Crash during destruction of shapefile datasources without spatial references

[Kosta]

During the destruction of a OGRShapeLayer object without a valid spatial reference object (poSRS == NULL) a NULL pointer exception is generated when calling "poSRS->Release()".

In OGRFeatureDefn::Release() this case is handled by testing for "this != NULL". The same test should be added to OGRSpatialReference::Release():

Index: ogrspatialreference.cpp
===================================================================
--- ogrspatialreference.cpp	(revision 11280)
+++ ogrspatialreference.cpp	(working copy)
@@ -290,7 +290,7 @@
 void OGRSpatialReference::Release()
 
 {
-    if( Dereference() <= 0 )
+    if( this && Dereference() <= 0 )
         delete this;
 }

[warmerdam]

Mateusz,

I understand you have already re-added the "this" test to the OGRSpatialReference Release method. But it is really an error in calling code to invoke Release on a NULL pointer. So I would like you to:

• Add an assertion in OGRSpatialReference::Release() that this is not NULL.

• Track down the original problem in the shapefile driver so this doesn't occur.

It is sufficient to do this cleanup in trunk.

Thanks...

[Kosta]

But then the same behavior should be implemented for OGRFeatureDefn::Release()!

[Mateusz Łoskot]

Fixed in r11294. Both Frank's and Kosta's suggestions have been applied.

[Kosta]

A related ticket can be found here: #738

[Mateusz Łoskot]

Kosta,

Please, confirm if the fix works for you. Thank you!

[Kosta]

OK, fixed, thx ... :-)