gc improvements

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@28234 72102866-910b-0410-8b05-ffd578937521

Source/NSArray.m

@@ -386,6 +386,43 @@ static SEL	rlSel;
   return 0;
 }
 
+- (NSUInteger) countByEnumeratingWithState: (NSFastEnumerationState*)state 	
+				   objects: (id*)stackbuf
+				     count: (NSUInteger)len
+{
+  NSUInteger size = [self count];
+  NSInteger count;
+
+  /* This is cached in the caller at the start and compared at each
+   * iteration.   If it changes during the iteration then
+   * objc_enumerationMutation() will be called, throwing an exception.
+   */
+  state->mutationsPtr = (unsigned long *)size;
+  count = MIN(len, size - state->state);
+  /* If a mutation has occurred then it's possible that we are being asked to
+   * get objects from after the end of the array.  Don't pass negative values
+   * to memcpy.
+   */
+  if (count > 0)
+    {
+      IMP	imp = [self methodForSelector: @selector(objectAtIndex:)];
+      int	p = state->state;
+      int	i;
+
+      for (i = 0; i < count; i++, p++)
+	{
+	  stackbuf[i] = (*imp)(self, @selector(objectAtIndex:), p);
+	}
+      state->state += count;
+    }
+  else
+    {
+      count = 0;
+    }
+  state->itemsPtr = stackbuf;
+  return count;
+}
+
 /**
  * Encodes the receiver for storing to archive or sending over an
  * [NSConnection].