Add delayed warnings support.

* etc/NEWS: Document `delayed-warnings-list' and `delayed-warnings-hook'.

* lisp/subr.el (display-delayed-warnings): New function.
  (delayed-warnings-hook): New variable.

* src/keyboard.c (Qdelayed_warnings_hook): Define.
  (command_loop_1): Run `delayed-warnings-hook' if Vdelayed_warnings_list
  is non-nil.
  (syms_of_keyboard) <delayed-warnings-hook>: DEFSYM it.
  (syms_of_keyboard) <delayed-warnings-list>: DEFVAR_LISP it.

1 files changed, 19 insertions, 0 deletions

diff --git a/src/keyboard.c b/src/keyboard.c
index fac098ddffd..a94456fce2e 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -267,6 +267,8 @@ static Lisp_Object Qpost_command_hook;
 
 static Lisp_Object Qdeferred_action_function;
 
+static Lisp_Object Qdelayed_warnings_hook;
+
 static Lisp_Object Qinput_method_exit_on_first_char;
 static Lisp_Object Qinput_method_use_echo_area;
 
@@ -1356,6 +1358,10 @@ command_loop_1 (void)
       if (!NILP (echo_area_buffer[0]))
 	resize_echo_area_exactly ();
 
+      /* If there are warnings waiting, process them.  */
+      if (!NILP (Vdelayed_warnings_list))
+        safe_run_hooks (Qdelayed_warnings_hook);
+
       if (!NILP (Vdeferred_action_list))
 	safe_run_hooks (Qdeferred_action_function);
     }
@@ -1573,6 +1579,10 @@ command_loop_1 (void)
       if (!NILP (echo_area_buffer[0]))
 	resize_echo_area_exactly ();
 
+      /* If there are warnings waiting, process them.  */
+      if (!NILP (Vdelayed_warnings_list))
+        safe_run_hooks (Qdelayed_warnings_hook);
+
       safe_run_hooks (Qdeferred_action_function);
 
       /* If there is a prefix argument,
@@ -11498,6 +11508,7 @@ syms_of_keyboard (void)
   DEFSYM (Qpre_command_hook, "pre-command-hook");
   DEFSYM (Qpost_command_hook, "post-command-hook");
   DEFSYM (Qdeferred_action_function, "deferred-action-function");
+  DEFSYM (Qdelayed_warnings_hook, "delayed-warnings-hook");
   DEFSYM (Qfunction_key, "function-key");
   DEFSYM (Qmouse_click, "mouse-click");
   DEFSYM (Qdrag_n_drop, "drag-n-drop");
@@ -12069,6 +12080,14 @@ This function is called with no arguments after each command
 whenever `deferred-action-list' is non-nil.  */);
   Vdeferred_action_function = Qnil;
 
+  DEFVAR_LISP ("delayed-warnings-list", Vdelayed_warnings_list,
+               doc: /* List of warnings to be displayed as soon as possible.
+Each element must be a list (TYPE MESSAGE [LEVEL [BUFFER-NAME]]),
+as per the args of `display-warning' (which see).
+If this variable is non-nil, `delayed-warnings-hook' will be run
+immediately after running `post-command-hook'.  */);
+  Vdelayed_warnings_list = Qnil;
+
   DEFVAR_LISP ("suggest-key-bindings", Vsuggest_key_bindings,
 	       doc: /* *Non-nil means show the equivalent key-binding when M-x command has one.
 The value can be a length of time to show the message for.