
     screen:expect(noextmarks)
+
+    api.nvim__ns_set(ns, { wins = {} })
+
+    screen:expect {
+      grid = [[
+      1{18:c}34^5{18:b} {18:a}           {18:d}|
+      {1:~                   }|*8
+                          |
+    ]],
+    }
   end)
 
   it('virt_lines', function()
-    set_scoped_extmark(0, 0, {
+    set_extmark(0, 0, {
       virt_lines = { { { 'a', 'Comment' } } },
     })
 
-    screen:expect(noextmarks)
-
-    api.nvim__win_add_ns(0, ns)
+    api.nvim__ns_set(ns, { wins = { 0 } })
 
     screen:expect {
       grid = [[
@@ -5695,7 +5708,8 @@ describe('decorations: window scoped', function()
       {18:a}                   |
       {1:~                   }|*7
                           |
-    ]]}
+    ]],
+    }
 
     command 'split'
     command 'only'
@@ -5704,14 +5718,12 @@ describe('decorations: window scoped', function()
   end)
 
   it('redraws correctly with inline virt_text and wrapping', function()
-    set_scoped_extmark(0, 2, {
-      virt_text = {{ ('b'):rep(18), 'Comment' }},
-      virt_text_pos = 'inline'
+    set_extmark(0, 2, {
+      virt_text = { { ('b'):rep(18), 'Comment' } },
+      virt_text_pos = 'inline',
     })
 
-    screen:expect(noextmarks)
-
-    api.nvim__win_add_ns(0, ns)
+    api.nvim__ns_set(ns, { wins = { 0 } })
 
     screen:expect {
       grid = [[
@@ -5719,9 +5731,10 @@ describe('decorations: window scoped', function()
       34^5                 |
       {1:~                   }|*7
                           |
-    ]]}
+    ]],
+    }
 
-    api.nvim__win_del_ns(0, ns)
+    api.nvim__ns_set(ns, { wins = { win_other } })
 
     screen:expect(noextmarks)
   end)
@@ -5729,21 +5742,20 @@ describe('decorations: window scoped', function()
   pending('sign_text', function()
     -- TODO(altermo): The window signcolumn width is calculated wrongly (when `signcolumn=auto`)
     -- This happens in function `win_redraw_signcols` on line containing `buf_meta_total(buf, kMTMetaSignText) > 0`
-    set_scoped_extmark(0, 0, {
+    set_extmark(0, 0, {
       sign_text = 'a',
       sign_hl_group = 'Comment',
     })
 
-    screen:expect(noextmarks)
-
-    api.nvim__win_add_ns(0, ns)
+    api.nvim__ns_set(ns, { wins = { 0 } })
 
     screen:expect {
       grid = [[
       a 1234^5             |
       {2:~                   }|*8
                           |
-    ]]}
+    ]],
+    }
 
     command 'split'
     command 'only'
@@ -5752,30 +5764,34 @@ describe('decorations: window scoped', function()
   end)
 
   it('statuscolumn hl group', function()
-    set_scoped_extmark(0, 0, {
-      number_hl_group='comment',
+    set_extmark(0, 0, {
+      number_hl_group = 'comment',
     })
-    set_scoped_extmark(0, 0, {
-      line_hl_group='comment',
+    set_extmark(0, 0, {
+      line_hl_group = 'comment',
     })
 
     command 'set number'
 
+    api.nvim__ns_set(ns, { wins = { win_other } })
+
     screen:expect {
       grid = [[
       {8:  1 }1234^5           |
       {1:~                   }|*8
                           |
-    ]]}
+    ]],
+    }
 
-    api.nvim__win_add_ns(0, ns)
+    api.nvim__ns_set(ns, { wins = { 0 } })
 
     screen:expect {
       grid = [[
       {18:  1 1234^5           }|
       {1:~                   }|*8
                           |
-    ]]}
+    ]],
+    }
 
     command 'split'
     command 'only'
@@ -5785,36 +5801,43 @@ describe('decorations: window scoped', function()
       {8:  1 }1234^5           |
       {1:~                   }|*8
                           |
-    ]]}
+    ]],
+    }
   end)
 
   it('spell', function()
-    api.nvim_buf_set_lines(0,0,-1,true,{'aa'})
+    api.nvim_buf_set_lines(0, 0, -1, true, { 'aa' })
 
-    set_scoped_extmark(0, 0, {
-      spell=true,
-      end_col=2,
+    set_extmark(0, 0, {
+      spell = true,
+      end_col = 2,
     })
 
     command 'set spelloptions=noplainbuffer'
     command 'set spell'
     command 'syntax off'
 
+    screen:expect({ unchanged = true })
+
+    api.nvim__ns_set(ns, { wins = { win_other } })
+
     screen:expect {
       grid = [[
       a^a                  |
       {1:~                   }|*8
                           |
-    ]]}
+    ]],
+    }
 
-    api.nvim__win_add_ns(0, ns)
+    api.nvim__ns_set(ns, { wins = { 0 } })
 
     screen:expect {
       grid = [[
       {100:a^a}                  |
       {1:~                   }|*8
                           |
-    ]]}
+    ]],
+    }
 
     command 'split'
     command 'only'
@@ -5824,25 +5847,25 @@ describe('decorations: window scoped', function()
       a^a                  |
       {1:~                   }|*8
                           |
-    ]]}
+    ]],
+    }
   end)
 
   it('url', function()
-    set_scoped_extmark(0, 0, {
-      end_col=3,
-      url=url,
+    set_extmark(0, 0, {
+      end_col = 3,
+      url = url,
     })
 
-    screen:expect(noextmarks)
-
-    api.nvim__win_add_ns(0, ns)
+    api.nvim__ns_set(ns, { wins = { 0 } })
 
     screen:expect {
       grid = [[
       {101:123}4^5               |
       {1:~                   }|*8
                           |
-    ]]}
+    ]],
+    }
 
     command 'split'
     command 'only'
@@ -5850,85 +5873,72 @@ describe('decorations: window scoped', function()
     screen:expect(noextmarks)
   end)
 
-  it('change extmarks scoped option', function()
-    local id = set_scoped_extmark(0, 0, {
+  it('change namespace scope', function()
+    set_extmark(0, 0, {
       hl_group = 'Comment',
       end_col = 3,
     })
 
-    api.nvim__win_add_ns(0, ns)
+    api.nvim__ns_set(ns, { wins = { 0 } })
+    eq({ wins={ api.nvim_get_current_win() } }, api.nvim__ns_get(ns))
 
     screen:expect {
       grid = [[
       {18:123}4^5               |
       {1:~                   }|*8
                           |
-    ]]}
+    ]],
+    }
 
     command 'split'
     command 'only'
 
     screen:expect(noextmarks)
 
-    api.nvim_buf_set_extmark(0, ns, 0, 0, {
-      id = id,
-      hl_group = 'Comment',
-      end_col = 3,
-      scoped = false,
-    })
+    api.nvim__ns_set(ns, { wins = { 0 } })
+    eq({ wins={ api.nvim_get_current_win() } }, api.nvim__ns_get(ns))
 
     screen:expect {
       grid = [[
       {18:123}4^5               |
       {1:~                   }|*8
                           |
-    ]]}
+    ]],
+    }
 
-    api.nvim_buf_set_extmark(0, ns, 0, 0, {
-      id = id,
-      hl_group = 'Comment',
-      end_col = 3,
-      scoped = true,
+    local win_new = api.nvim_open_win(0, false, {
+      col=0,row=0,width=20,height=10,
+      relative = 'win',style = 'minimal',
+      hide = true
     })
 
+    api.nvim__ns_set(ns, { wins = { win_new } })
+    eq({ wins={ win_new } }, api.nvim__ns_get(ns))
+
     screen:expect(noextmarks)
   end)
 
-  it('change namespace scope', function()
-    set_scoped_extmark(0, 0, {
-      hl_group = 'Comment',
-      end_col = 3,
-    })
+  it('namespace get works', function()
+    eq({ wins = {} }, api.nvim__ns_get(ns))
 
-    eq(true, api.nvim__win_add_ns(0, ns))
-    eq({ ns }, api.nvim__win_get_ns(0))
+    api.nvim__ns_set(ns, { wins = { 0 } })
 
-    screen:expect {
-      grid = [[
-      {18:123}4^5               |
-      {1:~                   }|*8
-                          |
-    ]]}
+    eq({ wins = { api.nvim_get_current_win() } }, api.nvim__ns_get(ns))
 
-    command 'split'
-    command 'only'
-    eq({}, api.nvim__win_get_ns(0))
+    api.nvim__ns_set(ns, { wins = {} })
 
-    screen:expect(noextmarks)
+    eq({ wins = {} }, api.nvim__ns_get(ns))
+  end)
 
-    eq(true, api.nvim__win_add_ns(0, ns))
-    eq({ ns }, api.nvim__win_get_ns(0))
+  it('remove window from namespace scope when deleted', function ()
+    api.nvim__ns_set(ns, { wins = { 0 } })
 
-    screen:expect {
-      grid = [[
-      {18:123}4^5               |
-      {1:~                   }|*8
-                          |
-    ]]}
+    eq({ wins = { api.nvim_get_current_win() } }, api.nvim__ns_get(ns))
 
-    eq(true, api.nvim__win_del_ns(0, ns))
-    eq({}, api.nvim__win_get_ns(0))
+    command 'split'
+    command 'only'
 
-    screen:expect(noextmarks)
+    eq({ wins = {} }, api.nvim__ns_get(ns))
   end)
 end)
+