Merge #40621 fix(ui2)!: legacy 'ruler' inconsistencies

src/nvim/insexpand.c

@@ -5241,7 +5241,13 @@ void ins_compl_insert(bool move_cursor, bool insert_prefix)
 static void ins_compl_show_filename(void)
 {
   char *const lead = _("match in file");
-  int space = sc_col - vim_strsize(lead) - 2;
+
+  // In the case of ext_messages, `sc_col` is obsolete. Fortunately, long messages are no longer
+  // disruptive, so truncation could be skipped. But in this particular case, with default
+  // configuration `showmode cmdheight=1`, a multi-line message is shown partially, and a message
+  // that fits into one line is not shown at all. It's better to be consistent: it should not depend
+  // on the exact length of the message whether it is displayed at all.
+  int space = (ui_has(kUIMessages) ? Columns : sc_col) - vim_strsize(lead) - 2;
   if (space <= 0) {
     return;
   }

src/nvim/message.c

@@ -511,7 +511,12 @@ char *msg_strtrunc(const char *s, int force)
       room = (Rows - msg_row) * Columns - 1;
     } else {
       // Use up to 'showcmd' column.
-      room = (Rows - msg_row - 1) * Columns + sc_col - 1;
+      // In the case of ui2, we no longer need to avoid the "Press ENTER" prompt, but the message is
+      // still kept under 1 line to avoid glitches. For example, when a long search term is
+      // displayed that expands the cmdline, it will be immediately collapsed again when the search
+      // count is displayed, which leads to flickering on each hit.
+      int last_row = ui_has(kUIMessages) ? Columns : sc_col - 1;
+      room = (Rows - msg_row - 1) * Columns + last_row;
     }
     if (len > room && room > 0) {
       // may have up to 18 bytes per cell (6 per char, up to two

src/nvim/options.lua

@@ -7072,6 +7072,13 @@ local options = {
         Example: >vim
         	set rulerformat=%15(%c%V\ %p%%%)
         <
+        This looks like an item group, but there are some differences in this
+        particular case.  Most notably, the width is fixed and not a minimum,
+        and the ruler is left-aligned, whereas the alignment of item groups is
+        configurable and right-aligned by default.
+
+        When |ui2| is enabled, the ruler no longer has a fixed width and the
+        item group syntax has no special meaning for 'rulerformat'.
       ]=],
       full_name = 'rulerformat',
       modelineexpr = true,

src/nvim/optionstr.c

@@ -52,6 +52,7 @@
 #include "nvim/tag.h"
 #include "nvim/terminal.h"
 #include "nvim/types_defs.h"
+#include "nvim/ui.h"
 #include "nvim/vim_defs.h"
 #include "nvim/window.h"
 #include "nvim/winfloat.h"
@@ -1917,7 +1918,7 @@ static const char *did_set_statustabline_rulerformat(optset_T *args, bool rulerf
     win_config_float(win, win->w_config);
   }
 
-  if (rulerformat && *s == '%') {
+  if (rulerformat && !ui_has(kUIMessages) && *s == '%') {
     // set ru_wid if 'ruf' starts with "%99("
     if (*++s == '-') {        // ignore a '-'
       s++;
@@ -1932,8 +1933,8 @@ static const char *did_set_statustabline_rulerformat(optset_T *args, bool rulerf
         errmsg = check_stl_option(p_ruf);
       }
     }
-  } else if (rulerformat || s[0] != '%' || s[1] != '!') {
-    // check 'statusline', 'winbar', 'tabline' or 'statuscolumn'
+  } else if (s[0] != '%' || s[1] != '!') {
+    // check 'statusline', 'rulerformat', 'winbar', 'tabline' or 'statuscolumn'
     // only if it doesn't start with "%!"
     errmsg = check_stl_option(s);
   }

src/nvim/statusline.c

@@ -308,7 +308,15 @@ static void win_redr_stl_expr(win_T *wp, bool draw_winbar, bool draw_ruler, bool
     wp->w_status_click_defs = stl_alloc_click_defs(wp->w_status_click_defs, maxwidth,
                                                    &wp->w_status_click_defs_size);
 
-    if (draw_ruler) {
+    if (draw_ruler && ui_event) {
+      stl = p_ruf;
+      opt_idx = kOptRulerformat;
+      maxwidth = Columns / 2;
+      if (!in_status_line) {
+        fillchar = schar_from_ascii(' ');
+        group = HLF_MSG;
+      }
+    } else if (draw_ruler) {
       stl = p_ruf;
       opt_idx = kOptRulerformat;
       // advance past any leading group spec - implicit in ru_col
@@ -549,8 +557,8 @@ void redraw_ruler(void)
   char rel_pos[RULER_BUF_LEN];
   int rel_poslen = get_rel_pos(wp, rel_pos, RULER_BUF_LEN);
   int n1 = bufferlen + vim_strsize(rel_pos);
-  if (wp->w_status_height == 0 && !is_stl_global) {  // can't use last char of screen
-    n1++;
+  if (wp->w_status_height == 0 && !is_stl_global && !ui_has(kUIMessages)) {
+    n1++;  // can't use last char of screen
   }
 
   int this_ru_col = ru_col - (Columns - width);
@@ -1464,9 +1472,8 @@ int build_stl_str_hl(win_T *wp, char *out, size_t outlen, char *fmt, OptIndex op
       }
     }
 
-    // Bound the minimum width at 50.
     // Make the number negative to denote left alignment of the item
-    minwid = (minwid > 50 ? 50 : minwid) * (left_align ? -1 : 1);
+    minwid *= left_align ? -1 : 1;
 
     // Denotes the start of a new group
     if (*fmt_p == '(') {

src/nvim/vvars.lua

@@ -145,7 +145,7 @@ M.vars = {
     desc = [=[
       Number of screen cells that can be used for an `:echo` message
       in the last screen line before causing the |hit-enter| prompt
-      (or "overflow" with |ui2|).
+      (no longer applicable when |ui2| is enabled).
 
       Depends on 'showcmd', 'ruler' and 'columns'.  You need to
       check 'cmdheight' for whether there are full-width lines