Attaching a test case which reveals that WebKit normalizes path segments (all straight segments become PATHSEG_LINETO_ABS). It's my understanding based on http://www.w3.org/TR/SVG11/paths.html#InterfaceSVGAnimatedPathData that only normalizedPathSegList should have normalized segments and that pathSegList should contain the segments as they were written.
Created attachment 31427 [details]
Test case revealing the problem.
Mozilla and Opera both pass this test.
*** Bug 25968 has been marked as a duplicate of this bug. ***
*** Bug 30222 has been marked as a duplicate of this bug. ***
Fixing this bug would make bug 30219 much easier to fix properly as well.
The test case works correctly in Safari 5.1.3. I don't know when differentiated path segment types were added to the pathSegList, but they are there now (and have been for some time). I believe that this bug is fixed and should be closed.