vim-patch:8.1.0822: peeking and flushing output slows down execution (#25629)

Problem:    Peeking and flushing output slows down execution.
Solution:   Do not update the mode message when global_busy is set.  Do not
            flush when only peeking for a character. (Ken Takata)

cb574f4154

src/nvim/drawline.c

@@ -3287,5 +3287,5 @@ static void win_put_linebuf(win_T *wp, int row, int coloff, int endcol, int clea
   }
 
   grid_adjust(&grid, &row, &coloff);
-  grid_put_linebuf(grid, row, coloff, 0, endcol, clear_width, wp->w_p_rl, bg_attr, wrap, false);
+  grid_put_linebuf(grid, row, coloff, 0, endcol, clear_width, wp->w_p_rl, bg_attr, wrap);
 }

src/nvim/getchar.c

@@ -2861,8 +2861,10 @@ int inchar(uint8_t *buf, int maxlen, long wait_time)
     }
 
     // Always flush the output characters when getting input characters
-    // from the user.
+    // from the user and not just peeking.
+    if (wait_time == -1L || wait_time > 10L) {
       ui_flush();
+    }
 
     // Fill up to a third of the buffer, because each character may be
     // tripled below.

src/nvim/grid.c

@@ -481,11 +481,8 @@ void grid_line_flush(void)
     return;
   }
 
-  int row = grid_line_row;
-
-  bool invalid_row = grid != &default_grid && grid_invalid_row(grid, row) && grid_line_first == 0;
-  grid_put_linebuf(grid, row, grid_line_coloff, grid_line_first, grid_line_last, grid_line_last,
-                   false, 0, false, invalid_row);
+  grid_put_linebuf(grid, grid_line_row, grid_line_coloff, grid_line_first, grid_line_last,
+                   grid_line_last, false, 0, false);
 }
 
 /// flush grid line but only if on a valid row
@@ -620,7 +617,7 @@ static int grid_char_needs_redraw(ScreenGrid *grid, int col, size_t off_to, int
 /// If "wrap" is true, then hint to the UI that "row" contains a line
 /// which has wrapped into the next row.
 void grid_put_linebuf(ScreenGrid *grid, int row, int coloff, int col, int endcol, int clear_width,
-                      bool rl, int bg_attr, bool wrap, bool invalid_row)
+                      bool rl, int bg_attr, bool wrap)
 {
   bool redraw_next;                         // redraw_this for next character
   bool clear_next = false;
@@ -639,6 +636,7 @@ void grid_put_linebuf(ScreenGrid *grid, int row, int coloff, int col, int endcol
     return;
   }
 
+  bool invalid_row = grid != &default_grid && grid_invalid_row(grid, row) && col == 0;
   size_t off_to = grid->line_offset[row] + (size_t)coloff;
   const size_t max_off_to = grid->line_offset[row] + (size_t)grid->cols;
 

test/functional/lua/ui_event_spec.lua

@@ -77,8 +77,7 @@ describe('vim.ui_attach', function()
     }
 
     feed '<c-y>'
-    -- There is an intermediate state where the 'showmode' message disappears.
-    screen:expect_unchanged(true)
+    screen:expect_unchanged()
     expect_events {
        { "popupmenu_hide" };
     }

test/functional/ui/decorations_spec.lua

@@ -1775,30 +1775,36 @@ describe('extmark decorations', function()
     ]])
 
     -- When only one highlight group has an underline attribute, it should always take effect.
+    for _, d in ipairs({-5, 5}) do
       meths.buf_clear_namespace(0, ns, 0, -1)
-    meths.buf_set_extmark(0, ns, 0, 0, { end_col = 9, hl_group = 'TestUL', priority = 20 })
-    meths.buf_set_extmark(0, ns, 0, 3, { end_col = 6, hl_group = 'TestBold', priority = 30 })
+      screen:expect([[
+        aaabbbaa^a                                         |
+        {0:~                                                 }|
+                                                          |
+      ]])
+      meths.buf_set_extmark(0, ns, 0, 0, { end_col = 9, hl_group = 'TestUL', priority = 25 + d })
+      meths.buf_set_extmark(0, ns, 0, 3, { end_col = 6, hl_group = 'TestBold', priority = 25 - d })
       screen:expect([[
         {1:aaa}{5:bbb}{1:aa^a}                                         |
         {0:~                                                 }|
                                                           |
       ]])
+    end
+    for _, d in ipairs({-5, 5}) do
       meths.buf_clear_namespace(0, ns, 0, -1)
-    meths.buf_set_extmark(0, ns, 0, 0, { end_col = 9, hl_group = 'TestUL', priority = 30 })
-    meths.buf_set_extmark(0, ns, 0, 3, { end_col = 6, hl_group = 'TestBold', priority = 20 })
-    screen:expect_unchanged(true)
-    meths.buf_clear_namespace(0, ns, 0, -1)
-    meths.buf_set_extmark(0, ns, 0, 0, { end_col = 9, hl_group = 'TestUC', priority = 20 })
-    meths.buf_set_extmark(0, ns, 0, 3, { end_col = 6, hl_group = 'TestBold', priority = 30 })
+      screen:expect([[
+        aaabbbaa^a                                         |
+        {0:~                                                 }|
+                                                          |
+      ]])
+      meths.buf_set_extmark(0, ns, 0, 0, { end_col = 9, hl_group = 'TestUC', priority = 25 + d })
+      meths.buf_set_extmark(0, ns, 0, 3, { end_col = 6, hl_group = 'TestBold', priority = 25 - d })
       screen:expect([[
         {2:aaa}{6:bbb}{2:aa^a}                                         |
         {0:~                                                 }|
                                                           |
       ]])
-    meths.buf_clear_namespace(0, ns, 0, -1)
-    meths.buf_set_extmark(0, ns, 0, 0, { end_col = 9, hl_group = 'TestUC', priority = 30 })
-    meths.buf_set_extmark(0, ns, 0, 3, { end_col = 6, hl_group = 'TestBold', priority = 20 })
-    screen:expect_unchanged(true)
+    end
   end)
 
   it('highlight is combined with syntax and sign linehl #20004', function()

test/functional/ui/float_spec.lua

@@ -9284,9 +9284,11 @@ describe('float window', function()
       end
 
       -- Also test with global NormalNC highlight
-      meths.set_option_value('winhighlight', '', {win = win})
-      command('hi link NormalNC Visual')
-      screen:expect_unchanged(true)
+      exec_lua([[
+        vim.api.nvim_set_option_value('winhighlight', '', {win = ...})
+        vim.api.nvim_set_hl(0, 'NormalNC', {link = 'Visual'})
+      ]], win)
+      screen:expect_unchanged()
       command('hi clear NormalNC')
 
       command('hi SpecialRegion guifg=Red blend=0')

test/functional/ui/fold_spec.lua

@@ -169,10 +169,10 @@ describe("folded lines", function()
       end
       -- CursorLine is applied correctly with screenrow motions #22232
       feed("jgk")
-      screen:expect_unchanged(true)
+      screen:expect_unchanged()
       -- CursorLine is applied correctly when closing a fold when cursor is not at fold start
       feed("zo4Gzc")
-      screen:expect_unchanged(true)
+      screen:expect_unchanged()
       command("set cursorlineopt=line")
       if multigrid then
         screen:expect([[

test/functional/ui/inccommand_spec.lua

@@ -2929,7 +2929,16 @@ it(':substitute with inccommand, allows :redraw before first separator is typed
   meths.open_win(float_buf, false, {
     relative = 'editor', height = 1, width = 5, row = 3, col = 0, focusable = false,
   })
-  feed(':%s')
+  feed(':')
+  screen:expect([[
+    foo bar baz                   |
+    bar baz fox                   |
+    bar foo baz                   |
+    {16:     }{15:                         }|
+    {15:~                             }|
+    :^                             |
+  ]])
+  feed('%s')
   screen:expect([[
     foo bar baz                   |
     bar baz fox                   |

test/functional/ui/options_spec.lua

@@ -69,6 +69,9 @@ describe('UI receives option updates', function()
       eq({'mouse_on'}, evs)
     end)
     command("set mouse=")
+    screen:expect(function()
+      eq({'mouse_on', 'mouse_off'}, evs)
+    end)
     command("set mouse&")
     screen:expect(function()
       eq({'mouse_on', 'mouse_off', 'mouse_on'}, evs)

test/functional/ui/searchhl_spec.lua

@@ -337,7 +337,7 @@ describe('search highlighting', function()
     ]])
     feed('/foo')
     helpers.poke_eventloop()
-    screen:sleep(0)
+    screen:sleep(100)
     screen:expect_unchanged()
   end)