fix(extmarks): don't position overlay virt_text halfway a char (#24027)

src/nvim/drawline.c

@@ -871,10 +871,6 @@ static void apply_cursorline_highlight(win_T *wp, winlinevars_T *wlv)
 
 static void handle_inline_virtual_text(win_T *wp, winlinevars_T *wlv, ptrdiff_t v, bool *do_save)
 {
-  if (wlv->n_extra == 0 || !wlv->extra_for_extmark) {
-    wlv->reset_extra_attr = false;
-  }
-
   while (wlv->n_extra == 0) {
     if (wlv->virt_inline_i >= kv_size(wlv->virt_inline)) {
       // need to find inline virtual text
@@ -1763,50 +1759,10 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool number_onl
       break;
     }
 
-    if (wlv.draw_state == WL_LINE
+    const bool draw_folded = wlv.draw_state == WL_LINE && has_fold
-        && has_fold
+                             && wlv.row == startrow + wlv.filler_lines;
-        && wlv.col == win_col_offset
+    if (draw_folded && wlv.n_extra == 0) {
-        && wlv.n_extra == 0
-        && wlv.row == startrow + wlv.filler_lines) {
       wlv.char_attr = folded_attr = win_hl_attr(wp, HLF_FL);
-
-      linenr_T lnume = lnum + foldinfo.fi_lines - 1;
-      memset(buf_fold, ' ', FOLD_TEXT_LEN);
-      wlv.p_extra = get_foldtext(wp, lnum, lnume, foldinfo, buf_fold);
-      wlv.n_extra = (int)strlen(wlv.p_extra);
-
-      if (wlv.p_extra != buf_fold) {
-        xfree(wlv.p_extra_free);
-        wlv.p_extra_free = wlv.p_extra;
-      }
-      wlv.c_extra = NUL;
-      wlv.c_final = NUL;
-      wlv.p_extra[wlv.n_extra] = NUL;
-
-      // Get the line again as evaluating 'foldtext' may free it.
-      line = ml_get_buf(wp->w_buffer, lnum, false);
-      ptr = line + v;
-    }
-
-    if (wlv.draw_state == WL_LINE
-        && has_fold
-        && wlv.col < grid->cols
-        && wlv.n_extra == 0
-        && wlv.row == startrow + wlv.filler_lines) {
-      // fill rest of line with 'fold'
-      wlv.c_extra = wp->w_p_fcs_chars.fold;
-      wlv.c_final = NUL;
-
-      wlv.n_extra = wp->w_p_rl ? (wlv.col + 1) : (grid->cols - wlv.col);
-    }
-
-    if (wlv.draw_state == WL_LINE
-        && has_fold
-        && wlv.col >= grid->cols
-        && wlv.n_extra != 0
-        && wlv.row == startrow + wlv.filler_lines) {
-      // Truncate the folding.
-      wlv.n_extra = 0;
     }
 
     int extmark_attr = 0;
@@ -1829,7 +1785,11 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool number_onl
         area_active = false;
       }
 
-      if (has_decor && v >= 0) {
+      if (wlv.n_extra == 0 || !wlv.extra_for_extmark) {
+        wlv.reset_extra_attr = false;
+      }
+
+      if (has_decor && v >= 0 && wlv.n_extra == 0) {
         bool selected = (area_active || (area_highlighting && noinvcur
                                          && wlv.vcol == wp->w_virtcol));
         extmark_attr = decor_redraw_col(wp, (colnr_T)v, wlv.off, selected, &decor_state);
@@ -1919,6 +1879,37 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool number_onl
       }
     }
 
+    if (draw_folded && wlv.n_extra == 0 && wlv.col == win_col_offset) {
+      linenr_T lnume = lnum + foldinfo.fi_lines - 1;
+      memset(buf_fold, ' ', FOLD_TEXT_LEN);
+      wlv.p_extra = get_foldtext(wp, lnum, lnume, foldinfo, buf_fold);
+      wlv.n_extra = (int)strlen(wlv.p_extra);
+
+      if (wlv.p_extra != buf_fold) {
+        xfree(wlv.p_extra_free);
+        wlv.p_extra_free = wlv.p_extra;
+      }
+      wlv.c_extra = NUL;
+      wlv.c_final = NUL;
+      wlv.p_extra[wlv.n_extra] = NUL;
+
+      // Get the line again as evaluating 'foldtext' may free it.
+      line = ml_get_buf(wp->w_buffer, lnum, false);
+      ptr = line + v;
+    }
+
+    if (draw_folded && wlv.n_extra == 0 && wlv.col < grid->cols) {
+      // Fill rest of line with 'fold'.
+      wlv.c_extra = wp->w_p_fcs_chars.fold;
+      wlv.c_final = NUL;
+      wlv.n_extra = wp->w_p_rl ? (wlv.col + 1) : (grid->cols - wlv.col);
+    }
+
+    if (draw_folded && wlv.n_extra != 0 && wlv.col >= grid->cols) {
+      // Truncate the folding.
+      wlv.n_extra = 0;
+    }
+
     // Get the next character to put on the screen.
     //
     // The "p_extra" points to the extra stuff that is inserted to

test/functional/ui/decorations_spec.lua

@@ -667,6 +667,8 @@ describe('extmark decorations', function()
       [31] = {underline = true, foreground = Screen.colors.DarkCyan};
       [32] = {underline = true};
       [33] = {foreground = Screen.colors.DarkBlue, background = Screen.colors.LightGray};
+      [34] = {background = Screen.colors.Yellow};
+      [35] = {background = Screen.colors.Yellow, bold = true, foreground = Screen.colors.Blue};
     }
 
     ns = meths.create_namespace 'test'
@@ -890,6 +892,25 @@ describe('extmark decorations', function()
     ]]}
   end)
 
+  it('overlay virtual text works on and after a TAB #24022', function()
+    screen:try_resize(40, 3)
+    meths.buf_set_lines(0, 0, -1, true, {'\t\tline 1'})
+    meths.buf_set_extmark(0, ns, 0, 0, { virt_text = {{'AA', 'Search'}}, virt_text_pos = 'overlay', hl_mode = 'combine' })
+    meths.buf_set_extmark(0, ns, 0, 1, { virt_text = {{'BB', 'Search'}}, virt_text_pos = 'overlay', hl_mode = 'combine' })
+    meths.buf_set_extmark(0, ns, 0, 2, { virt_text = {{'CC', 'Search'}}, virt_text_pos = 'overlay', hl_mode = 'combine' })
+    screen:expect{grid=[[
+      {34:AA}     ^ {34:BB}      {34:CC}ne 1                  |
+      {1:~                                       }|
+                                              |
+    ]]}
+    command('setlocal list listchars=tab:<->')
+    screen:expect{grid=[[
+      {35:^AA}{1:----->}{35:BB}{1:----->}{34:CC}ne 1                  |
+      {1:~                                       }|
+                                              |
+    ]]}
+  end)
+
   it('can have virtual text of overlay position and styling', function()
     insert(example_text)
     feed 'gg'