vim-patch:8.2.0911: crash when opening a buffer for the cmdline window fails

Problem:    Crash when opening a buffer for the cmdline window fails. (Chris
            Barber)
Solution:   Check do_ecmd() succeeds.  Reset got_int if "q" was used at the
            more prompt. (closes vim/vim#6211)
https://github.com/vim/vim/commit/9b7cce28d568f0622d77c6c9878c2d4770c3b164

Make code match latest Vim instead.

1 files changed, 13 insertions, 3 deletions

diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index afec21a86f..ce4930d33e 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -4073,17 +4073,27 @@ static int open_cmdwin(void)
     ga_clear(&winsizes);
     return K_IGNORE;
   }
+  // Don't let quitting the More prompt make this fail.
+  got_int = false;
+
+  // Set "cmdwin_type" before any autocommands may mess things up.
   cmdwin_type = get_cmdline_type();
   cmdwin_level = ccline.level;
 
   // Create empty command-line buffer.
-  buf_open_scratch(0, _("[Command Line]"));
+  if (buf_open_scratch(0, _("[Command Line]")) == FAIL) {
+    // Some autocommand messed it up?
+    win_close(curwin, true, false);
+    ga_clear(&winsizes);
+    cmdwin_type = 0;
+    return Ctrl_C;
+  }
   // Command-line buffer has bufhidden=wipe, unlike a true "scratch" buffer.
   set_option_value_give_err("bh", 0L, "wipe", OPT_LOCAL);
-  curwin->w_p_rl = cmdmsg_rl;
-  cmdmsg_rl = false;
   curbuf->b_p_ma = true;
   curwin->w_p_fen = false;
+  curwin->w_p_rl = cmdmsg_rl;
+  cmdmsg_rl = false;
 
   // Don't allow switching to another buffer.
   curbuf->b_ro_locked++;