Merge pull request #6168 from johnhaddon/catalogueDragFix

CatalogueUI : Don't "steal" irrelevant drags

Changes.md

@@ -6,6 +6,7 @@ Fixes
 
 - GraphEditor : Fixed errors when dragging an unknown file type into the GraphEditor.
 - Widget : Fixed `event.sourceWidget` for DragDropEvents generated from a Qt native drag within the same Gaffer process. This will now reference the `GafferUI.Widget` that the Qt source widget belongs to, if any.
+- Catalogue : Fixed bug which "stole" drags that crossed the image listing but which were destined elsewhere, for instance a drag from the HierarchyView to a PathFilter in the GraphEditor.
 
 1.4.15.2 (relative to 1.4.15.1)
 ========

python/GafferImageUI/CatalogueUI.py

@@ -1079,7 +1079,7 @@ def __dropImage( self, eventData ) :
 
 	def __pathListingDragEnter( self, widget, event ) :
 
-		if isinstance( event.data, IECore.StringVectorData ) :
+		if event.sourceWidget is widget and isinstance( event.data, IECore.StringVectorData ) and event.data :
 			# Allow reordering of images
 			self.__moveToPath = None
 			self.__mergeGroupId += 1
@@ -1101,7 +1101,7 @@ def __pathListingDragLeave( self, widget, event ) :
 
 	def __pathListingDragMove( self, listing, event ) :
 
-		if not event.data or not isinstance( event.data, IECore.StringVectorData ) :
+		if not ( event.sourceWidget is listing and isinstance( event.data, IECore.StringVectorData ) and event.data ) :
 			return
 
 		targetPath = self.__pathListing.pathAt( event.line.p0 )