Since inputStream is nullptr, this crash occurs. we need consider that inputStream (2nd param) is nullptr. bp-9c240ff2-9223-4f03-a1b9-fb7f72120813 0 xul.dll nsNNTPProtocol::ProcessProtocolState mailnews/news/src/nsNNTPProtocol.cpp:4411 1 xul.dll nsNNTPProtocol::OnPromptCanceled mailnews/news/src/nsNNTPProtocol.cpp:2592 2 xul.dll nsNNTPProtocol::OnPromptStart mailnews/news/src/nsNNTPProtocol.cpp:2564 3 xul.dll NS_InvokeByIndex_P xpcom/reflect/xptcall/src/md/win32/xptcinvoke.cpp:102 4 xul.dll XPCWrappedNative::CallMethod js/xpconnect/src/XPCWrappedNative.cpp:2409 5 xul.dll XPC_WN_CallMethod js/xpconnect/src/XPCWrappedNativeJSOps.cpp:1554 6 mozjs.dll js::InvokeKernel js/src/jsinterp.cpp:519 7 mozjs.dll js::Interpret js/src/jsinterp.cpp:2757 8 mozjs.dll JSScript::makeAnalysis js/src/jsinfer.cpp:5372 9 mozjs.dll js::RunScript js/src/jsinterp.cpp:475 10 mozjs.dll js::InvokeKernel js/src/jsinterp.cpp:535 11 mozjs.dll js::Invoke js/src/jsinterp.cpp:567 12 mozjs.dll JS_CallFunctionValue js/src/jsapi.cpp:5429 13 xul.dll nsXPCWrappedJSClass::CallMethod js/xpconnect/src/XPCWrappedJSClass.cpp:1509 14 xul.dll nsXPCWrappedJS::CallMethod js/xpconnect/src/XPCWrappedJS.cpp:617 15 xul.dll PrepareAndDispatch xpcom/reflect/xptcall/src/md/win32/xptcstubs.cpp:117 16 xul.dll SharedStub xpcom/reflect/xptcall/src/md/win32/xptcstubs.cpp:144 17 xul.dll nsThread::ProcessNextEvent xpcom/threads/nsThread.cpp:656

A patch.

So why wouldn't we want to pass mInputStream?

mInputStream is only used in the case where we're being called from the timer callback in the LIST case, so it's only set in ReadNewsList.

Comment on attachment 652975 [details] [diff] [review] Null-check the inputStream Fair enough.

This is a low-level crash in TB14, Joshua, should we advance this forward to 16, to push out the fix earlier?

I see no problems doing so.

Comment on attachment 652975 [details] [diff] [review] Null-check the inputStream [Triage Comment] This is already on aurora, but taking forward to beta/16 as per previous comments.

Checked in: https://hg.mozilla.org/releases/comm-beta/rev/c574e4e79baf