Bug 12966 – REGRESSION(r19952): Crash on page load if user stylesheet enabled.

• Status: RESOLVED
• Resolution: FIXED
• Component: Page Loading

[Mark Rowe (bdash)]

Loading any URL with a user stylesheet enabled results in a null pointer dereference.  Backtrace is below.  DocLoader::requestUserCSSStyleSheet is returning NULL as the URL being loaded is file:// while the document's URL is http://.

This is the exact same crash that occurred in bug 12705 that was fixed in r19524.  The change that introduced that crash was later rolled out, and was landed in a slightly different from in r19952.  The updated change reintroduced the crash.

Exception:  EXC_BAD_ACCESS (0x0001)
Codes:      KERN_PROTECTION_FAILURE (0x0002) at 0x00000000

Thread 0 Crashed:
0   com.apple.WebCore           0x014b011f WebCore::UserStyleSheetLoader::UserStyleSheetLoader[in-charge](WebCore::Frame*, WebCore::String const&, WebCore::DocLoader*) + 119 (Frame.cpp:1
39)
1   com.apple.WebCore           0x010b193d WebCore::Frame::setUserStyleSheetLocation(WebCore::KURL const&) + 269 (Frame.cpp:323)
2   com.apple.WebCore           0x0136f37d WebCore::FrameLoader::begin(WebCore::KURL const&) + 1083 (FrameLoader.cpp:832)
3   com.apple.WebCore           0x0136f481 WebCore::FrameLoader::receivedFirstData() + 39 (FrameLoader.cpp:755)
4   com.apple.WebCore           0x0136f6d7 WebCore::FrameLoader::setEncoding(WebCore::String const&, bool) + 45 (FrameLoader.cpp:1506)
5   com.apple.WebCore           0x010d3d4e -[WebCoreFrameBridge receivedData:textEncodingName:] + 220 (WebCoreFrameBridge.mm:1484)
6   com.apple.WebKit            0x004318f1 -[WebHTMLRepresentation receivedData:withDataSource:] + 199 (WebHTMLRepresentation.mm:175)
7   com.apple.WebKit            0x0042cfa3 -[WebDataSource(WebInternal) _receivedData:] + 89 (WebDataSource.mm:178)
8   com.apple.WebKit            0x004938b5 WebFrameLoaderClient::committedLoad(WebCore::DocumentLoader*, char const*, int) + 127 (WebFrameLoaderClient.mm:644)
9   com.apple.WebCore           0x013662b9 WebCore::FrameLoader::committedLoad(WebCore::DocumentLoader*, char const*, int) + 53 (FrameLoader.cpp:2931)
10  com.apple.WebCore           0x01376969 WebCore::DocumentLoader::commitLoad(char const*, int) + 87 (DocumentLoader.cpp:344)
11  com.apple.WebCore           0x013769c2 WebCore::DocumentLoader::receivedData(char const*, int) + 76 (DocumentLoader.cpp:357)
12  com.apple.WebCore           0x013657c7 WebCore::FrameLoader::receivedData(char const*, int) + 41 (FrameLoader.cpp:1938)
13  com.apple.WebCore           0x013781fe WebCore::MainResourceLoader::addData(char const*, int, bool) + 80 (MainResourceLoader.cpp:133)
14  com.apple.WebCore           0x0137a21f WebCore::ResourceLoader::didReceiveData(char const*, int, long long, bool) + 83
15  com.apple.WebCore           0x01378533 WebCore::MainResourceLoader::didReceiveData(char const*, int, long long, bool) + 281 (MainResourceLoader.cpp:288)
16  com.apple.WebCore           0x01379e86 WebCore::ResourceLoader::didReceiveData(WebCore::ResourceHandle*, char const*, int, int) + 58
17  com.apple.WebCore           0x01359484 -[WebCoreResourceHandleAsDelegate connection:didReceiveData:lengthReceived:] + 172 (ResourceHandleMac.mm:352)
18  com.apple.Foundation        0x92856afa -[NSURLConnection(NSURLConnectionInternal) _sendDidReceiveDataCallback] + 641
19  com.apple.Foundation        0x92854ddb -[NSURLConnection(NSURLConnectionInternal) _sendCallbacks] + 686
20  com.apple.Foundation        0x92854ab5 _sendCallbacks + 201
21  com.apple.CoreFoundation    0x9082df92 CFRunLoopRunSpecific + 1213
22  com.apple.CoreFoundation    0x9082dace CFRunLoopRunInMode + 61

[Mark Rowe (bdash)]

<rdar://problem/5038491>

[Mark Rowe (bdash)]

Kevin landed the fix for this in r19977.