While investigating a plethora of upstream kde/okular crash reports, lately, I came upon the fact that poppler built with poppler-ObjStream.patch, when used with evn var MALLOC_CHECK_=2 (or equivalent, which happens to be enabled by default during kde beta phases), poppler-based pdf viewers will segfault quite easily (usually scrolling). I tested with both okular and evince, same badness going on. This patch seems to go back quite a ways, but I can't determine really why we're still carrying it. (and why not upstreamed?) Based on the answer(s) to that, we can find ways to remove or fix/upstream this.
Looks like it is indeed needed for texlive/pdftex, now documenting as such in the .spec. I seem to be able to get crashers now using MALLOC_CHECK!=0, with or without the patch, so blame is likely elsewhere.
*** Bug 560991 has been marked as a duplicate of this bug. ***