fix(drawline): correct highlight priority with Visual selection (#30706)

4 files changed, 55 insertions, 44 deletions

diff --git a/src/nvim/drawline.c b/src/nvim/drawline.c
index 3b88dd2e90..79f3298eb4 100644
--- a/src/nvim/drawline.c
+++ b/src/nvim/drawline.c
@@ -927,7 +927,8 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, int col_rows, s
   bool noinvcur = false;                // don't invert the cursor
   bool lnum_in_visual_area = false;
 
-  bool attr_pri = false;                // char_attr has priority
+  int char_attr_pri = 0;                // attributes with high priority
+  int char_attr_base = 0;               // attributes with low priority
   bool area_highlighting = false;       // Visual or incsearch highlighting in this line
   int vi_attr = 0;                      // attributes for Visual and incsearch highlighting
   int area_attr = 0;                    // attributes desired by highlighting
@@ -1741,16 +1742,14 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, int col_rows, s
       }
 
       // Decide which of the highlight attributes to use.
-      attr_pri = true;
-
       if (area_attr != 0) {
-        wlv.char_attr = hl_combine_attr(wlv.line_attr, area_attr);
+        char_attr_pri = hl_combine_attr(wlv.line_attr, area_attr);
         if (!highlight_match) {
           // let search highlight show in Visual area if possible
-          wlv.char_attr = hl_combine_attr(search_attr, wlv.char_attr);
+          char_attr_pri = hl_combine_attr(search_attr, char_attr_pri);
         }
       } else if (search_attr != 0) {
-        wlv.char_attr = hl_combine_attr(wlv.line_attr, search_attr);
+        char_attr_pri = hl_combine_attr(wlv.line_attr, search_attr);
       } else if (wlv.line_attr != 0
                  && ((wlv.fromcol == -10 && wlv.tocol == MAXCOL)
                      || wlv.vcol < wlv.fromcol
@@ -1758,15 +1757,12 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, int col_rows, s
                      || wlv.vcol >= wlv.tocol)) {
         // Use wlv.line_attr when not in the Visual or 'incsearch' area
         // (area_attr may be 0 when "noinvcur" is set).
-        wlv.char_attr = wlv.line_attr;
+        char_attr_pri = wlv.line_attr;
       } else {
-        attr_pri = false;
-        wlv.char_attr = decor_attr;
-      }
-
-      if (folded_attr != 0) {
-        wlv.char_attr = hl_combine_attr(folded_attr, wlv.char_attr);
+        char_attr_pri = 0;
       }
+      char_attr_base = hl_combine_attr(folded_attr, decor_attr);
+      wlv.char_attr = hl_combine_attr(char_attr_base, char_attr_pri);
     }
 
     if (draw_folded && has_foldtext && wlv.n_extra == 0 && wlv.col == win_col_offset) {
@@ -1997,25 +1993,8 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, int col_rows, s
           can_spell = TRISTATE_TO_BOOL(decor_state.spell, can_spell);
         }
 
-        if (folded_attr) {
-          decor_attr = hl_combine_attr(folded_attr, decor_attr);
-        }
-
-        if (decor_attr) {
-          if (!attr_pri) {
-            if (wlv.cul_attr) {
-              wlv.char_attr = 0 != wlv.line_attr_lowprio
-                              ? hl_combine_attr(wlv.cul_attr, decor_attr)
-                              : hl_combine_attr(decor_attr, wlv.cul_attr);
-            } else {
-              wlv.char_attr = decor_attr;
-            }
-          } else {
-            wlv.char_attr = hl_combine_attr(decor_attr, wlv.char_attr);
-          }
-        } else if (!attr_pri) {
-          wlv.char_attr = 0;
-        }
+        char_attr_base = hl_combine_attr(folded_attr, decor_attr);
+        wlv.char_attr = hl_combine_attr(char_attr_base, char_attr_pri);
 
         // Check spelling (unless at the end of the line).
         // Only do this when there is no syntax highlighting, the
@@ -2083,11 +2062,8 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, int col_rows, s
           }
         }
         if (spell_attr != 0) {
-          if (!attr_pri) {
-            wlv.char_attr = hl_combine_attr(wlv.char_attr, spell_attr);
-          } else {
-            wlv.char_attr = hl_combine_attr(spell_attr, wlv.char_attr);
-          }
+          char_attr_base = hl_combine_attr(char_attr_base, spell_attr);
+          wlv.char_attr = hl_combine_attr(char_attr_base, char_attr_pri);
         }
 
         if (wp->w_buffer->terminal) {
diff --git a/test/functional/ui/decorations_spec.lua b/test/functional/ui/decorations_spec.lua
index 042975f898..d96f614cd9 100644
--- a/test/functional/ui/decorations_spec.lua
+++ b/test/functional/ui/decorations_spec.lua
@@ -1964,7 +1964,7 @@ describe('extmark decorations', function()
     ]]}
   end)
 
-  pending('highlight applies to a full TAB in visual block mode', function()
+  it('highlight applies to a full TAB in visual block mode', function()
     screen:try_resize(50, 8)
     command('hi! Visual guifg=NONE guibg=LightGrey')
     api.nvim_buf_set_lines(0, 0, -1, true, {'asdf', '\tasdf', '\tasdf', '\tasdf', 'asdf'})
diff --git a/test/functional/ui/fold_spec.lua b/test/functional/ui/fold_spec.lua
index 2712e5ff48..8f6e8aef7e 100644
--- a/test/functional/ui/fold_spec.lua
+++ b/test/functional/ui/fold_spec.lua
@@ -55,6 +55,8 @@ describe('folded lines', function()
         },
         [19] = { background = Screen.colors.Yellow, foreground = Screen.colors.DarkBlue },
         [20] = { background = Screen.colors.Red, bold = true, foreground = Screen.colors.Blue },
+        [21] = { background = Screen.colors.LightGrey, foreground = Screen.colors.Green },
+        [22] = { background = Screen.colors.Red, foreground = Screen.colors.Green },
       })
     end)
 
@@ -2625,6 +2627,8 @@ describe('folded lines', function()
       command('hi! CursorLine guibg=NONE guifg=Red gui=NONE')
       command('hi F0 guibg=Red guifg=Black')
       command('hi F1 guifg=White')
+      command([[syn match Keyword /\<sentence\>/]])
+      command('hi! Keyword guibg=NONE guifg=Green')
       api.nvim_set_option_value('cursorline', true, {})
       api.nvim_set_option_value('foldcolumn', '4', {})
       api.nvim_set_option_value('foldtext', '', {})
@@ -2662,7 +2666,7 @@ describe('folded lines', function()
         ## grid 2
           {7:    }This is a                 |
           {7:-   }valid English             |
-          {7:│+  }{5:sentence composed by······}|
+          {7:│+  }{21:sentence}{5: composed by······}|
           {7:│+  }{13:^in his cave.··············}|
           {1:~                             }|*2
         ## grid 3
@@ -2672,7 +2676,7 @@ describe('folded lines', function()
         screen:expect([[
           {7:    }This is a                 |
           {7:-   }valid English             |
-          {7:│+  }{5:sentence composed by······}|
+          {7:│+  }{21:sentence}{5: composed by······}|
           {7:│+  }{13:^in his cave.··············}|
           {1:~                             }|*2
                                         |
@@ -2689,7 +2693,7 @@ describe('folded lines', function()
         ## grid 2
           {7:    }This is a                 |
           {7:-   }^v{14:alid English}             |
-          {7:│+  }{15:sentence composed by······}|
+          {7:│+  }{22:sentence}{15: composed by······}|
           {7:│+  }{15:in his cave.··············}|
           {1:~                             }|*2
         ## grid 3
@@ -2699,7 +2703,7 @@ describe('folded lines', function()
         screen:expect([[
           {7:    }This is a                 |
           {7:-   }^v{14:alid English}             |
-          {7:│+  }{15:sentence composed by······}|
+          {7:│+  }{22:sentence}{15: composed by······}|
           {7:│+  }{15:in his cave.··············}|
           {1:~                             }|*2
           {11:-- VISUAL LINE --}             |
@@ -2715,7 +2719,7 @@ describe('folded lines', function()
         ## grid 2
                            a si sihT{7:    }|
                        {14:hsilgnE dila}^v{7:   -}|
-          {15:······yb desopmoc ecnetnes}{7:  +│}|
+          {15:······yb desopmoc }{22:ecnetnes}{7:  +│}|
           {15:··············.evac sih ni}{7:  +│}|
           {1:                             ~}|*2
         ## grid 3
@@ -2725,7 +2729,7 @@ describe('folded lines', function()
         screen:expect([[
                            a si sihT{7:    }|
                        {14:hsilgnE dila}^v{7:   -}|
-          {15:······yb desopmoc ecnetnes}{7:  +│}|
+          {15:······yb desopmoc }{22:ecnetnes}{7:  +│}|
           {15:··············.evac sih ni}{7:  +│}|
           {1:                             ~}|*2
           {11:-- VISUAL LINE --}             |
diff --git a/test/functional/ui/spell_spec.lua b/test/functional/ui/spell_spec.lua
index da112148cd..f0fa47ebfb 100644
--- a/test/functional/ui/spell_spec.lua
+++ b/test/functional/ui/spell_spec.lua
@@ -377,4 +377,35 @@ describe("'spell'", function()
                                                  |
     ]])
   end)
+
+  it('overrides syntax when Visual selection is active', function()
+    screen:try_resize(43, 3)
+    screen:set_default_attr_ids({
+      [0] = { bold = true, foreground = Screen.colors.Blue },
+      [1] = { foreground = Screen.colors.Blue },
+      [2] = { foreground = Screen.colors.Red },
+      [3] = { foreground = Screen.colors.Blue, underline = true },
+      [4] = { foreground = Screen.colors.Red, underline = true },
+      [5] = { bold = true },
+    })
+    exec([[
+      hi! Comment guibg=NONE guifg=Blue gui=NONE guisp=NONE
+      hi! SpellBad guibg=NONE guifg=Red gui=NONE guisp=NONE
+      hi! Visual guibg=NONE guifg=NONE gui=underline guisp=NONE
+      syn match Comment "//.*"
+      call setline(1, '// Here is a misspeld word.')
+      set spell
+    ]])
+    screen:expect([[
+      {1:^// Here is a }{2:misspeld}{1: word.}                |
+      {0:~                                          }|
+                                                 |
+    ]])
+    feed('V')
+    screen:expect([[
+      {1:^/}{3:/ Here is a }{4:misspeld}{3: word.}                |
+      {0:~                                          }|
+      {5:-- VISUAL LINE --}                          |
+    ]])
+  end)
 end)