Fix for circular references detection in almost all cases, fixing https://bugs.launchpad.net/inkscape/+bug/167247 and a few of its duplicates.

This fix is aimed at preventing any sort of circular references with the URIReference::_acceptObject method, checking the absence of loops in the reference+child tree.

There can be some performance improvements done if we add a pointer from cloned sub-objects to their origin sub-object. 

The remaining cases that are not fixed can involve non-trivial loops using one or more "url()" stylesheet references. Being able to take them into account would require a non-obvious style.cpp refactoring making use of URIReference for this kind of reference (and not handling manually the signals in the styling code, which would probably be a good thing to do anyway)

(bzr r14245)

1 files changed, 2 insertions, 1 deletions

diff --git a/src/persp3d-reference.cpp b/src/persp3d-reference.cpp
index 895eac6f2..4526a8d8f 100644
--- a/src/persp3d-reference.cpp
+++ b/src/persp3d-reference.cpp
@@ -35,7 +35,8 @@ Persp3DReference::~Persp3DReference(void)
 bool
 Persp3DReference::_acceptObject(SPObject *obj) const
 {
-    return SP_IS_PERSP3D(obj);
+    return SP_IS_PERSP3D(obj) && URIReference::_acceptObject(obj);
+;
     /* effic: Don't bother making this an inline function: _acceptObject is a virtual function,
        typically called from a context where the runtime type is not known at compile time. */
 }