Bug 199327 - Null check provisionalItem in FrameLoader::continueLoadAfterNavigationPolicy
Summary: Null check provisionalItem in FrameLoader::continueLoadAfterNavigationPolicy
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: New Bugs (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Alex Christensen
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2019-06-28 11:09 PDT by Alex Christensen
Modified: 2019-07-01 14:11 PDT (History)
8 users (show)

See Also:


Attachments
Patch (1.85 KB, patch)
2019-06-28 11:10 PDT, Alex Christensen
no flags Details | Formatted Diff | Diff

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Description Alex Christensen 2019-06-28 11:09:10 PDT
Null check provisionalItem in FrameLoader::continueLoadAfterNavigationPolicy
Comment 1 Alex Christensen 2019-06-28 11:10:06 PDT
Created attachment 373135 [details]
Patch
Comment 2 Alex Christensen 2019-06-28 11:10:08 PDT
<rdar://problem/48262384>
Comment 3 Daniel Bates 2019-06-28 23:16:49 PDT
Comment on attachment 373135 [details]
Patch

So, I’ve been out of this code for a while. But I spent like ***20**** seconds just grepping this file for provisionalItem and I can say that this patch makes absolutely no sense to me. Hint: It contradicts a bunch of RELEASE_ASSERTS. And with 0 details about why this fix is necessary except an appeal to “Let’s not crash” I have no means of helping you further (I don’t have a radar client handy at the moment).
Comment 4 Maciej Stachowiak 2019-07-01 02:23:21 PDT
This is an attempt to fix a top crash based on telemetry. It doesn't contradict a RELEASE_ASSERT in the control flow path that led to the crash, because otherwise these crashes would have crashed earlier. The crash is known to be a null Derek on this line. So this is probably sensible as a speculative fix, even though there's probably something deeper wrong here.
Comment 5 Ryosuke Niwa 2019-07-01 13:17:43 PDT
(In reply to Daniel Bates from comment #3)
> Comment on attachment 373135 [details]
> Patch
> 
> So, I’ve been out of this code for a while. But I spent like ***20****
> seconds just grepping this file for provisionalItem and I can say that this
> patch makes absolutely no sense to me. Hint: It contradicts a bunch of
> RELEASE_ASSERTS. And with 0 details about why this fix is necessary except
> an appeal to “Let’s not crash” I have no means of helping you further (I
> don’t have a radar client handy at the moment).

That is true but we've been trying to fix this particular crash for the last 2-3 releases and at some point, we need to fix the damn crash for the sake of our users instead of keep investigating what the root cause is.
Comment 6 WebKit Commit Bot 2019-07-01 14:11:47 PDT
Comment on attachment 373135 [details]
Patch

Clearing flags on attachment: 373135

Committed r247021: <https://trac.webkit.org/changeset/247021>
Comment 7 WebKit Commit Bot 2019-07-01 14:11:48 PDT
All reviewed patches have been landed.  Closing bug.