vim-patch:9.0.0086: tabline is not redrawn when entering command line

Problem:    Tabline is not redrawn when entering command line.
Solution:   Set "redraw_tabline". (closes vim/vim#10771)
https://github.com/vim/vim/commit/6791adca53981666f0cf23e264e102b795224044

3 files changed, 49 insertions, 2 deletions

diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index 04334d4fa0..906e52f183 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -880,6 +880,12 @@ static uint8_t *command_line_enter(int firstc, long count, int indent, bool init
         found_one = true;
       }
     }
+
+    if (*p_tal != NUL) {
+      redraw_tabline = true;
+      found_one = true;
+    }
+
     if (found_one) {
       redraw_statuslines();
     }
diff --git a/src/nvim/testdir/test_cmdline.vim b/src/nvim/testdir/test_cmdline.vim
index 276bb7fb71..a0907d79ac 100644
--- a/src/nvim/testdir/test_cmdline.vim
+++ b/src/nvim/testdir/test_cmdline.vim
@@ -1846,4 +1846,20 @@ func Test_long_error_message()
   silent! norm Q00000000000000     000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000                                                                                                                                                                                                                        
 endfunc
 
+func Test_cmdline_redraw_tabline()
+  CheckRunVimInTerminal
+
+  let lines =<< trim END
+      set showtabline=2
+      autocmd CmdlineEnter * set tabline=foo
+  END
+  call writefile(lines, 'Xcmdline_redraw_tabline')
+  let buf = RunVimInTerminal('-S Xcmdline_redraw_tabline', #{rows: 6})
+  call term_sendkeys(buf, ':')
+  call WaitForAssert({-> assert_match('^foo', term_getline(buf, 1))})
+
+  call StopVimInTerminal(buf)
+  call delete('Xcmdline_redraw_tabline')
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/test/functional/legacy/cmdline_spec.lua b/test/functional/legacy/cmdline_spec.lua
index d8d849271b..cf02636890 100644
--- a/test/functional/legacy/cmdline_spec.lua
+++ b/test/functional/legacy/cmdline_spec.lua
@@ -3,11 +3,12 @@ local Screen = require('test.functional.ui.screen')
 local clear = helpers.clear
 local feed = helpers.feed
 local feed_command = helpers.feed_command
-local source = helpers.source
+local exec = helpers.exec
 
 describe('cmdline', function()
   before_each(clear)
 
+  -- oldtest: Test_cmdlineclear_tabenter()
   it('is cleared when switching tabs', function()
     local screen = Screen.new(30, 10)
     screen:attach()
@@ -91,10 +92,11 @@ describe('cmdline', function()
     ]])
   end)
 
+  -- oldtest: Test_verbose_option()
   it('prints every executed Ex command if verbose >= 16', function()
     local screen = Screen.new(60, 12)
     screen:attach()
-    source([[
+    exec([[
       command DoSomething echo 'hello' |set ts=4 |let v = '123' |echo v
       call feedkeys("\r", 't') " for the hit-enter prompt
       set verbose=20
@@ -115,4 +117,27 @@ describe('cmdline', function()
       Press ENTER or type command to continue^                     |
     ]])
   end)
+
+  -- oldtest: Test_cmdline_redraw_tabline()
+  it('tabline is redrawn on entering cmdline', function()
+    local screen = Screen.new(30, 6)
+    screen:set_default_attr_ids({
+      [0] = {bold = true, foreground = Screen.colors.Blue},  -- NonText
+      [1] = {reverse = true},  -- TabLineFill
+    })
+    screen:attach()
+    exec([[
+      set showtabline=2
+      autocmd CmdlineEnter * set tabline=foo
+    ]])
+    feed(':')
+    screen:expect([[
+      {1:foo                           }|
+                                    |
+      {0:~                             }|
+      {0:~                             }|
+      {0:~                             }|
+      :^                             |
+    ]])
+  end)
 end)