I set the following prefs and restarted the browser: logging.nsHttp = 5 logging.nsHostResolver = 5 logging.nsSocketTransport = 5 logging.nsStreamPump = 5 no env variables are set - logging is done at stderr When opening a new tab, to say google.com, it crashes. I can reproduce it almost immediately.

Confirmed, I was able to repro on linux w/ the specified prefs and navigating to youtube.com. It appears that the va_list is getting trashed when going into the long logline path.

Comment on attachment 8708223 [details] [diff] [review] Copy va_list before using it in LogModuleManager::Print Review of attachment 8708223 [details] [diff] [review]: ----------------------------------------------------------------- Ah, whoops!

https://hg.mozilla.org/integration/mozilla-inbound/rev/1e81d89a1c98c233989d675ce85b07c2b4887d3a Bug 1239941 - Copy va_list before using it in LogModuleManager::Print. r=froydnj

Does that mean we need va_copy whenever passing a va_list to another function like: void foo(va_list va) { va_list va1; va_copy(va1, va); bar1(va1); va_end(va1); } void bar1(va_list va1) { va_list va2; va_copy(va2, va1); bar2(va2); va_end(va2); } void bar2(va_list va2) { va_list va3; va_copy(va3, va2); bar3(va3); va_end(va3); }

(In reply to JW Wang [:jwwang] from comment #6) > Does that mean we need va_copy whenever passing a va_list to another > function like: > > void foo(va_list va) { > va_list va1; > va_copy(va1, va); > bar1(va1); > va_end(va1); > } > > void bar1(va_list va1) { > va_list va2; > va_copy(va2, va1); > bar2(va2); > va_end(va2); > } > > void bar2(va_list va2) { > va_list va3; > va_copy(va3, va2); > bar3(va3); > va_end(va3); > } Only if it's used more than once. I don't think that would necessarily hurt anything though. In this case we sometimes used it twice, ie: > void foo(va_list va) { > if (!bar(va)) > bar2(va); > } And the fix was to copy it for the first case: > void foo(va_list va) { > va_list va1; va_copy(va1, va); > if (!bar(va)) > bar2(va); > va_end(va1); > }