patch 8.1.1189: mode is not cleared when leaving Insert mode

Problem:    Mode is not cleared when leaving Insert mode.
Solution:   Clear the mode when got_int is set. (Ozaki Kiichi, closes #4270)
diff --git a/src/testdir/test_messages.vim b/src/testdir/test_messages.vim
index 4bdc136..2d1d6d9 100644
--- a/src/testdir/test_messages.vim
+++ b/src/testdir/test_messages.vim
@@ -1,5 +1,7 @@
 " Tests for :messages, :echomsg, :echoerr
 
+source shared.vim
+
 function Test_messages()
   let oldmore = &more
   try
@@ -92,3 +94,34 @@
   call assert_match("function('<lambda>\\d*')", execute(':echoerr {-> 1234}'))
   call test_ignore_error('RESET')
 endfunc
+
+func Test_mode_message_at_leaving_insert_by_ctrl_c()
+  if !has('terminal') || has('gui_running')
+    return
+  endif
+
+  " Set custom statusline built by user-defined function.
+  let testfile = 'Xtest.vim'
+  call writefile([
+        \ 'func StatusLine() abort',
+        \ '  return ""',
+        \ 'endfunc',
+        \ 'set statusline=%!StatusLine()',
+        \ 'set laststatus=2',
+        \ ], testfile)
+
+  let rows = 10
+  let buf = term_start([GetVimProg(), '--clean', '-S', testfile], {'term_rows': rows})
+  call term_wait(buf, 200)
+  call assert_equal('run', job_status(term_getjob(buf)))
+
+  call term_sendkeys(buf, "i")
+  call WaitForAssert({-> assert_match('^-- INSERT --\s*$', term_getline(buf, rows))})
+  call term_sendkeys(buf, "\<C-C>")
+  call WaitForAssert({-> assert_match('^\s*$', term_getline(buf, rows))})
+
+  call term_sendkeys(buf, ":qall!\<CR>")
+  call WaitForAssert({-> assert_equal('dead', job_status(term_getjob(buf)))})
+  exe buf . 'bwipe!'
+  call delete(testfile)
+endfunc