<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW --- - Segmentation fault when using a complex path for clip and stroke" href="https://bugs.freedesktop.org/show_bug.cgi?id=74779#c8">Comment # 8</a> on <a class="bz_bug_link bz_status_NEW " title="NEW --- - Segmentation fault when using a complex path for clip and stroke" href="https://bugs.freedesktop.org/show_bug.cgi?id=74779">bug 74779</a> from <a class="email" href="mailto:sixtysix@inwind.it" title="Massimo <sixtysix@inwind.it>"> Massimo</a> <pre>Re the problem caused by using the difference between ptrs: initially I thought that the problem was that the difference between raw pointers to stack/heap allocated objects could exceed 2^31 * sizeof(cairo_bo_event_t) and so not representable as an int. But reading better the code the problem is that you're computing the difference between addresses of objects of different types (cairo_bo_start_event_t and cairo_bo_queue_event_t) using pointers to another type (cairo_bo_event_t). When the raw difference is not divisible by 'sizeof(cairo_bo_event_t)' the result is random. In C, technically, relational operations between pointers are defined only for pointers to objects from the same array etc. (in C++ it is possible to use std::less that hides the magic necessary to make it well defined). To be on the safe side you'd better cast the pointers to uintptr_t and return -1 or 0 or 1 for <, ==, >.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>