vim-patch:8.1.1192: mode is not cleared when leaving Insert mode with mapped Esc

Problem:    Mode is not cleared when leaving Insert mode with mapped Esc.
Solution:   Clear the mode when redraw_cmdline is set. (closes vim/vim#4269)
4c25bd785a

src/nvim/globals.h

@@ -145,6 +145,7 @@ EXTERN int vgetc_char INIT(= 0);
 EXTERN int cmdline_row;
 
 EXTERN bool redraw_cmdline INIT(= false);          // cmdline must be redrawn
+EXTERN bool redraw_mode INIT(= false);             // mode must be redrawn
 EXTERN bool clear_cmdline INIT(= false);           // cmdline must be cleared
 EXTERN bool mode_displayed INIT(= false);          // mode is being displayed
 EXTERN int cmdline_star INIT(= false);             // cmdline is encrypted

src/nvim/screen.c

@@ -591,7 +591,7 @@ int update_screen(int type)
 
   // Clear or redraw the command line.  Done last, because scrolling may
   // mess up the command line.
-  if (clear_cmdline || redraw_cmdline) {
+  if (clear_cmdline || redraw_cmdline || redraw_mode) {
     showmode();
   }
 
@@ -5828,18 +5828,19 @@ bool skip_showmode(void)
   // Call char_avail() only when we are going to show something, because it
   // takes a bit of time.  redrawing() may also call char_avail().
   if (global_busy || msg_silent != 0 || !redrawing() || (char_avail() && !KeyTyped)) {
-    redraw_cmdline = true;  // show mode later
+    redraw_mode = true;  // show mode later
     return true;
   }
   return false;
 }
 
-// Show the current mode and ruler.
-//
-// If clear_cmdline is true, clear the rest of the cmdline.
-// If clear_cmdline is false there may be a message there that needs to be
-// cleared only if a mode is shown.
-// Return the length of the message (0 if no message).
+/// Show the current mode and ruler.
+///
+/// If clear_cmdline is true, clear the rest of the cmdline.
+/// If clear_cmdline is false there may be a message there that needs to be
+/// cleared only if a mode is shown.
+/// If redraw_mode is true show or clear the mode.
+/// @return the length of the message (0 if no message).
 int showmode(void)
 {
   bool need_clear;
@@ -5998,7 +5999,7 @@ int showmode(void)
     }
 
     mode_displayed = true;
-    if (need_clear || clear_cmdline) {
+    if (need_clear || clear_cmdline || redraw_mode) {
       msg_clr_eos();
     }
     msg_didout = false;                 // overwrite this message
@@ -6010,6 +6011,9 @@ int showmode(void)
   } else if (clear_cmdline && msg_silent == 0) {
     // Clear the whole command line.  Will reset "clear_cmdline".
     msg_clr_cmdline();
+  } else if (redraw_mode) {
+    msg_pos_mode();
+    msg_clr_eos();
   }
 
   // NB: also handles clearing the showmode if it was empty or disabled
@@ -6027,6 +6031,7 @@ int showmode(void)
     win_redr_ruler(last, true);
   }
   redraw_cmdline = false;
+  redraw_mode = false;
   clear_cmdline = false;
 
   return length;

src/nvim/testdir/test_messages.vim

@@ -126,6 +126,34 @@ func Test_mode_message_at_leaving_insert_by_ctrl_c()
   call delete(testfile)
 endfunc
 
+func Test_mode_message_at_leaving_insert_with_esc_mapped()
+  if !has('terminal') || has('gui_running')
+    return
+  endif
+
+  " Set custom statusline built by user-defined function.
+  let testfile = 'Xtest.vim'
+  call writefile([
+        \ 'set laststatus=2',
+        \ 'inoremap <Esc> <Esc>00',
+        \ ], 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*$', term_getline(buf, rows))})
+  call term_sendkeys(buf, "\<Esc>")
+  call WaitForAssert({-> assert_match('^\s*$', 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
+
 func Test_echospace()
   set noruler noshowcmd laststatus=1
   call assert_equal(&columns - 1, v:echospace)

test/functional/legacy/messages_spec.lua

@@ -376,6 +376,32 @@ describe('messages', function()
                                                 |
       ]])
     end)
+
+    -- oldtest: Test_mode_message_at_leaving_insert_with_esc_mapped()
+    it('leaving Insert mode with ESC in the middle of a mapping vim-patch:8.1.1192', function()
+      exec([[
+        set laststatus=2
+        inoremap <Esc> <Esc>00
+      ]])
+      feed('i')
+      screen:expect([[
+        ^                                        |
+        {1:~                                       }|
+        {1:~                                       }|
+        {1:~                                       }|
+        {3:[No Name]                               }|
+        {2:-- INSERT --}                            |
+      ]])
+      feed('<Esc>')
+      screen:expect([[
+        ^                                        |
+        {1:~                                       }|
+        {1:~                                       }|
+        {1:~                                       }|
+        {3:[No Name]                               }|
+                                                |
+      ]])
+    end)
   end)
 
   -- oldtest: Test_ask_yesno()