Reset stop_insert_mode in terminal_enter rather than terminal_check

Problem: Using `:stopinsert` while in normal mode in a terminal buffer
prevents neovim from entering insert mode.

Solution: Move `stop_insert_mode = false` from terminal_check to
terminal_enter to be consistent with edit.c, as suggested by bfredl in
 #9889.

Closes https://github.com/neovim/neovim/issues/9889.

1 files changed, 9 insertions, 0 deletions

diff --git a/test/functional/terminal/ex_terminal_spec.lua b/test/functional/terminal/ex_terminal_spec.lua
index ca5737db7f..f3849709e3 100644
--- a/test/functional/terminal/ex_terminal_spec.lua
+++ b/test/functional/terminal/ex_terminal_spec.lua
@@ -106,6 +106,15 @@ describe(':terminal', function()
     command('stopinsert')
     eq({ blocking=false, mode='n' }, nvim('get_mode'))
   end)
+
+  it(':stopinsert in normal mode doesn\'t break insert mode #9889', function()
+    command(':terminal')
+    eq({ blocking=false, mode='n' }, nvim('get_mode'))
+    command(':stopinsert')
+    eq({ blocking=false, mode='n' }, nvim('get_mode'))
+    feed('a')
+    eq({ blocking=false, mode='t' }, nvim('get_mode'))
+  end)
 end)
 
 describe(':terminal (with fake shell)', function()