Bug 8832

Summary:	Document that dbus_g_method_get_sender's return needs freeing
Product:	dbus	Reporter:	frederic heem <frederic.heem>
Component:	GLib	Assignee:	Rob Taylor <rob.taylor>
Status:	RESOLVED FIXED	QA Contact:	John (J5) Palmieri <johnp>
Severity:	normal
Priority:	high
Version:	unspecified
Hardware:	Other
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	dbus_g_method_get_sender-return-const-char.txt

Description frederic heem 2006-10-30 06:32:57 UTC

dbus_g_method_get_sender duplicates memory given by dbus_message_get_sender
IMHO, it shouldn't duplicate anything, it should just returns a const gchar* 
returned by dbus_message_get_sender.
This reduced the risk of memory leak  from an application point of view. It is 
also faster.

Comment 1 frederic heem 2006-10-30 06:35:03 UTC

Created attachment 7588 [details] [review]
dbus_g_method_get_sender-return-const-char.txt

Comment 2 Rob Taylor 2006-12-12 05:24:36 UTC

No.

Comment 3 frederic heem 2006-12-12 05:27:11 UTC

Could you please explain why ?

Comment 4 Rob Taylor 2006-12-12 05:29:24 UTC

Because that memory is freed as soon as the message is discarded, it breaks api,
and breaks exitig code.

Comment 5 frederic heem 2006-12-12 05:44:15 UTC

Why dbus-glib imposes the burden of freeing the memory allocated by 
dbus-glib ? 
Anyway, an application must not use the free function of pointer allocated by 
a library. The library shall provide an API to free it itself.
Moreover, the memory is not freed when the message is discarded.

Comment 6 Rob Taylor 2006-12-12 05:54:14 UTC

There is nowhere that dbus-glib could free this sensibly. Its standard glib
practice in such cases that the client code frees the memory (using g_free).
The memory returned by dbus_message_get_sender is a pointer to the string within
the message itself. In the core bindings its fine for dbus_message_get_sender to
return const char* as the user is managing the message lifetime herself, but in
dbus-glib the user should never have to worry about message lifetime (or indeed
messages) so hence the string duplication.

Comment 7 frederic heem 2006-12-12 05:59:13 UTC

Fine, but please document the function that the returned pointer has to be 
freed with g_free.

Comment 8 Rob Taylor 2006-12-12 06:04:53 UTC

Agreed, renamed and reopened bug appropriately

Comment 9 Rob Taylor 2007-02-08 16:02:49 UTC

Fixed in git head.

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