vim-patch:9.0.2102: matchparen highlight not cleared in completion mode (#26019)

Problem:  matchparen highlight not cleared in completion mode
Solution: Clear matchparen highlighting in completion mode

Remove hard-coded hack in insexpand.c to clear the :3match before
displaying the completion menu.

Add a test for matchparen highlighting. While at it, move all test tests
related to the matchparen plugin into a separate test file.

closes: vim/vim#13493
closes: vim/vim#13524

https://github.com/vim/vim/commit/9588666360e94de3ff58d4bc79aa9148fbf5fc44

Co-authored-by: Christian Brabandt <cb@256bit.org>

2 files changed, 116 insertions, 73 deletions

diff --git a/test/functional/legacy/display_spec.lua b/test/functional/legacy/display_spec.lua
index 89120baea9..9c6f521882 100644
--- a/test/functional/legacy/display_spec.lua
+++ b/test/functional/legacy/display_spec.lua
@@ -9,34 +9,6 @@ local command = helpers.command
 describe('display', function()
   before_each(clear)
 
-  -- oldtest: Test_visual_block_scroll()
-  it('redraws properly after scrolling with matchparen loaded and scrolloff=1', function()
-    local screen = Screen.new(30, 7)
-    screen:attach()
-    screen:set_default_attr_ids({
-      [1] = {bold = true},
-      [2] = {background = Screen.colors.LightGrey},
-    })
-
-    exec([[
-      source $VIMRUNTIME/plugin/matchparen.vim
-      set scrolloff=1
-      call setline(1, ['a', 'b', 'c', 'd', 'e', '', '{', '}', '{', 'f', 'g', '}'])
-      call cursor(5, 1)
-    ]])
-
-    feed('V<c-d><c-d>')
-    screen:expect([[
-      {2:{}                             |
-      {2:}}                             |
-      {2:{}                             |
-      {2:f}                             |
-      ^g                             |
-      }                             |
-      {1:-- VISUAL LINE --}             |
-    ]])
-  end)
-
   -- oldtest: Test_display_scroll_at_topline()
   it('scroll when modified at topline vim-patch:8.2.1488', function()
     local screen = Screen.new(20, 4)
@@ -86,51 +58,6 @@ describe('display', function()
     ]])
   end)
 
-  -- oldtest: Test_matchparen_clear_highlight()
-  it('matchparen highlight is cleared when switching buffer', function()
-    local screen = Screen.new(20, 5)
-    screen:set_default_attr_ids({
-      [0] = {bold = true, foreground = Screen.colors.Blue},
-      [1] = {background = Screen.colors.Cyan},
-    })
-    screen:attach()
-
-    local screen1 = [[
-      {1:^()}                  |
-      {0:~                   }|
-      {0:~                   }|
-      {0:~                   }|
-                          |
-    ]]
-    local screen2 = [[
-      ^aa                  |
-      {0:~                   }|
-      {0:~                   }|
-      {0:~                   }|
-                          |
-    ]]
-
-    exec([[
-      source $VIMRUNTIME/plugin/matchparen.vim
-      set hidden
-      call setline(1, ['()'])
-      normal 0
-    ]])
-    screen:expect(screen1)
-
-    exec([[
-      enew
-      exe "normal iaa\<Esc>0"
-    ]])
-    screen:expect(screen2)
-
-    feed('<C-^>')
-    screen:expect(screen1)
-
-    feed('<C-^>')
-    screen:expect(screen2)
-  end)
-
   local function run_test_display_lastline(euro)
     local screen = Screen.new(75, 10)
     screen:set_default_attr_ids({
diff --git a/test/functional/legacy/matchparen_spec.lua b/test/functional/legacy/matchparen_spec.lua
new file mode 100644
index 0000000000..22d9247698
--- /dev/null
+++ b/test/functional/legacy/matchparen_spec.lua
@@ -0,0 +1,116 @@
+local helpers = require('test.functional.helpers')(after_each)
+
+local Screen = require('test.functional.ui.screen')
+local clear = helpers.clear
+local exec = helpers.exec
+local feed = helpers.feed
+
+describe('matchparen', function()
+  before_each(clear)
+
+  -- oldtest: Test_visual_block_scroll()
+  it('redraws properly after scrolling with scrolloff=1', function()
+    local screen = Screen.new(30, 7)
+    screen:attach()
+    screen:set_default_attr_ids({
+      [1] = {bold = true},
+      [2] = {background = Screen.colors.LightGrey},
+    })
+
+    exec([[
+      source $VIMRUNTIME/plugin/matchparen.vim
+      set scrolloff=1
+      call setline(1, ['a', 'b', 'c', 'd', 'e', '', '{', '}', '{', 'f', 'g', '}'])
+      call cursor(5, 1)
+    ]])
+
+    feed('V<c-d><c-d>')
+    screen:expect([[
+      {2:{}                             |
+      {2:}}                             |
+      {2:{}                             |
+      {2:f}                             |
+      ^g                             |
+      }                             |
+      {1:-- VISUAL LINE --}             |
+    ]])
+  end)
+
+  -- oldtest: Test_matchparen_clear_highlight()
+  it('matchparen highlight is cleared when switching buffer', function()
+    local screen = Screen.new(20, 5)
+    screen:set_default_attr_ids({
+      [0] = {bold = true, foreground = Screen.colors.Blue},
+      [1] = {background = Screen.colors.Cyan},
+    })
+    screen:attach()
+
+    local screen1 = [[
+      {1:^()}                  |
+      {0:~                   }|
+      {0:~                   }|
+      {0:~                   }|
+                          |
+    ]]
+    local screen2 = [[
+      ^aa                  |
+      {0:~                   }|
+      {0:~                   }|
+      {0:~                   }|
+                          |
+    ]]
+
+    exec([[
+      source $VIMRUNTIME/plugin/matchparen.vim
+      set hidden
+      call setline(1, ['()'])
+      normal 0
+    ]])
+    screen:expect(screen1)
+
+    exec([[
+      enew
+      exe "normal iaa\<Esc>0"
+    ]])
+    screen:expect(screen2)
+
+    feed('<C-^>')
+    screen:expect(screen1)
+
+    feed('<C-^>')
+    screen:expect(screen2)
+  end)
+
+  -- oldtest: Test_matchparen_pum_clear()
+  it('is cleared when completion popup is shown', function()
+    local screen = Screen.new(30, 9)
+    screen:attach()
+    screen:set_default_attr_ids({
+      [0] = {bold = true, foreground = Screen.colors.Blue};
+      [1] = {background = Screen.colors.Plum1};
+      [2] = {background = Screen.colors.Grey};
+      [3] = {bold = true};
+      [4] = {bold = true, foreground = Screen.colors.SeaGreen};
+    })
+
+    exec([[
+      source $VIMRUNTIME/plugin/matchparen.vim
+      set completeopt=menuone
+      call setline(1, ['aa', 'aaa', 'aaaa', '(a)'])
+      call cursor(4, 3)
+    ]])
+
+    feed('i<C-X><C-N><C-N>')
+    screen:expect{grid=[[
+      aa                            |
+      aaa                           |
+      aaaa                          |
+      (aaa^)                         |
+      {1: aa             }{0:              }|
+      {2: aaa            }{0:              }|
+      {1: aaaa           }{0:              }|
+      {0:~                             }|
+      {3:-- }{4:match 2 of 3}               |
+    ]]}
+  end)
+end)