vim-patch:9.1.1250: cannot set the maximum popup menu width

Problem:  cannot set the maximum popup menu width
          (Lucas Mior)
Solution: add the new global option value 'pummaxwidth'
          (glepnir)

fixes: vim/vim#10901
closes: vim/vim#16943

https://github.com/vim/vim/commit/88d75934c3d5bc4c406343f106e1a61638abd3a7

Co-authored-by: glepnir <glephunter@gmail.com>

3 files changed, 124 insertions, 1 deletions

diff --git a/src/nvim/option_vars.h b/src/nvim/option_vars.h
index 0b5d0a45b4..e624ab80ef 100644
--- a/src/nvim/option_vars.h
+++ b/src/nvim/option_vars.h
@@ -306,6 +306,7 @@ EXTERN char *p_csl;             ///< 'completeslash'
 EXTERN OptInt p_pb;             ///< 'pumblend'
 EXTERN OptInt p_ph;             ///< 'pumheight'
 EXTERN OptInt p_pw;             ///< 'pumwidth'
+EXTERN OptInt p_pmw;            ///< 'pummaxwidth'
 EXTERN char *p_com;             ///< 'comments'
 EXTERN char *p_cpo;             ///< 'cpoptions'
 EXTERN char *p_debug;           ///< 'debug'
diff --git a/src/nvim/options.lua b/src/nvim/options.lua
index 2f77d0ebb7..f261abf30e 100644
--- a/src/nvim/options.lua
+++ b/src/nvim/options.lua
@@ -6426,6 +6426,21 @@ local options = {
       varname = 'p_ph',
     },
     {
+      abbreviation = 'pmw',
+      defaults = 0,
+      desc = [=[
+        Maximum width for the popup menu (|ins-completion-menu|).  When zero,
+        there is no maximum width limit, otherwise the popup menu will never be
+        wider than this value.  Truncated text will be indicated by "..." at the
+        end.  Takes precedence over 'pumwidth'.
+      ]=],
+      full_name = 'pummaxwidth',
+      scope = { 'global' },
+      short_desc = N_('maximum width of the popup menu'),
+      type = 'number',
+      varname = 'p_pmw',
+    },
+    {
       abbreviation = 'pw',
       defaults = 15,
       desc = [=[
diff --git a/src/nvim/popupmenu.c b/src/nvim/popupmenu.c
index d26651fb84..75f1c93ed7 100644
--- a/src/nvim/popupmenu.c
+++ b/src/nvim/popupmenu.c
@@ -199,6 +199,9 @@ void pum_display(pumitem_T *array, int size, int selected, bool array_changed, i
     }
 
     int def_width = (int)p_pw;
+    if (p_pmw > 0 && def_width > p_pmw) {
+      def_width = (int)p_pmw;
+    }
 
     win_T *pvwin = NULL;
     FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
@@ -307,6 +310,9 @@ void pum_display(pumitem_T *array, int size, int selected, bool array_changed, i
 
     pum_compute_size();
     int max_width = pum_base_width;
+    if (p_pmw > 0 && max_width > p_pmw) {
+      max_width = (int)p_pmw;
+    }
 
     // if there are more items than room we need a scrollbar
     if (pum_height < size) {
@@ -339,6 +345,9 @@ void pum_display(pumitem_T *array, int size, int selected, bool array_changed, i
       if (pum_width > content_width && pum_width > p_pw) {
         // Reduce width to fit item
         pum_width = MAX(content_width, (int)p_pw);
+        if (p_pmw > 0 && pum_width > p_pmw) {
+          pum_width = (int)p_pmw;
+        }
       } else if (((cursor_col - min_col > p_pw
                    || cursor_col - min_col > max_width) && !pum_rl)
                  || (pum_rl && (cursor_col < max_col - p_pw
@@ -365,6 +374,9 @@ void pum_display(pumitem_T *array, int size, int selected, bool array_changed, i
 
         if (pum_width < p_pw) {
           pum_width = (int)p_pw;
+          if (p_pmw > 0 && pum_width > p_pmw) {
+            pum_width = (int)p_pmw;
+          }
           if (pum_rl) {
             if (pum_width > pum_col - min_col) {
               pum_width = pum_col - min_col;
@@ -376,6 +388,9 @@ void pum_display(pumitem_T *array, int size, int selected, bool array_changed, i
           }
         } else if (pum_width > content_width && pum_width > p_pw) {
           pum_width = MAX(content_width, (int)p_pw);
+          if (p_pmw > 0 && pum_width > p_pmw) {
+            pum_width = (int)p_pmw;
+          }
         }
       }
     } else if (max_col - min_col < def_width) {
@@ -386,11 +401,17 @@ void pum_display(pumitem_T *array, int size, int selected, bool array_changed, i
         pum_col = min_col;
       }
       pum_width = max_col - min_col - 1;
+      if (p_pmw > 0 && pum_width > p_pmw) {
+        pum_width = (int)p_pmw;
+      }
     } else {
       if (max_width > p_pw) {
         // truncate
         max_width = (int)p_pw;
       }
+      if (p_pmw > 0 && max_width > p_pmw) {
+        max_width = (int)p_pmw;
+      }
       if (pum_rl) {
         pum_col = min_col + max_width - 1;
       } else {
@@ -611,6 +632,8 @@ void pum_redraw(void)
     thumb_pos = (pum_first * (pum_height - thumb_height) + scroll_range / 2) / scroll_range;
   }
 
+  const int ellipsis_width = 3;
+
   for (int i = 0; i < pum_height; i++) {
     int idx = i + pum_first;
     const hlf_T *const hlfs = (idx == pum_selected) ? hlfsSel : hlfsNorm;
@@ -685,6 +708,9 @@ void pum_redraw(void)
             char *rt = reverse_text(st);
             char *rt_start = rt;
             int cells = vim_strsize(rt);
+            bool need_ellipsis = p_pmw > ellipsis_width
+                                 && pum_width == p_pmw
+                                 && grid_col - cells < col_off - pum_width;
 
             if (grid_col - cells < col_off - pum_width) {
               do {
@@ -692,7 +718,41 @@ void pum_redraw(void)
                 MB_PTR_ADV(rt);
               } while (grid_col - cells < col_off - pum_width);
 
-              if (grid_col - cells > col_off - pum_width) {
+              if (need_ellipsis) {
+                char *orig_rt = rt;
+                int used_cells = 0;
+                char *last_char = NULL;
+                while (*orig_rt != NUL) {
+                  int char_cells = utf_ptr2cells(orig_rt);
+                  if (used_cells + char_cells > ellipsis_width) {
+                    break;
+                  }
+                  used_cells += char_cells;
+                  MB_PTR_ADV(orig_rt);
+                  last_char = orig_rt;
+                }
+
+                if (last_char != NULL) {
+                  int over_cell = 0;
+                  if (used_cells < ellipsis_width) {
+                    over_cell = ellipsis_width - used_cells;
+                    MB_PTR_ADV(orig_rt);
+                    last_char = orig_rt;
+                  }
+                  size_t kept_len = strlen(last_char);
+                  char *new_str = xmalloc((size_t)ellipsis_width + (size_t)over_cell
+                                          + kept_len + 1);
+                  memset(new_str, '.', (size_t)ellipsis_width);
+                  if (over_cell > 0) {
+                    memset(new_str + ellipsis_width, ' ', (size_t)over_cell);
+                  }
+                  memcpy(new_str + ellipsis_width + over_cell, last_char, kept_len);
+                  new_str[(size_t)ellipsis_width + kept_len + (size_t)over_cell] = NUL;
+                  char *old_rt = rt_start;
+                  rt = rt_start = new_str;
+                  xfree(old_rt);
+                }
+              } else if (grid_col - cells > col_off - pum_width) {
                 // Most left character requires 2-cells but only 1 cell is available on
                 // screen.  Put a '<' on the left of the pum item.
                 *(--rt) = '<';
@@ -710,6 +770,53 @@ void pum_redraw(void)
             xfree(st);
             grid_col -= width;
           } else {
+            size_t size = strlen(st);
+            int cells = (int)mb_string2cells_len(st, size);
+            bool need_ellipsis = p_pmw > ellipsis_width
+                                 && pum_width == p_pmw
+                                 && grid_col + cells > col_off + pum_width;
+
+            // Add '...' indicator if truncated due to p_pmw
+            if (need_ellipsis) {
+              while (size > 0 && grid_col + cells > col_off + pum_width) {
+                size--;
+                size -= (size_t)utf_head_off(st, st + size);
+                cells -= utf_ptr2cells(st + size);
+              }
+              char *st_end = st + size;
+              int used_cells = 0;
+              char *last_char = NULL;
+              while (st_end > st) {
+                int char_cells = utf_ptr2cells(st_end);
+                if (used_cells + char_cells > ellipsis_width) {
+                  break;
+                }
+                used_cells += char_cells;
+                MB_PTR_BACK(st, st_end);
+                last_char = st_end;
+              }
+
+              if (last_char != NULL) {
+                int over_cell = 0;
+                if (used_cells < ellipsis_width) {
+                  MB_PTR_BACK(st, st_end);
+                  last_char = st_end;
+                  over_cell = ellipsis_width - used_cells;
+                }
+                size_t kept_len = (size_t)(last_char - st);
+                char *new_str = xmalloc((size_t)ellipsis_width + (size_t)over_cell
+                                        + kept_len + 1);
+                memcpy(new_str, st, kept_len);
+                if (over_cell > 0) {
+                  memset(new_str + kept_len, ' ', (size_t)over_cell);
+                }
+                memset(new_str + kept_len + over_cell, '.', (size_t)ellipsis_width);
+                new_str[kept_len + (size_t)ellipsis_width + (size_t)over_cell] = NUL;
+                xfree(st);
+                st = new_str;
+              }
+            }
+
             if (attrs == NULL) {
               grid_line_puts(grid_col, st, -1, attr);
             } else {