Created attachment 8675229 [details] Backtrace STR: - Prefs>Advanced>Network, set a random nonexistant HTTP proxy (ensure that you set a port). - Open websites. Firefox will crash. Top of backtrace (full bt attached): #0 0x00007fffe8af9bfc in fetch_sub (__m=std::memory_order_seq_cst, __i=1, this=this@entry=0x8) at /usr/include/c++/4.9/bits/atomic_base.h:628 #1 sub (aVal=1, aPtr=...) at ../../dist/include/mozilla/Atomics.h:259 #2 dec (aPtr=...) at ../../dist/include/mozilla/Atomics.h:291 #3 mozilla::detail::AtomicBaseIncDec<unsigned long, (mozilla::MemoryOrdering)2>::operator-- (this=this@entry=0x8) at ../../dist/include/mozilla/Atomics.h:565 #4 0x00007fffe8b88710 in operator-- (this=0x8) at ../../dist/include/nsISupportsImpl.h:353 #5 nsProxyInfo::Release (this=0x0) at /home/manishearth/Mozilla/mozilla-central/netwerk/base/nsProxyInfo.cpp:11 #6 0x00007fffe8b88983 in nsProtocolProxyService::PruneProxyInfo (this=0x7fffdb71f600, info=..., list=0x7fffffff99d0) at /home/manishearth/Mozilla/mozilla-central/netwerk/base/nsProtocolProxyService.cpp:2011 #7 0x00007fffe8b88b5e in nsProtocolProxyService::ApplyFilters (this=0x7fffdb71f600, channel=0x7fffccdffa50, info=..., list=0x7fffffff99d0) at /home/manishearth/Mozilla/mozilla-central/netwerk/base/nsProtocolProxyService.cpp:1930 #8 0x00007fffe8b8ebe0 in nsProtocolProxyService::ApplyFilters (this=<optimized out>, channel=<optimized out>, info=..., proxyInfo=...) at /home/manishearth/Mozilla/mozilla-central/netwerk/base/nsProtocolProxyService.h:253 #9 0x00007fffe8b8bdf5 in nsProtocolProxyService::AsyncResolveInternal (this=0x7fffdb71f600, channel=0x7fffccdffa50, flags=0, callback=0x7fffffff9a30, result=0x7fffccdffed0, isSyncOK=5) at /home/manishearth/Mozilla/mozilla-central/netwerk/base/nsProtocolProxyService.cpp:1273 I had been editing nsProtocolProxyService.cpp, but I did an hg qpop, and a clean (not even clobber, deleted the objdir) build of nightly and it still happens.
This happens on the downloadable nightly too. I'm on linux.
The nightly was from 20151016030228 https://hg.mozilla.org/mozilla-central/rev/d374d16cbb251c9dac5af69f8e186e821ce82fe2
:capella verified that the same thing crashes on his machine too (nightly build). Bogus proxy needs to be something like `foo.bar`, just setting a random IP address won't work. 20151013030225 https://hg.mozilla.org/mozilla-central/rev/607a236c229994df99766c005f9ec729532d7747 is another crashing nightly 20150929102827 https://hg.mozilla.org/mozilla-central/rev/ccee6614fd9d18a31f263fbcfe9676b224d851aa isn't. I'm going to bisect.
http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2015-10-12-03-06-12-mozilla-central/firefox-44.0a1.en-US.linux-x86_64.tar.bz2 20151012030612 https://hg.mozilla.org/mozilla-central/rev/0b69d304f861d0038fb78f1d52b0f5d13ef7c6fe is the earliest crashing nightly. This seems to have been caused by bug 1121800.