fix(plines): handle inline virtual text after last char (#24241)

Also remove dead code in win_lbr_chartabsize().

src/nvim/plines.c

@@ -298,9 +298,8 @@ void win_linetabsize_cts(chartabsize_T *cts, colnr_T len)
        MB_PTR_ADV(cts->cts_ptr)) {
     cts->cts_vcol += win_lbr_chartabsize(cts, NULL);
   }
-  // check for a virtual text on an empty line
-  if (cts->cts_has_virt_text && *cts->cts_ptr == NUL
-      && cts->cts_ptr == cts->cts_line) {
+  // check for a virtual text after the end of the line
+  if (len == MAXCOL && cts->cts_has_virt_text && *cts->cts_ptr == NUL) {
     (void)win_lbr_chartabsize(cts, NULL);
     cts->cts_vcol += cts->cts_cur_text_width_left + cts->cts_cur_text_width_right;
   }
@@ -406,15 +405,15 @@ int win_lbr_chartabsize(chartabsize_T *cts, int *headp)
 
   // First get normal size, without 'linebreak' or virtual text
   int size = win_chartabsize(wp, s, vcol);
+
   if (cts->cts_has_virt_text) {
     int tab_size = size;
-    int charlen = *s == NUL ? 1 : utf_ptr2len(s);
     int col = (int)(s - line);
     while (true) {
       mtkey_t mark = marktree_itr_current(cts->cts_iter);
       if (mark.pos.row != cts->cts_row || mark.pos.col > col) {
         break;
-      } else if (mark.pos.col >= col && mark.pos.col < col + charlen) {
+      } else if (mark.pos.col == col) {
         if (!mt_end(mark)) {
           Decoration decor = get_decor(mark);
           if (decor.virt_text_pos == kVTInline) {

src/nvim/plines.h

@@ -6,19 +6,19 @@
 #include "nvim/buffer_defs.h"
 #include "nvim/vim.h"
 
-// Argument for lbr_chartabsize().
+/// Argument for lbr_chartabsize().
 typedef struct {
   win_T *cts_win;
-  char *cts_line;    // start of the line
-  char *cts_ptr;     // current position in line
+  char *cts_line;                ///< start of the line
+  char *cts_ptr;                 ///< current position in line
   int cts_row;
 
-  bool cts_has_virt_text;  // true if if a property inserts text
-  int cts_cur_text_width_left;     // width of virtual text left of cursor
-  int cts_cur_text_width_right;     // width of virtual text right of cursor
+  bool cts_has_virt_text;        ///< true if if there is inline virtual text
+  int cts_cur_text_width_left;   ///< width of virtual text left of cursor
+  int cts_cur_text_width_right;  ///< width of virtual text right of cursor
   MarkTreeIter cts_iter[1];
 
-  int cts_vcol;    // virtual column at current position
+  int cts_vcol;                  ///< virtual column at current position
 } chartabsize_T;
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS

test/functional/ui/decorations_spec.lua

@@ -1835,7 +1835,7 @@ describe('decorations: inline virtual text', function()
       ]]}
   end)
 
-  it('text is drawn correctly when inserting a wrapping virtual text on an empty line', function()
+  it('text is drawn correctly with a wrapping virtual text', function()
     feed('o<esc>')
     insert([[aaaaaaa
 
@@ -1899,6 +1899,40 @@ bbbbbbb]])
       {1:~                                                 }|
                                                         |
       ]]}
+
+    feed('ggic')
+    screen:expect { grid = [[
+      c{10:^XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX}|
+      {10:XX}                                                |
+      aaaaaaa                                           |
+      {10:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX}|
+      bbbbbbb                                           |
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {8:-- INSERT --}                                      |
+      ]]}
+  end)
+
+  it('regexp \\%V does not count trailing virtual text', function()
+    screen:try_resize(50, 4)
+    meths.buf_set_lines(0, 0, -1, true, {'foofoo', '', 'foofoo'})
+    meths.buf_set_extmark(0, ns, 1, 0, { virt_text = {{'barbarbar', 'Special'}}, virt_text_pos = 'inline' })
+    feed([[<C-V>G5l<Esc>/foo\n\%V<CR>]])
+    screen:expect{grid=[[
+      foo{12:^foo }                                           |
+      {10:barbarbar}                                         |
+      foofoo                                            |
+      {16:search hit BOTTOM, continuing at TOP}              |
+    ]]}
+    feed([[jIbaz<Esc>/foo\nbaz\%V<CR>]])
+    screen:expect{grid=[[
+      foo{12:^foo }                                           |
+      {12:baz}{10:barbarbar}                                      |
+      foofoo                                            |
+      {16:search hit BOTTOM, continuing at TOP}              |
+    ]]}
   end)
 
   it('cursor position is correct with virtual text attached to hard tabs', function()