vim-patch:9.1.1872: Cmdline history not updated when mapping <Up> and <CR> (#36334)

Problem:  Cmdline history not updated when mapping both <Up> and <CR>.
Solution: Consider the command typed when in Cmdline mode and there is
          no pending input (zeertzjq).

Although the existing behavior technically does match documentation, the
"completely come from mappings" part is a bit ambiguous, because one may
argue that the command doesn't completely come from mappings as long as
the user has typed a key in Cmdline mode.  I'm not entirely sure if this
change will cause problems, but it seems unlikely.

fixes: vim/vim#2771
related: neovim/neovim#36256
closes: vim/vim#18607

97b6e8b424

src/nvim/ex_getln.c

@@ -1038,6 +1038,13 @@ static int command_line_check(VimState *state)
                            // that occurs while typing a command should
                            // cause the command not to be executed.
 
+  if (stuff_empty() && typebuf.tb_len == 0) {
+    // There is no pending input from sources other than user input, so
+    // Vim is going to wait for the user to type a key.  Consider the
+    // command line typed even if next key will trigger a mapping.
+    s->some_key_typed = true;
+  }
+
   // Trigger SafeState if nothing is pending.
   may_trigger_safestate(s->xpc.xp_numfiles <= 0);