From 595c1a724af9fe93d4ff1df7d5c47e4c9c31a7a6 Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Mon, 28 Mar 2022 06:45:15 +0800
Subject: perf: only redraw concealed line if cursor has moved horizontally

Building upon #17889, this moves conceal redrawing logic into move.c, so
that concealed line is only redrawn if cursor has moved horizontally.
---
 test/functional/ui/syntax_conceal_spec.lua | 53 +++++++++++++++++++++++++++++-
 1 file changed, 52 insertions(+), 1 deletion(-)

(limited to 'test')

diff --git a/test/functional/ui/syntax_conceal_spec.lua b/test/functional/ui/syntax_conceal_spec.lua
index 4e1852162f..92e5a5dd94 100644
--- a/test/functional/ui/syntax_conceal_spec.lua
+++ b/test/functional/ui/syntax_conceal_spec.lua
@@ -3,6 +3,7 @@ local Screen = require('test.functional.ui.screen')
 local clear, feed, command = helpers.clear, helpers.feed, helpers.command
 local eq = helpers.eq
 local insert = helpers.insert
+local poke_eventloop = helpers.poke_eventloop
 
 describe('Screen', function()
   local screen
@@ -911,7 +912,57 @@ describe('Screen', function()
       {0:~                                                    }|
                                                            |
     ]]}
-    eq(grid_lines, {{2, 0, {{'c', 0, 3}}}})
+    eq({{2, 0, {{'c', 0, 3}}}}, grid_lines)
+  end)
+
+  it('K_EVENT should not cause extra redraws with concealcursor #13196', function()
+    command('set conceallevel=1')
+    command('set concealcursor=nv')
+    command('set redrawdebug+=nodelta')
+
+    insert([[
+    aaa
+    bbb
+    ccc
+    ]])
+    screen:expect{grid=[[
+      aaa                                                  |
+      bbb                                                  |
+      ccc                                                  |
+      ^                                                     |
+      {0:~                                                    }|
+      {0:~                                                    }|
+      {0:~                                                    }|
+      {0:~                                                    }|
+      {0:~                                                    }|
+                                                           |
+    ]]}
+
+    -- XXX: hack to get notifications, and check only a single line is
+    --      updated.  Could use next_msg() also.
+    local orig_handle_grid_line = screen._handle_grid_line
+    local grid_lines = {}
+    function screen._handle_grid_line(self, grid, row, col, items)
+      table.insert(grid_lines, {row, col, items})
+      orig_handle_grid_line(self, grid, row, col, items)
+    end
+    feed('k')
+    screen:expect{grid=[[
+      aaa                                                  |
+      bbb                                                  |
+      ^ccc                                                  |
+                                                           |
+      {0:~                                                    }|
+      {0:~                                                    }|
+      {0:~                                                    }|
+      {0:~                                                    }|
+      {0:~                                                    }|
+                                                           |
+    ]]}
+    eq({{2, 0, {{'c', 0, 3}}}}, grid_lines)
+    poke_eventloop()  -- causes K_EVENT key
+    screen:expect_unchanged()
+    eq({{2, 0, {{'c', 0, 3}}}}, grid_lines)
   end)
 
   -- Copy of Test_cursor_column_in_concealed_line_after_window_scroll in
-- 
cgit