Bug 81159 – Assertion failures in WebCore::Page::goBackOrForward causing multiple "crashes" on Lion Intel Debug WebKit2 testers

• Component: History
• Status: RESOLVED FIXED

[Jessie Berlin]

void Page::goBackOrForward(int distance)
{
    if (distance == 0)
        return;

    HistoryItem* item = backForward()->itemAtIndex(distance);
    if (!item) {
        if (distance > 0) {
            if (int forwardCount = backForward()->forwardCount()) 
                item = backForward()->itemAtIndex(forwardCount);
        } else {
            if (int backCount = backForward()->backCount())
                item = backForward()->itemAtIndex(-backCount);
        }
    }

    ASSERT(item);
    if (!item)
        return;

    goToItem(item, FrameLoadTypeIndexedBackForward);
}

It is not clear that the assertion is valid, since it seems possible that you couldn't go back or forward.

This seems separate from the crash with a similar backtrace seen on Lion Intel Debug Tests (http://build.webkit.org/results/Lion%20Intel%20Debug%20%28Tests%29/r110714%20%284462%29/compositing/iframes/page-cache-layer-tree-crash-log.txt)

Unfortunately, I do not know when it started.

Here is a sample:

http://build.webkit.org/results/Lion%20Intel%20Debug%20(WebKit2%20Tests)/r110743%20(4915)/fast/frames/layout-after-destruction-crash-log.txt

Process:         WebProcess [24853]
Path:            /Volumes/VOLUME/*/WebKit2.framework/WebProcess.app/Contents/MacOS/WebProcess
Identifier:      com.apple.WebProcess
Version:         536+ (536.3+)
Code Type:       X86-64 (Native)
Parent Process:  WebKitTestRunner [24842]

Date/Time:       2012-03-14 14:22:29.730 -0700
OS Version:      Mac OS X 10.7.2 (11C74)
Report Version:  9

Crashed Thread:  0  Dispatch queue: com.apple.main-thread

Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x00000000bbadbeef

VM Regions Near 0xbbadbeef:
--> 
    __TEXT                 000000010e447000-000000010e448000 [    4K] r-x/rwx SM=COW  /Volumes/VOLUME/*/WebKit2.framework/WebProcess.app/Contents/MacOS/WebProcess

Application Specific Information:
objc[24853]: garbage collection is OFF

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   com.apple.WebCore             	0x00000001112a1b23 WebCore::Page::goBackOrForward(int) + 291 (Page.cpp:327)
1   com.apple.WebCore             	0x000000011020b3de WebCore::BackForwardController::goBackOrForward(int) + 30 (BackForwardController.cpp:60)
2   com.apple.WebCore             	0x0000000111243b42 WebCore::ScheduledHistoryNavigation::fire(WebCore::Frame*) + 338 (NavigationScheduler.cpp:206)
3   com.apple.WebCore             	0x000000011124181f WebCore::NavigationScheduler::timerFired(WebCore::Timer<WebCore::NavigationScheduler>*) + 175 (NavigationScheduler.cpp:419)
4   com.apple.WebCore             	0x0000000111243893 WebCore::Timer<WebCore::NavigationScheduler>::fired() + 115 (Timer.h:100)
5   com.apple.WebCore             	0x00000001118d0fa7 WebCore::ThreadTimers::sharedTimerFiredInternal() + 311 (ThreadTimers.cpp:118)
6   com.apple.WebCore             	0x00000001118d0ce9 WebCore::ThreadTimers::sharedTimerFired() + 25 (ThreadTimers.cpp:94)
7   com.apple.WebCore             	0x00000001116abcf3 _ZN7WebCoreL10timerFiredEP16__CFRunLoopTimerPv + 67 (SharedTimerMac.mm:167)
8   com.apple.CoreFoundation      	0x00007fff84dcaf84 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
9   com.apple.CoreFoundation      	0x00007fff84dcaad6 __CFRunLoopDoTimer + 534
10  com.apple.CoreFoundation      	0x00007fff84dab471 __CFRunLoopRun + 1617
11  com.apple.CoreFoundation      	0x00007fff84daaae6 CFRunLoopRunSpecific + 230
12  com.apple.HIToolbox           	0x00007fff897253d3 RunCurrentEventLoopInMode + 277
13  com.apple.HIToolbox           	0x00007fff8972c63d ReceiveNextEventCommon + 355
14  com.apple.HIToolbox           	0x00007fff8972c4ca BlockUntilNextEventMatchingListInMode + 62
15  com.apple.AppKit              	0x00007fff8cb3e3f1 _DPSNextEvent + 659
16  com.apple.AppKit              	0x00007fff8cb3dcf5 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 135
17  com.apple.AppKit              	0x00007fff8cb3a62d -[NSApplication run] + 470
18  com.apple.WebCore             	0x00000001115fab4c WebCore::RunLoop::run() + 92 (RunLoopMac.mm:101)
19  com.apple.WebKit2             	0x000000010e912ee4 WebKit::WebProcessMain(WebKit::CommandLine const&) + 3556 (WebProcessMainMac.mm:176)
20  com.apple.WebKit2             	0x000000010e81e76f _ZL10WebKitMainRKN6WebKit11CommandLineE + 239 (WebKitMain.cpp:50)
21  com.apple.WebKit2             	0x000000010e81e652 WebKitMain + 178 (WebKitMain.cpp:74)
22  com.apple.WebProcess          	0x000000010e447d82 main + 290
23  com.apple.WebProcess          	0x000000010e447c54 start + 52

[Radar WebKit Bug Importer]

<rdar://problem/11049870>

[Jessie Berlin]

Fixed in http://trac.webkit.org/changeset/110884