vim-patch:9.0.1634: message is cleared when removing mode message

Problem:    Message is cleared when removing mode message (Gary Johnson).
Solution:   Do not clear the command line after displaying a message.

https://github.com/vim/vim/commit/800cdbb7caeb5dd4379c6cb071bb12391f20bcf3

Co-authored-by: Bram Moolenaar <Bram@vim.org>

4 files changed, 84 insertions, 1 deletions

diff --git a/src/nvim/message.c b/src/nvim/message.c
index 1cb4a3cbf4..d0b128c568 100644
--- a/src/nvim/message.c
+++ b/src/nvim/message.c
@@ -1560,6 +1560,13 @@ int msg_outtrans_len_attr(const char *msgstr, int len, int attr)
     attr &= ~MSG_HIST;
   }
 
+  // When drawing over the command line no need to clear it later or remove
+  // the mode message.
+  if (msg_row == cmdline_row && msg_col == 0) {
+    clear_cmdline = false;
+    mode_displayed = false;
+  }
+
   // If the string starts with a composing character first draw a space on
   // which the composing char can be drawn.
   if (utf_iscomposing(utf_ptr2char(msgstr))) {
diff --git a/test/functional/legacy/messages_spec.lua b/test/functional/legacy/messages_spec.lua
index 794676153c..0a4d418e9c 100644
--- a/test/functional/legacy/messages_spec.lua
+++ b/test/functional/legacy/messages_spec.lua
@@ -49,6 +49,54 @@ describe('messages', function()
     ]])
   end)
 
+  -- oldtest: Test_message_not_cleared_after_mode()
+  it('clearing mode does not remove message', function()
+    screen = Screen.new(60, 10)
+    screen:set_default_attr_ids({
+      [0] = {bold = true, foreground = Screen.colors.Blue},  -- NonText
+    })
+    screen:attach()
+    exec([[
+      nmap <silent> gx :call DebugSilent('normal')<CR>
+      vmap <silent> gx :call DebugSilent('visual')<CR>
+      function DebugSilent(arg)
+          echomsg "from DebugSilent" a:arg
+      endfunction
+      set showmode
+      set cmdheight=1
+      call setline(1, ['one', 'two', 'three'])
+    ]])
+
+    feed('gx')
+    screen:expect([[
+      ^one                                                         |
+      two                                                         |
+      three                                                       |
+      {0:~                                                           }|
+      {0:~                                                           }|
+      {0:~                                                           }|
+      {0:~                                                           }|
+      {0:~                                                           }|
+      {0:~                                                           }|
+      from DebugSilent normal                                     |
+    ]])
+
+    -- removing the mode message used to also clear the intended message
+    feed('vEgx')
+    screen:expect([[
+      ^one                                                         |
+      two                                                         |
+      three                                                       |
+      {0:~                                                           }|
+      {0:~                                                           }|
+      {0:~                                                           }|
+      {0:~                                                           }|
+      {0:~                                                           }|
+      {0:~                                                           }|
+      from DebugSilent visual                                     |
+    ]])
+  end)
+
   describe('more prompt', function()
     before_each(function()
       command('set more')
diff --git a/test/functional/terminal/tui_spec.lua b/test/functional/terminal/tui_spec.lua
index 7723b6c7e7..b1836f2e4d 100644
--- a/test/functional/terminal/tui_spec.lua
+++ b/test/functional/terminal/tui_spec.lua
@@ -2475,7 +2475,7 @@ describe("TUI as a client", function()
 
     -- grid smaller than containing terminal window is cleared properly
     feed_data(":call setline(1,['a'->repeat(&columns)]->repeat(&lines))\n")
-    feed_data("0:set lines=2\n")
+    feed_data("0:set lines=3\n")
     screen_server:expect{grid=[[
       {1:a}aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa|
       {5:[No Name] [+]                                     }|
diff --git a/test/old/testdir/test_messages.vim b/test/old/testdir/test_messages.vim
index a20571807b..766b04d154 100644
--- a/test/old/testdir/test_messages.vim
+++ b/test/old/testdir/test_messages.vim
@@ -341,6 +341,34 @@ func Test_message_more_scrollback()
   call StopVimInTerminal(buf)
 endfunc
 
+func Test_message_not_cleared_after_mode()
+  CheckRunVimInTerminal
+
+  let lines =<< trim END
+      nmap <silent> gx :call DebugSilent('normal')<CR>
+      vmap <silent> gx :call DebugSilent('visual')<CR>
+      function DebugSilent(arg)
+          echomsg "from DebugSilent" a:arg
+      endfunction
+      set showmode
+      set cmdheight=1
+      call setline(1, ['one', 'two', 'three'])
+  END
+  call writefile(lines, 'XmessageMode', 'D')
+  let buf = RunVimInTerminal('-S XmessageMode', {'rows': 10})
+
+  call term_sendkeys(buf, 'gx')
+  call TermWait(buf)
+  call VerifyScreenDump(buf, 'Test_message_not_cleared_after_mode_1', {})
+
+  " removing the mode message used to also clear the intended message
+  call term_sendkeys(buf, 'vEgx')
+  call TermWait(buf)
+  call VerifyScreenDump(buf, 'Test_message_not_cleared_after_mode_2', {})
+
+  call StopVimInTerminal(buf)
+endfunc
+
 " Test verbose message before echo command
 func Test_echo_verbose_system()
   CheckRunVimInTerminal