NSGraphicsContext retain cycle

[Alexander Malmberg]

Hi again,

In one of the recent NSApplication updates someone added a comment that
GSCurrentContext() wasn't being dealloc:d properly. A quick search in my
retain/release logs showed me that:

1.
[NSGraphicsContext +graphicsContextWithAttributes:] is only
autoreleasing the new context on one of the branches there.

2.
+setCurrentContext: retains the current context, so the current context
can't be dealloc:d by simply releasing it (although it tries to do a
setCurrentContext: nil in -dealloc). I don't know of any nice way to
patch this (the !GNUSTEP_BASE_LIBRARY case is tricky), so I placed a
setCurrentContext: nil (if self is the current context) in
-destroyContext too.

It seems to work, although I don't know what to make of the comment
above -destroyContext (the context will be dealloc:d right away, not in
the next autoreleasepool).

- Alexander Malmberg

Index: Source/NSGraphicsContext.m
===================================================================
RCS file: /cvsroot/gnustep/gnustep/core/gui/Source/NSGraphicsContext.m,v
retrieving revision 1.50
diff -u -r1.50 NSGraphicsContext.m
--- Source/NSGraphicsContext.m  26 Jan 2002 04:14:38 -0000      1.50
+++ Source/NSGraphicsContext.m  23 Feb 2002 13:39:45 -0000
@@ -153,10 +153,10 @@
               @"Internal Error: No default NSGraphicsContext set\n");
       ctxt = [[defaultNSGraphicsContextClass allocWithZone: _globalGSZone]
               initWithContextInfo: attributes];
-      AUTORELEASE(ctxt);
     }
   else
     ctxt = [[self allocWithZone: _globalGSZone] initWithContextInfo: 
attributes];
+  AUTORELEASE(ctxt);
   return ctxt;
 }
 
@@ -196,6 +196,8 @@
    the next autorelease pool end */
 - (void) destroyContext
 {
+  if (GSCurrentContext()==self)
+    [NSGraphicsContext setCurrentContext: nil];
   [contextLock lock];
   [contextList removeObject: self];
   [contextLock unlock];