These crashes have been around for a long time, in low numbers. But currently they're the #2 Mac topcrasher on the 41 branch. I suspect they have a very easy fix. https://crash-stats.mozilla.com/search/?signature=RemoveMenuAtIndex&_facets=signature&_columns=date&_columns=signature&_columns=product&_columns=version&_columns=build_id&_columns=platform#facet-signature
These crashes happen here, as we call nsMenuX::NativeMenuItem() on an invalid value referenced by mMenuArray[aIndex]. The invalid values are either NULL or 0x5a5a5a5a5a5a5a5a. https://hg.mozilla.org/mozilla-central/annotate/291614a686f1/widget/cocoa/nsMenuBarX.mm#l249 At first I thought we might be adding invalid values to mMenuArray in nsMenuBarX::InsertMenuAtIndex(). But we only have two calls to this method, and both insert a new nsMenuX object immediately after creating it, so I think this is impossible. https://hg.mozilla.org/mozilla-central/annotate/291614a686f1/widget/cocoa/nsMenuBarX.mm#l140 https://hg.mozilla.org/mozilla-central/annotate/291614a686f1/widget/cocoa/nsMenuBarX.mm#l280 So looking at the top of nsMenuBarX::InsertMenuAtIndex(), it's pretty clear what the problem is: We only check that aIndex < mMenuArray.Length() in debug builds (we only do an assertion). Instead we should always return early, and call NS_ERROR. Patch coming up shortly.
Here's my patch. I've started a set of tryserver builds: https://treeherder.mozilla.org/#/jobs?repo=try&revision=0b951427650d
Assignee: nobody → smichaud
Status: NEW → ASSIGNED
Attachment #8627938 - Flags: review?(spohl.mozilla.bugs)
Attachment #8627938 - Flags: review?(spohl.mozilla.bugs) → review+
Comment on attachment 8627938 [details] [diff] [review] Fix Approval Request Comment [Feature/regressing bug #]: Old bug [User impact if declined]: Crashes, at high volume on aurora (41 branch) [Describe test coverage new/current, TreeHerder]: Baked for several days on mozilla-central [Risks and why]: Low risk -- patch just changes an assertion to an early return [String/UUID change made/needed]: None These crashes have disappeared from the firefox-2015-07-03-03-03-44-mozilla-central and later nightlies. So I'm going to mark this bug VERIFIED. I'll also request upload to aurora and beta. These aren't a topcrasher on the 40 branch (beta). But the patch is very simple and low risk, and we're quite early in the beta cycle.
Comment on attachment 8627938 [details] [diff] [review] Fix Verified crash fix. Given that the fix has been verified and that it is early in Beta, we'll take this in Beta as well as Aurora. Aurora+ Beta+
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