Merge remote-tracking branch 'upstream/master' into usermarksusermarks

1 files changed, 1200 insertions, 1220 deletions

diff --git a/src/nvim/window.c b/src/nvim/window.c
index 68c5b42e30..05f84b5a91 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -2,21 +2,34 @@
 // it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
 
 #include <assert.h>
+#include <ctype.h>
 #include <inttypes.h>
+#include <limits.h>
 #include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
+#include "klib/kvec.h"
+#include "nvim/api/private/defs.h"
 #include "nvim/api/private/helpers.h"
-#include "nvim/api/vim.h"
 #include "nvim/arglist.h"
 #include "nvim/ascii.h"
+#include "nvim/autocmd.h"
 #include "nvim/buffer.h"
+#include "nvim/buffer_defs.h"
 #include "nvim/charset.h"
 #include "nvim/cursor.h"
+#include "nvim/decoration.h"
 #include "nvim/diff.h"
 #include "nvim/drawscreen.h"
 #include "nvim/edit.h"
 #include "nvim/eval.h"
+#include "nvim/eval/typval.h"
+#include "nvim/eval/typval_defs.h"
 #include "nvim/eval/vars.h"
+#include "nvim/eval/window.h"
 #include "nvim/ex_cmds.h"
 #include "nvim/ex_cmds2.h"
 #include "nvim/ex_docmd.h"
@@ -27,15 +40,19 @@
 #include "nvim/fold.h"
 #include "nvim/garray.h"
 #include "nvim/getchar.h"
+#include "nvim/gettext.h"
 #include "nvim/globals.h"
 #include "nvim/grid.h"
 #include "nvim/hashtab.h"
-#include "nvim/highlight.h"
+#include "nvim/keycodes.h"
+#include "nvim/macros.h"
 #include "nvim/main.h"
-#include "nvim/mapping.h"
+#include "nvim/map.h"
+#include "nvim/mapping.h"  // IWYU pragma: keep (langmap_adjust_mb)
 #include "nvim/mark.h"
 #include "nvim/match.h"
-#include "nvim/memline.h"
+#include "nvim/mbyte.h"
+#include "nvim/memline_defs.h"
 #include "nvim/memory.h"
 #include "nvim/message.h"
 #include "nvim/mouse.h"
@@ -44,16 +61,19 @@
 #include "nvim/option.h"
 #include "nvim/optionstr.h"
 #include "nvim/os/os.h"
-#include "nvim/os_unix.h"
+#include "nvim/os/os_defs.h"
 #include "nvim/path.h"
 #include "nvim/plines.h"
+#include "nvim/pos.h"
 #include "nvim/quickfix.h"
-#include "nvim/regexp.h"
+#include "nvim/screen.h"
 #include "nvim/search.h"
 #include "nvim/state.h"
+#include "nvim/statusline.h"
 #include "nvim/strings.h"
 #include "nvim/syntax.h"
 #include "nvim/terminal.h"
+#include "nvim/types.h"
 #include "nvim/ui.h"
 #include "nvim/ui_compositor.h"
 #include "nvim/undo.h"
@@ -125,15 +145,10 @@ win_T *prevwin_curwin(void)
 /// @param xchar  extra char from ":wincmd gx" or NUL
 void do_window(int nchar, long Prenum, int xchar)
 {
-  long Prenum1;
-  win_T *wp;
-  char *ptr;
-  linenr_T lnum = -1;
   int type = FIND_DEFINE;
-  size_t len;
   char cbuf[40];
 
-  Prenum1 = Prenum == 0 ? 1 : Prenum;
+  long Prenum1 = Prenum == 0 ? 1 : Prenum;
 
 #define CHECK_CMDWIN \
   do { \
@@ -215,7 +230,7 @@ newwindow:
   case Ctrl_Q:
   case 'q':
     reset_VIsual_and_resel();                   // stop Visual mode
-    cmd_with_count("quit", (char_u *)cbuf, sizeof(cbuf), Prenum);
+    cmd_with_count("quit", cbuf, sizeof(cbuf), Prenum);
     do_cmdline_cmd(cbuf);
     break;
 
@@ -223,7 +238,7 @@ newwindow:
   case Ctrl_C:
   case 'c':
     reset_VIsual_and_resel();                   // stop Visual mode
-    cmd_with_count("close", (char_u *)cbuf, sizeof(cbuf), Prenum);
+    cmd_with_count("close", cbuf, sizeof(cbuf), Prenum);
     do_cmdline_cmd(cbuf);
     break;
 
@@ -236,8 +251,8 @@ newwindow:
     break;
 
   // cursor to preview window
-  case 'P':
-    wp = NULL;
+  case 'P': {
+    win_T *wp = NULL;
     FOR_ALL_WINDOWS_IN_TAB(wp2, curtab) {
       if (wp2->w_p_pvw) {
         wp = wp2;
@@ -250,13 +265,14 @@ newwindow:
       win_goto(wp);
     }
     break;
+  }
 
   // close all but current window
   case Ctrl_O:
   case 'o':
     CHECK_CMDWIN;
     reset_VIsual_and_resel();  // stop Visual mode
-    cmd_with_count("only", (char_u *)cbuf, sizeof(cbuf), Prenum);
+    cmd_with_count("only", cbuf, sizeof(cbuf), Prenum);
     do_cmdline_cmd(cbuf);
     break;
 
@@ -269,13 +285,13 @@ newwindow:
     if (ONE_WINDOW && Prenum != 1) {  // just one window
       beep_flush();
     } else {
+      win_T *wp;
       if (Prenum) {  // go to specified window
         for (wp = firstwin; --Prenum > 0;) {
           if (wp->w_next == NULL) {
             break;
-          } else {
-            wp = wp->w_next;
           }
+          wp = wp->w_next;
         }
       } else {
         if (nchar == 'W') {  // go to previous window
@@ -346,7 +362,7 @@ newwindow:
 
       // First create a new tab with the window, then go back to
       // the old tab and close the window there.
-      wp = curwin;
+      win_T *wp = curwin;
       if (win_new_tabpage((int)Prenum, NULL) == OK
           && valid_tabpage(oldtab)) {
         newtab = curtab;
@@ -417,10 +433,12 @@ newwindow:
               | ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
     break;
 
-  // make all windows the same height
-  case '=':
-    win_equal(NULL, false, 'b');
+  // make all windows the same width and/or height
+  case '=': {
+    int mod = cmdmod.cmod_split & (WSP_VERT | WSP_HOR);
+    win_equal(NULL, false, mod == WSP_VERT ? 'v' : mod == WSP_HOR ? 'h' : 'b');
     break;
+  }
 
   // increase current window height
   case '+':
@@ -479,16 +497,18 @@ newwindow:
     // Execute the command right here, required when
     // "wincmd ]" was used in a function.
     do_nv_ident(Ctrl_RSB, NUL);
+    postponed_split = 0;
     break;
 
   // edit file name under cursor in a new window
   case 'f':
   case 'F':
-  case Ctrl_F:
+  case Ctrl_F: {
 wingotofile:
     CHECK_CMDWIN;
 
-    ptr = (char *)grab_file_name(Prenum1, &lnum);
+    linenr_T lnum = -1;
+    char *ptr = grab_file_name(Prenum1, &lnum);
     if (ptr != NULL) {
       tabpage_T *oldtab = curtab;
       win_T *oldwin = curwin;
@@ -508,6 +528,7 @@ wingotofile:
       xfree(ptr);
     }
     break;
+  }
 
   // Go to the first occurrence of the identifier under cursor along path in a
   // new window -- webb
@@ -516,8 +537,10 @@ wingotofile:
     type = FIND_ANY;
     FALLTHROUGH;
   case 'd':                         // Go to definition, using 'define'
-  case Ctrl_D:
+  case Ctrl_D: {
     CHECK_CMDWIN;
+    size_t len;
+    char *ptr;
     if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0) {
       break;
     }
@@ -525,11 +548,12 @@ wingotofile:
     // Make a copy, if the line was changed it will be freed.
     ptr = xstrnsave(ptr, len);
 
-    find_pattern_in_path((char_u *)ptr, 0, len, true, Prenum == 0,
+    find_pattern_in_path(ptr, 0, len, true, Prenum == 0,
                          type, Prenum1, ACTION_SPLIT, 1, MAXLNUM);
     xfree(ptr);
     curwin->w_set_curswant = true;
     break;
+  }
 
   // Quickfix window only: view the result under the cursor in a new split.
   case K_KENTER:
@@ -552,6 +576,7 @@ wingotofile:
     no_mapping--;
     allow_keys--;
     (void)add_to_showcmd(xchar);
+
     switch (xchar) {
     case '}':
       xchar = Ctrl_RSB;
@@ -573,6 +598,7 @@ wingotofile:
       // Execute the command right here, required when
       // "wincmd g}" was used in a function.
       do_nv_ident('g', xchar);
+      postponed_split = 0;
       break;
 
     case 'f':                       // CTRL-W gf: "gf" in a new tab page
@@ -580,6 +606,7 @@ wingotofile:
       cmdmod.cmod_tab = tabpage_index(curtab) + 1;
       nchar = xchar;
       goto wingotofile;
+
     case 't':                       // CTRL-W gt: go to next tab page
       goto_tabpage((int)Prenum);
       break;
@@ -622,12 +649,12 @@ wingotofile:
   }
 }
 
-static void cmd_with_count(char *cmd, char_u *bufp, size_t bufsize, int64_t Prenum)
+static void cmd_with_count(char *cmd, char *bufp, size_t bufsize, int64_t Prenum)
 {
-  size_t len = STRLCPY(bufp, cmd, bufsize);
+  size_t len = xstrlcpy(bufp, cmd, bufsize);
 
   if (Prenum > 0 && len < bufsize) {
-    vim_snprintf((char *)bufp + len, bufsize - len, "%" PRId64, Prenum);
+    vim_snprintf(bufp + len, bufsize - len, "%" PRId64, Prenum);
   }
 }
 
@@ -635,11 +662,13 @@ void win_set_buf(Window window, Buffer buffer, bool noautocmd, Error *err)
 {
   win_T *win = find_window_by_handle(window, err);
   buf_T *buf = find_buffer_by_handle(buffer, err);
-  tabpage_T *tab = win_find_tabpage(win);
 
   if (!win || !buf) {
     return;
   }
+
+  tabpage_T *tab = win_find_tabpage(win);
+
   if (noautocmd) {
     block_autocmds();
   }
@@ -712,7 +741,7 @@ win_T *win_new_float(win_T *wp, bool last, FloatConfig fconfig, Error *err)
   win_config_float(wp, fconfig);
   win_set_inner_size(wp, true);
   wp->w_pos_changed = true;
-  redraw_later(wp, VALID);
+  redraw_later(wp, UPD_VALID);
   return wp;
 }
 
@@ -727,38 +756,44 @@ void win_set_minimal_style(win_T *wp)
 
   // Hide EOB region: use " " fillchar and cleared highlighting
   if (wp->w_p_fcs_chars.eob != ' ') {
-    char_u *old = wp->w_p_fcs;
+    char *old = wp->w_p_fcs;
     wp->w_p_fcs = ((*old == NUL)
-                   ? (char_u *)xstrdup("eob: ")
-                   : concat_str(old, (char_u *)",eob: "));
+                   ? xstrdup("eob: ")
+                   : concat_str(old, ",eob: "));
     free_string_option(old);
   }
 
   // TODO(bfredl): this could use a highlight namespace directly,
-  // and avoid pecularities around window options
-  char_u *old = wp->w_p_winhl;
+  // and avoid peculiarities around window options
+  char *old = wp->w_p_winhl;
   wp->w_p_winhl = ((*old == NUL)
-                   ? (char_u *)xstrdup("EndOfBuffer:")
-                   : concat_str(old, (char_u *)",EndOfBuffer:"));
+                   ? xstrdup("EndOfBuffer:")
+                   : concat_str(old, ",EndOfBuffer:"));
   free_string_option(old);
   parse_winhl_opt(wp);
 
   // signcolumn: use 'auto'
-  if (wp->w_p_scl[0] != 'a' || STRLEN(wp->w_p_scl) >= 8) {
+  if (wp->w_p_scl[0] != 'a' || strlen(wp->w_p_scl) >= 8) {
     free_string_option(wp->w_p_scl);
-    wp->w_p_scl = (char_u *)xstrdup("auto");
+    wp->w_p_scl = xstrdup("auto");
   }
 
   // foldcolumn: use '0'
   if (wp->w_p_fdc[0] != '0') {
     free_string_option(wp->w_p_fdc);
-    wp->w_p_fdc = (char_u *)xstrdup("0");
+    wp->w_p_fdc = xstrdup("0");
   }
 
   // colorcolumn: cleared
   if (wp->w_p_cc != NULL && *wp->w_p_cc != NUL) {
     free_string_option(wp->w_p_cc);
-    wp->w_p_cc = (char_u *)xstrdup("");
+    wp->w_p_cc = xstrdup("");
+  }
+
+  // statuscolumn: cleared
+  if (wp->w_p_stc != NULL && *wp->w_p_stc != NUL) {
+    free_string_option(wp->w_p_stc);
+    wp->w_p_stc = xstrdup("");
   }
 }
 
@@ -772,13 +807,22 @@ void win_config_float(win_T *wp, FloatConfig fconfig)
     fconfig.row += curwin->w_wrow;
     fconfig.col += curwin->w_wcol;
     fconfig.window = curwin->handle;
+  } else if (fconfig.relative == kFloatRelativeMouse) {
+    int row = mouse_row, col = mouse_col, grid = mouse_grid;
+    win_T *mouse_win = mouse_find_win(&grid, &row, &col);
+    if (mouse_win != NULL) {
+      fconfig.relative = kFloatRelativeWindow;
+      fconfig.row += row;
+      fconfig.col += col;
+      fconfig.window = mouse_win->handle;
+    }
   }
 
   bool change_external = fconfig.external != wp->w_float_config.external;
   bool change_border = (fconfig.border != wp->w_float_config.border
                         || memcmp(fconfig.border_hl_ids,
                                   wp->w_float_config.border_hl_ids,
-                                  sizeof fconfig.border_hl_ids));
+                                  sizeof fconfig.border_hl_ids) != 0);
 
   wp->w_float_config = fconfig;
 
@@ -797,12 +841,12 @@ void win_config_float(win_T *wp, FloatConfig fconfig)
   }
 
   win_set_inner_size(wp, true);
-  must_redraw = MAX(must_redraw, VALID);
+  must_redraw = MAX(must_redraw, UPD_VALID);
 
   wp->w_pos_changed = true;
   if (change_external || change_border) {
     wp->w_hl_needs_update = true;
-    redraw_later(wp, NOT_VALID);
+    redraw_later(wp, UPD_NOT_VALID);
   }
 
   // compute initial position
@@ -819,16 +863,16 @@ void win_config_float(win_T *wp, FloatConfig fconfig)
       grid_adjust(&grid, &row_off, &col_off);
       row += row_off;
       col += col_off;
+      if (wp->w_float_config.bufpos.lnum >= 0) {
+        pos_T pos = { wp->w_float_config.bufpos.lnum + 1,
+                      wp->w_float_config.bufpos.col, 0 };
+        int trow, tcol, tcolc, tcole;
+        textpos2screenpos(parent, &pos, &trow, &tcol, &tcolc, &tcole, true);
+        row += trow - 1;
+        col += tcol - 1;
+      }
     }
     api_clear_error(&dummy);
-    if (wp->w_float_config.bufpos.lnum >= 0) {
-      pos_T pos = { wp->w_float_config.bufpos.lnum + 1,
-                    wp->w_float_config.bufpos.col, 0 };
-      int trow, tcol, tcolc, tcole;
-      textpos2screenpos(wp, &pos, &trow, &tcol, &tcolc, &tcole, true);
-      row += trow - 1;
-      col += tcol - 1;
-    }
     wp->w_winrow = row;
     wp->w_wincol = col;
   } else {
@@ -839,7 +883,7 @@ void win_config_float(win_T *wp, FloatConfig fconfig)
   // changing border style while keeping border only requires redrawing border
   if (fconfig.border) {
     wp->w_redr_border = true;
-    redraw_later(wp, VALID);
+    redraw_later(wp, UPD_VALID);
   }
 }
 
@@ -864,13 +908,13 @@ int win_fdccol_count(win_T *wp)
     const int fdccol = fdc[4] == ':' ? fdc[5] - '0' : 1;
     int needed_fdccols = getDeepestNesting(wp);
     return MIN(fdccol, needed_fdccols);
-  } else {
-    return fdc[0] - '0';
   }
+  return fdc[0] - '0';
 }
 
-void ui_ext_win_position(win_T *wp)
+void ui_ext_win_position(win_T *wp, bool validate)
 {
+  wp->w_pos_changed = false;
   if (!wp->w_floating) {
     ui_call_win_pos(wp->w_grid_alloc.handle, wp->handle, wp->w_winrow,
                     wp->w_wincol, wp->w_width, wp->w_height);
@@ -908,6 +952,11 @@ void ui_ext_win_position(win_T *wp)
                             grid->handle, row, col, c.focusable,
                             wp->w_grid_alloc.zindex);
     } else {
+      bool valid = (wp->w_redr_type == 0);
+      if (!valid && !validate) {
+        wp->w_pos_changed = true;
+        return;
+      }
       // TODO(bfredl): ideally, compositor should work like any multigrid UI
       // and use standard win_pos events.
       bool east = c.anchor & kFloatAnchorEast;
@@ -921,14 +970,13 @@ void ui_ext_win_position(win_T *wp)
       comp_col = MAX(MIN(comp_col, Columns - wp->w_width_outer), 0);
       wp->w_winrow = comp_row;
       wp->w_wincol = comp_col;
-      bool valid = (wp->w_redr_type == 0);
       ui_comp_put_grid(&wp->w_grid_alloc, comp_row, comp_col,
                        wp->w_height_outer, wp->w_width_outer, valid, false);
       ui_check_cursor_grid(wp->w_grid_alloc.handle);
       wp->w_grid_alloc.focusable = wp->w_float_config.focusable;
       if (!valid) {
         wp->w_grid_alloc.valid = false;
-        redraw_later(wp, NOT_VALID);
+        redraw_later(wp, UPD_NOT_VALID);
       }
     }
   } else {
@@ -968,21 +1016,19 @@ static int check_split_disallowed(void)
   return OK;
 }
 
-/*
- * split the current window, implements CTRL-W s and :split
- *
- * "size" is the height or width for the new window, 0 to use half of current
- * height or width.
- *
- * "flags":
- * WSP_ROOM: require enough room for new window
- * WSP_VERT: vertical split.
- * WSP_TOP:  open window at the top-left of the screen (help window).
- * WSP_BOT:  open window at the bottom-right of the screen (quickfix window).
- * WSP_HELP: creating the help window, keep layout snapshot
- *
- * return FAIL for failure, OK otherwise
- */
+// split the current window, implements CTRL-W s and :split
+//
+// "size" is the height or width for the new window, 0 to use half of current
+// height or width.
+//
+// "flags":
+// WSP_ROOM: require enough room for new window
+// WSP_VERT: vertical split.
+// WSP_TOP:  open window at the top-left of the screen (help window).
+// WSP_BOT:  open window at the bottom-right of the screen (quickfix window).
+// WSP_HELP: creating the help window, keep layout snapshot
+//
+// return FAIL for failure, OK otherwise
 int win_split(int size, int flags)
 {
   if (check_split_disallowed() == FAIL) {
@@ -1012,35 +1058,20 @@ int win_split(int size, int flags)
   return win_split_ins(size, flags, NULL, 0);
 }
 
-/*
- * When "new_wp" is NULL: split the current window in two.
- * When "new_wp" is not NULL: insert this window at the far
- * top/left/right/bottom.
- * return FAIL for failure, OK otherwise
- */
+// When "new_wp" is NULL: split the current window in two.
+// When "new_wp" is not NULL: insert this window at the far
+// top/left/right/bottom.
+// return FAIL for failure, OK otherwise
 int win_split_ins(int size, int flags, win_T *new_wp, int dir)
 {
   win_T *wp = new_wp;
-  win_T *oldwin;
-  int new_size = size;
-  int i;
-  int need_status = 0;
-  bool do_equal = false;
-  int needed;
-  int available;
-  int oldwin_height = 0;
-  int layout;
-  frame_T *frp, *curfrp, *frp2, *prevfrp;
-  int before;
-  int minheight;
-  int wmh1;
-  bool did_set_fraction = false;
 
-  // aucmd_win should always remain floating
-  if (new_wp != NULL && new_wp == aucmd_win) {
+  // aucmd_win[] should always remain floating
+  if (new_wp != NULL && is_aucmd_win(new_wp)) {
     return FAIL;
   }
 
+  win_T *oldwin;
   if (flags & WSP_TOP) {
     oldwin = firstwin;
   } else if (flags & WSP_BOT || curwin->w_floating) {
@@ -1050,6 +1081,8 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
     oldwin = curwin;
   }
 
+  int need_status = 0;
+  int new_size = size;
   bool new_in_layout = (new_wp == NULL || new_wp->w_floating);
 
   // add a status line when p_ls == 1 and splitting the first window
@@ -1061,32 +1094,33 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
     need_status = STATUS_HEIGHT;
   }
 
-  if (flags & WSP_VERT) {
-    int wmw1;
-    int minwidth;
-
-    layout = FR_ROW;
+  bool do_equal = false;
+  int oldwin_height = 0;
+  const int layout = flags & WSP_VERT ? FR_ROW : FR_COL;
+  bool did_set_fraction = false;
 
-    /*
-     * Check if we are able to split the current window and compute its
-     * width.
-     */
+  if (flags & WSP_VERT) {
+    // Check if we are able to split the current window and compute its
+    // width.
     // Current window requires at least 1 space.
-    wmw1 = (p_wmw == 0 ? 1 : (int)p_wmw);
-    needed = wmw1 + 1;
+    int wmw1 = (p_wmw == 0 ? 1 : (int)p_wmw);
+    int needed = wmw1 + 1;
     if (flags & WSP_ROOM) {
       needed += (int)p_wiw - wmw1;
     }
+    int minwidth;
+    int available;
     if (flags & (WSP_BOT | WSP_TOP)) {
       minwidth = frame_minwidth(topframe, NOWIN);
       available = topframe->fr_width;
       needed += minwidth;
     } else if (p_ea) {
       minwidth = frame_minwidth(oldwin->w_frame, NOWIN);
-      prevfrp = oldwin->w_frame;
-      for (frp = oldwin->w_frame->fr_parent; frp != NULL;
+      frame_T *prevfrp = oldwin->w_frame;
+      for (frame_T *frp = oldwin->w_frame->fr_parent; frp != NULL;
            frp = frp->fr_parent) {
         if (frp->fr_layout == FR_ROW) {
+          frame_T *frp2;
           FOR_ALL_FRAMES(frp2, frp->fr_child) {
             if (frp2 != prevfrp) {
               minwidth += frame_minwidth(frp2, NOWIN);
@@ -1132,7 +1166,7 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
     // is wider than one of the split windows.
     if (!do_equal && p_ea && size == 0 && *p_ead != 'v'
         && oldwin->w_frame->fr_parent != NULL) {
-      frp = oldwin->w_frame->fr_parent->fr_child;
+      frame_T *frp = oldwin->w_frame->fr_parent->fr_child;
       while (frp != NULL) {
         if (frp->fr_win != oldwin && frp->fr_win != NULL
             && (frp->fr_win->w_width > new_size
@@ -1145,27 +1179,28 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
       }
     }
   } else {
-    layout = FR_COL;
-
     // Check if we are able to split the current window and compute its height.
     // Current window requires at least 1 space plus space for the window bar.
-    wmh1 = MAX((int)p_wmh, 1) + oldwin->w_winbar_height;
-    needed = wmh1 + STATUS_HEIGHT;
+    int wmh1 = MAX((int)p_wmh, 1) + oldwin->w_winbar_height;
+    int needed = wmh1 + STATUS_HEIGHT;
     if (flags & WSP_ROOM) {
       needed += (int)p_wh - wmh1 + oldwin->w_winbar_height;
     }
     if (p_ch < 1) {
       needed += 1;  // Adjust for cmdheight=0.
     }
+    int minheight;
+    int available;
     if (flags & (WSP_BOT | WSP_TOP)) {
       minheight = frame_minheight(topframe, NOWIN) + need_status;
       available = topframe->fr_height;
       needed += minheight;
     } else if (p_ea) {
       minheight = frame_minheight(oldwin->w_frame, NOWIN) + need_status;
-      prevfrp = oldwin->w_frame;
-      for (frp = oldwin->w_frame->fr_parent; frp != NULL; frp = frp->fr_parent) {
+      frame_T *prevfrp = oldwin->w_frame;
+      for (frame_T *frp = oldwin->w_frame->fr_parent; frp != NULL; frp = frp->fr_parent) {
         if (frp->fr_layout == FR_COL) {
+          frame_T *frp2;
           FOR_ALL_FRAMES(frp2, frp->fr_child) {
             if (frp2 != prevfrp) {
               minheight += frame_minheight(frp2, NOWIN);
@@ -1228,7 +1263,7 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
     if (!do_equal && p_ea && size == 0
         && *p_ead != 'h'
         && oldwin->w_frame->fr_parent != NULL) {
-      frp = oldwin->w_frame->fr_parent->fr_child;
+      frame_T *frp = oldwin->w_frame->fr_parent->fr_child;
       while (frp != NULL) {
         if (frp->fr_win != oldwin && frp->fr_win != NULL
             && (frp->fr_win->w_height > new_size
@@ -1241,9 +1276,7 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
     }
   }
 
-  /*
-   * allocate new window structure and link it in the window list
-   */
+  // allocate new window structure and link it in the window list
   if ((flags & WSP_TOP) == 0
       && ((flags & WSP_BOT)
           || (flags & WSP_BELOW)
@@ -1280,9 +1313,10 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
     CLEAR_FIELD(wp->w_border_adj);
   }
 
-  /*
-   * Reorganise the tree of frames to insert the new window.
-   */
+  int before;
+  frame_T *curfrp;
+
+  // Reorganise the tree of frames to insert the new window.
   if (flags & (WSP_TOP | WSP_BOT)) {
     if ((topframe->fr_layout == FR_COL && (flags & WSP_VERT) == 0)
         || (topframe->fr_layout == FR_ROW && (flags & WSP_VERT) != 0)) {
@@ -1299,9 +1333,9 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
   } else {
     curfrp = oldwin->w_frame;
     if (flags & WSP_BELOW) {
-      before = FALSE;
+      before = false;
     } else if (flags & WSP_ABOVE) {
-      before = TRUE;
+      before = true;
     } else if (flags & WSP_VERT) {
       before = !p_spr;
     } else {
@@ -1310,7 +1344,7 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
   }
   if (curfrp->fr_parent == NULL || curfrp->fr_parent->fr_layout != layout) {
     // Need to create a new frame in the tree to make a branch.
-    frp = xcalloc(1, sizeof(frame_T));
+    frame_T *frp = xcalloc(1, sizeof(frame_T));
     *frp = *curfrp;
     curfrp->fr_layout = (char)layout;
     frp->fr_parent = curfrp;
@@ -1328,6 +1362,7 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
     }
   }
 
+  frame_T *frp;
   if (new_wp == NULL) {
     frp = wp->w_frame;
   } else {
@@ -1474,8 +1509,8 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
 
   // Both windows need redrawing.  Update all status lines, in case they
   // show something related to the window count or position.
-  redraw_later(wp, NOT_VALID);
-  redraw_later(oldwin, NOT_VALID);
+  redraw_later(wp, UPD_NOT_VALID);
+  redraw_later(oldwin, UPD_NOT_VALID);
   status_redraw_all();
 
   if (need_status) {
@@ -1487,13 +1522,15 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
     msg_col = 0;        // put position back at start of line
   }
 
-  /*
-   * equalize the window sizes.
-   */
+  // equalize the window sizes.
   if (do_equal || dir != 0) {
     win_equal(wp, true, (flags & WSP_VERT) ? (dir == 'v' ? 'b' : 'h') : (dir == 'h' ? 'b' : 'v'));
+  } else if (*p_spk != 'c' && !is_aucmd_win(wp)) {
+    win_fix_scroll(false);
   }
 
+  int i;
+
   // Don't change the window height/width to 'winheight' / 'winwidth' if a
   // size was given.
   if (flags & WSP_VERT) {
@@ -1525,17 +1562,13 @@ int win_split_ins(int size, int flags, win_T *new_wp, int dir)
   return OK;
 }
 
-/*
- * Initialize window "newp" from window "oldp".
- * Used when splitting a window and when creating a new tab page.
- * The windows will both edit the same buffer.
- * WSP_NEWLOC may be specified in flags to prevent the location list from
- * being copied.
- */
+// Initialize window "newp" from window "oldp".
+// Used when splitting a window and when creating a new tab page.
+// The windows will both edit the same buffer.
+// WSP_NEWLOC may be specified in flags to prevent the location list from
+// being copied.
 static void win_init(win_T *newp, win_T *oldp, int flags)
 {
-  int i;
-
   newp->w_buffer = oldp->w_buffer;
   newp->w_s = &(oldp->w_buffer->b_s);
   oldp->w_buffer->b_nwindows++;
@@ -1565,15 +1598,21 @@ static void win_init(win_T *newp, win_T *oldp, int flags)
   newp->w_prevdir = (oldp->w_prevdir == NULL)
                     ? NULL : xstrdup(oldp->w_prevdir);
 
+  if (*p_spk != 'c') {
+    newp->w_botline = oldp->w_botline;
+    newp->w_prev_height = oldp->w_height;
+    newp->w_prev_winrow = oldp->w_winrow;
+  }
+
   // copy tagstack and folds
-  for (i = 0; i < oldp->w_tagstacklen; i++) {
+  for (int i = 0; i < oldp->w_tagstacklen; i++) {
     taggy_T *tag = &newp->w_tagstack[i];
     *tag = oldp->w_tagstack[i];
     if (tag->tagname != NULL) {
-      tag->tagname = vim_strsave(tag->tagname);
+      tag->tagname = xstrdup(tag->tagname);
     }
     if (tag->user_data != NULL) {
-      tag->user_data = vim_strsave(tag->user_data);
+      tag->user_data = xstrdup(tag->user_data);
     }
   }
   newp->w_tagstackidx = oldp->w_tagstackidx;
@@ -1589,15 +1628,13 @@ static void win_init(win_T *newp, win_T *oldp, int flags)
   newp->w_winbar_height = oldp->w_winbar_height;
 }
 
-/*
- * Initialize window "newp" from window "old".
- * Only the essential things are copied.
- */
+// Initialize window "newp" from window "old".
+// Only the essential things are copied.
 static void win_init_some(win_T *newp, win_T *oldp)
 {
   // Use the same argument list.
   newp->w_alist = oldp->w_alist;
-  ++newp->w_alist->al_refcount;
+  newp->w_alist->al_refcount++;
   newp->w_arg_idx = oldp->w_arg_idx;
 
   // copy options from existing window
@@ -1627,11 +1664,20 @@ bool win_valid_floating(const win_T *win)
 /// @param  win  window to check
 bool win_valid(const win_T *win) FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
 {
+  return tabpage_win_valid(curtab, win);
+}
+
+/// Check if "win" is a pointer to an existing window in tabpage "tp".
+///
+/// @param  win  window to check
+static bool tabpage_win_valid(const tabpage_T *tp, const win_T *win)
+  FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
+{
   if (win == NULL) {
     return false;
   }
 
-  FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
+  FOR_ALL_WINDOWS_IN_TAB(wp, tp) {
     if (wp == win) {
       return true;
     }
@@ -1669,9 +1715,7 @@ bool win_valid_any_tab(win_T *win) FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
   return false;
 }
 
-/*
- * Return the number of windows.
- */
+// Return the number of windows.
 int win_count(void)
 {
   int count = 0;
@@ -1692,7 +1736,6 @@ int win_count(void)
 int make_windows(int count, bool vertical)
 {
   int maxcount;
-  int todo;
 
   if (vertical) {
     // Each window needs at least 'winminwidth' lines and a separator column.
@@ -1722,8 +1765,10 @@ int make_windows(int count, bool vertical)
   // when putting the buffers in the windows.
   block_autocmds();
 
+  int todo;
+
   // todo is number of windows left to create
-  for (todo = count - 1; todo > 0; --todo) {
+  for (todo = count - 1; todo > 0; todo--) {
     if (vertical) {
       if (win_split(curwin->w_width - (curwin->w_width - todo)
                     / (todo + 1) - 1, WSP_VERT | WSP_ABOVE) == FAIL) {
@@ -1744,17 +1789,9 @@ int make_windows(int count, bool vertical)
   return count - todo;
 }
 
-/*
- * Exchange current and next window
- */
+// Exchange current and next window
 static void win_exchange(long Prenum)
 {
-  frame_T *frp;
-  frame_T *frp2;
-  win_T *wp;
-  win_T *wp2;
-  int temp;
-
   if (curwin->w_floating) {
     emsg(e_floatexchange);
     return;
@@ -1766,9 +1803,9 @@ static void win_exchange(long Prenum)
     return;
   }
 
-  /*
-   * find window to exchange with
-   */
+  frame_T *frp;
+
+  // find window to exchange with
   if (Prenum) {
     frp = curwin->w_frame->fr_parent->fr_child;
     while (frp != NULL && --Prenum > 0) {
@@ -1785,18 +1822,16 @@ static void win_exchange(long Prenum)
   if (frp == NULL || frp->fr_win == NULL || frp->fr_win == curwin) {
     return;
   }
-  wp = frp->fr_win;
-
-  /*
-   * 1. remove curwin from the list. Remember after which window it was in wp2
-   * 2. insert curwin before wp in the list
-   * if wp != wp2
-   *    3. remove wp from the list
-   *    4. insert wp after wp2
-   * 5. exchange the status line height, winbar height, hsep height and vsep width.
-   */
-  wp2 = curwin->w_prev;
-  frp2 = curwin->w_frame->fr_prev;
+  win_T *wp = frp->fr_win;
+
+  // 1. remove curwin from the list. Remember after which window it was in wp2
+  // 2. insert curwin before wp in the list
+  // if wp != wp2
+  //    3. remove wp from the list
+  //    4. insert wp after wp2
+  // 5. exchange the status line height, winbar height, hsep height and vsep width.
+  win_T *wp2 = curwin->w_prev;
+  frame_T *frp2 = curwin->w_frame->fr_prev;
   if (wp->w_prev != curwin) {
     win_remove(curwin, NULL);
     frame_remove(curwin->w_frame);
@@ -1813,7 +1848,7 @@ static void win_exchange(long Prenum)
       frame_append(frp2, wp->w_frame);
     }
   }
-  temp = curwin->w_status_height;
+  int temp = curwin->w_status_height;
   curwin->w_status_height = wp->w_status_height;
   wp->w_status_height = temp;
   temp = curwin->w_vsep_width;
@@ -1837,19 +1872,14 @@ static void win_exchange(long Prenum)
   }
 
   win_enter(wp, true);
-  redraw_later(curwin, NOT_VALID);
-  redraw_later(wp, NOT_VALID);
+  redraw_later(curwin, UPD_NOT_VALID);
+  redraw_later(wp, UPD_NOT_VALID);
 }
 
 // rotate windows: if upwards true the second window becomes the first one
 //                 if upwards false the first window becomes the second one
 static void win_rotate(bool upwards, int count)
 {
-  win_T *wp1;
-  win_T *wp2;
-  frame_T *frp;
-  int n;
-
   if (curwin->w_floating) {
     emsg(e_floatexchange);
     return;
@@ -1862,6 +1892,7 @@ static void win_rotate(bool upwards, int count)
   }
 
   // Check if all frames in this row/col have one window.
+  frame_T *frp;
   FOR_ALL_FRAMES(frp, curwin->w_frame->fr_parent->fr_child) {
     if (frp->fr_win == NULL) {
       emsg(_("E443: Cannot rotate when another window is split"));
@@ -1869,6 +1900,9 @@ static void win_rotate(bool upwards, int count)
     }
   }
 
+  win_T *wp1;
+  win_T *wp2;
+
   while (count--) {
     if (upwards) {              // first window becomes last window
       // remove first window/frame from the list
@@ -1901,7 +1935,7 @@ static void win_rotate(bool upwards, int count)
     }
 
     // exchange status height, winbar height, hsep height and vsep width of old and new last window
-    n = wp2->w_status_height;
+    int n = wp2->w_status_height;
     wp2->w_status_height = wp1->w_status_height;
     wp1->w_status_height = n;
     n = wp2->w_hsep_height;
@@ -1922,12 +1956,10 @@ static void win_rotate(bool upwards, int count)
   wp1->w_pos_changed = true;
   wp2->w_pos_changed = true;
 
-  redraw_all_later(NOT_VALID);
+  redraw_all_later(UPD_NOT_VALID);
 }
 
-/*
- * Move the current window to the very top/bottom/left/right of the screen.
- */
+// Move the current window to the very top/bottom/left/right of the screen.
 static void win_totop(int size, int flags)
 {
   int dir = 0;
@@ -1937,7 +1969,7 @@ static void win_totop(int size, int flags)
     beep_flush();
     return;
   }
-  if (curwin == aucmd_win) {
+  if (is_aucmd_win(curwin)) {
     return;
   }
   if (check_split_disallowed() == FAIL) {
@@ -1971,14 +2003,10 @@ static void win_totop(int size, int flags)
   }
 }
 
-/*
- * Move window "win1" to below/right of "win2" and make "win1" the current
- * window.  Only works within the same frame!
- */
+// Move window "win1" to below/right of "win2" and make "win1" the current
+// window.  Only works within the same frame!
 void win_move_after(win_T *win1, win_T *win2)
 {
-  int height;
-
   // check if the arguments are reasonable
   if (win1 == win2) {
     return;
@@ -1994,7 +2022,7 @@ void win_move_after(win_T *win1, win_T *win2)
     // may need to move the status line, window bar, horizontal or vertical separator of the last
     // window
     if (win1 == lastwin) {
-      height = win1->w_prev->w_status_height;
+      int height = win1->w_prev->w_status_height;
       win1->w_prev->w_status_height = win1->w_status_height;
       win1->w_status_height = height;
 
@@ -2011,7 +2039,7 @@ void win_move_after(win_T *win1, win_T *win2)
         win1->w_frame->fr_width += 1;
       }
     } else if (win2 == lastwin) {
-      height = win1->w_status_height;
+      int height = win1->w_status_height;
       win1->w_status_height = win2->w_status_height;
       win2-&