awful.rules.execute: use delayed_call for emitting request::activate

This is a followup to commit 90fde13, which caused the client not to be
visible during the request::activate callback.

This requires an initial call to `awesome_refresh` before the main loop
to get `awesome.startup` right.

Ref: https://github.com/awesomeWM/awesome/commit/90fde139#commitcomment-9308225

awesome.c

@@ -545,6 +545,10 @@ main(int argc, char **argv)
     g_main_context_set_poll_func(g_main_context_default(), &a_glib_poll);
     gettimeofday(&last_wakeup, NULL);
 
+    /* Do all deferred work now once outside of the loop to get awesome.startup
+     * right. */
+    awesome_refresh();
+
     /* main event loop */
     globalconf.loop = g_main_loop_new(NULL, FALSE);
     g_main_loop_run(globalconf.loop);

lib/awful/rules.lua.in

@@ -12,6 +12,7 @@ local ipairs = ipairs
 local pairs = pairs
 local aclient = require("awful.client")
 local atag = require("awful.tag")
+local timer = require("gears.timer")
 
 --- Apply rules to clients at startup.
 -- awful.rules
@@ -234,7 +235,10 @@ function rules.execute(c, props, callbacks)
     -- Do this at last so we do not erase things done by the focus
     -- signal.
     if props.focus and (type(props.focus) ~= "function" or props.focus(c)) then
-        c:emit_signal('request::activate',"rules")
+        local cb = function(c)
+            c:emit_signal('request::activate', "rules")
+        end
+        timer.delayed_call(cb, c)
     end
 end