# HG changeset patch
# User Richard Laager <rlaager@pidgin.im>
# Date 1112885702 0
# Node ID cabd145237d8545d6b248a41f6f647374179cbd5
# Parent  79d6a09303e7a181ba394bec69f113b044aa3c64
[gaim-migrate @ 12431]
" The following log snippets should explain it: " --rlaager

(20:24:00) rlaager: Regarding the signal handling
conversation the other day... I've written a patch to stop
calling signal handlers and return as soon as we find one
signal handler that returns TRUE to indicate that it's
handled the signal. Is this the right approach?

(20:24:22) Ethan Blanton (Paco-Paco): the trouble is that it's
documented to behave exactly the way it does
(20:24:31) Ethan Blanton (Paco-Paco): so changing it is
notbackwards compatible
(20:24:31) rlaager: I'm talking for HEAD.
(20:24:41) Ethan Blanton (Paco-Paco): oh, I think that's a
good approach, yes
(20:24:53) rlaager: The way I've described is how I
*expected* it to work, having not read the documentation.
(20:25:09) Ethan Blanton (Paco-Paco): I'm convinced
(20:27:04) Stu Tomlinson (nosnilmot): rlaager: this, I
assume, breaks the generic-ness of signals, by assuming
that any that return values return booleans?
(20:27:26) Ethan Blanton (Paco-Paco): please break it
(20:27:33) Ethan Blanton (Paco-Paco): we already have
out-parameters
(20:27:42) rlaager: nosnilmot: from what I can see, the
return type is handled as a (void *)... so I'm checking that
ret_value != NULL
(20:27:57) rlaager: nosnilmot: that's the correct way to do it,
right?
...
(20:29:01) Ethan Blanton (Paco-Paco): allowing a
meaningful return value is an over-engineering
(20:30:07) rlaager: even after this patch, you should be able
to return meaningful return values
(20:30:15) rlaager: it'll just short-circuit on the first handler
that does

committer: Luke Schierer <lschiere@pidgin.im>

diff -r 79d6a09303e7 -r cabd145237d8 src/signals.c
--- a/src/signals.c	Thu Apr 07 14:41:18 2005 +0000
+++ b/src/signals.c	Thu Apr 07 14:55:02 2005 +0000
@@ -512,7 +512,6 @@
 	GaimInstanceData *instance_data;
 	GaimSignalData *signal_data;
 	GaimSignalHandlerData *handler_data;
-	void *ret_val = NULL;
 	GList *l, *l_next;
 	va_list tmp;
 
@@ -536,6 +535,8 @@
 
 	for (l = signal_data->handlers; l != NULL; l = l_next)
 	{
+		void *ret_val = NULL;
+
 		l_next = l->next;
 
 		handler_data = (GaimSignalHandlerData *)l->data;
@@ -552,9 +553,12 @@
 								 handler_data->data, &ret_val);
 		}
 		va_end(tmp);
+
+		if (ret_val != NULL)
+			return ret_val;
 	}
 
-	return ret_val;
+	return NULL;
 }
 
 void
diff -r 79d6a09303e7 -r cabd145237d8 src/signals.h
--- a/src/signals.h	Thu Apr 07 14:41:18 2005 +0000
+++ b/src/signals.h	Thu Apr 07 14:55:02 2005 +0000
@@ -226,23 +226,29 @@
 void gaim_signal_emit_vargs(void *instance, const char *signal, va_list args);
 
 /**
- * Emits a signal and returns the return value from the last handler.
+ * Emits a signal and returns the first non-NULL return value.
+ *
+ * Further signal handlers are NOT called after a handler returns
+ * something other than NULL.
  *
  * @param instance The instance emitting the signal.
  * @param signal   The signal being emitted.
  *
- * @return The return value from the last handler.
+ * @return The first non-NULL return value
  */
 void *gaim_signal_emit_return_1(void *instance, const char *signal, ...);
 
 /**
- * Emits a signal and returns the return value from the last handler.
+ * Emits a signal and returns the first non-NULL return value.
+ *
+ * Further signal handlers are NOT called after a handler returns
+ * something other than NULL.
  *
  * @param instance The instance emitting the signal.
  * @param signal   The signal being emitted.
  * @param args     The arguments list.
  *
- * @return The return value from the last handler.
+ * @return The first non-NULL return value
  */
 void *gaim_signal_emit_vargs_return_1(void *instance, const char *signal,
 									  va_list args);