check for empty post before asking for confirmation

before this change, BBJ would give the big "You are posting
anonymously!" warning even if the post body was empty (say, because you
accidentally started a post and closed the editor immediately). only
after confirming that you _really_ wanted to post anonymously would it
notice that, hey, the post body is empty and discard the post.

it makes more sense to do the checks the other way around.

clients/urwid/main.py

@@ -1982,6 +1982,18 @@ class ExternalEditor(urwid.Terminal):
 
 
     def exterminate(self, *_, anon_confirmed=False):
+        # close the editor and grab the post body
+        app.close_editor()
+        with open(self.path) as _:
+            body = _.read().strip()
+        os.remove(self.path)
+
+        # make sure its not empty
+        if not body or re.search("^>>[0-9]+$", body):
+            app.temp_footer_message("EMPTY POST DISCARDED")
+            return
+
+        # are we anonymous? check if the user wants to log in first
         if app.prefs["confirm_anon"] \
            and not anon_confirmed    \
            and app.network.user["user_name"] == "anonymous":
@@ -2020,12 +2032,7 @@ class ExternalEditor(urwid.Terminal):
                 log_in(True)
             app.loop.start()
 
-        app.close_editor()
-        with open(self.path) as _:
-            body = _.read().strip()
-        os.remove(self.path)
-
-        if body and not re.search("^>>[0-9]+$", body):
+        # ok; do the post
         self.params.update({"body": body})
         app.network.request(self.endpoint, **self.params)
         if self.endpoint == "edit_post":
@@ -2039,8 +2046,6 @@ class ExternalEditor(urwid.Terminal):
         else:
             app.last_pos = None
             app.index()
-        else:
-            app.temp_footer_message("EMPTY POST DISCARDED")
 
 
     def keypress(self, size, key):