Bug 12947 – REGRESSION: ASSERTION FAILED: maxWidth >= 0 in StringTruncator.cpp:109 in WebCore::truncateString()

• Component: New Bugs
• Status: RESOLVED FIXED

[David Kilzer (:ddkilzer)]

Summary:

Opening a page in a background tab (via command-clicking) that opens a pop-under window causes an assertion failure in a debug build of WebKit.

Steps to reproduce:

1. Open Safari/WebKit.
2. Make sure the "popunder" cookie for network-drivers.com is NOT set via Safari preferences.
3. Make sure "Block Pop-Up Windows" is NOT set.
4. Command-click on URL:  http://www.network-drivers.com/drivers/53/53064.htm

Expected results:

The page should open without an assertion failure.

Actual results:

The page causes an assertion failure and Safari/WebKit crashes on a debug build.

Regression:

Not tested for regression with Safari 2.0.4 yet.

Notes:

Console output from assertion failure:

ASSERTION FAILED: maxWidth >= 0
(/Users/dkilzer/Projects/WebKit/WebCore/platform/StringTruncator.cpp:109 WebCore::String WebCore::truncateString(const WebCore::String&, float, const WebCore::Font&, unsigned int (*)(const WebCore::String&, unsigned int, unsigned int, UChar*)))
Segmentation fault

Stack trace:

Exception:  EXC_BAD_ACCESS (0x0001)
Codes:      KERN_INVALID_ADDRESS (0x0001) at 0xbbadbeef

Thread 0 Crashed:
0   com.apple.WebCore        	0x013c7cbc WebCore::truncateString(WebCore::String const&, float, WebCore::Font const&, unsigned (*)(WebCore::String const&, unsigned, unsigned, unsigned short*)) + 124
1   com.apple.WebCore        	0x013c81c9 WebCore::StringTruncator::centerTruncate(WebCore::String const&, float, WebCore::Font const&) + 57
2   com.apple.WebKit         	0x00311149 +[WebStringTruncator centerTruncateString:toWidth:withFont:] + 67 (WebStringTruncator.m:74)
3   com.apple.Safari         	0x000108f3 0x1000 + 63731
4   com.apple.AppKit         	0x93375246 -[NSView resizeWithOldSuperviewSize:] + 451
5   com.apple.AppKit         	0x932b7f45 -[NSView resizeSubviewsWithOldSize:] + 168
6   com.apple.AppKit         	0x93296b4d -[NSView setFrameSize:] + 288
7   com.apple.AppKit         	0x93374996 -[NSThemeFrame setFrameSize:] + 421
8   com.apple.AppKit         	0x932f5d41 -[NSWindow _oldPlaceWindow:] + 1414
9   com.apple.AppKit         	0x932f54bb -[NSWindow _setFrameCommon:display:stashSize:] + 418
10  com.apple.AppKit         	0x932fa0ea -[NSWindow setFrame:display:] + 77
11  com.apple.Safari         	0x000107f3 0x1000 + 63475
12  com.apple.Safari         	0x00093cc1 0x1000 + 601281
13  com.apple.Safari         	0x00093d7c 0x1000 + 601468
14  com.apple.Safari         	0x000a87da 0x1000 + 686042
15  libobjc.A.dylib          	0x90a59d76 objc_msgSendv + 54
16  com.apple.Foundation     	0x925ff43e -[NSInvocation invoke] + 932
17  com.apple.Foundation     	0x92625433 -[NSInvocation invokeWithTarget:] + 67
18  com.apple.WebKit         	0x0035f58a -[_WebSafeForwarder forwardInvocation:] + 448 (WebView.mm:1452)
19  com.apple.Foundation     	0x925fe4f4 -[NSObject(NSForwardInvocation) forward::] + 469
20  libobjc.A.dylib          	0x90a59cc1 _objc_msgForward + 49
21  com.apple.WebKit         	0x00397312 WebChromeClient::setWindowRect(WebCore::FloatRect const&) + 202 (WebChromeClient.mm:73)
22  com.apple.WebCore        	0x013836b5 WebCore::Chrome::setWindowRect(WebCore::FloatRect const&) const + 37 (Chrome.cpp:51)
23  com.apple.WebCore        	0x01373fe2 WebCore::FrameLoader::createWindow(WebCore::FrameLoadRequest const&, WebCore::WindowFeatures const&) + 1410 (FrameLoader.cpp:300)
24  com.apple.WebCore        	0x012470c0 KJS::WindowFunc::callAsFunction(KJS::ExecState*, KJS::JSObject*, KJS::List const&) + 4006 (kjs_window.cpp:1651)
25  com.apple.JavaScriptCore 	0x004fc038 KJS::JSObject::call(KJS::ExecState*, KJS::JSObject*, KJS::List const&) + 210 (object.cpp:97)
26  com.apple.JavaScriptCore 	0x004f1ebf KJS::FunctionCallDotNode::evaluate(KJS::ExecState*) + 843 (nodes.cpp:780)
27  com.apple.JavaScriptCore 	0x004f5779 KJS::AssignResolveNode::evaluate(KJS::ExecState*) + 313 (nodes.cpp:1428)
28  com.apple.JavaScriptCore 	0x004ef0dc KJS::ExprStatementNode::execute(KJS::ExecState*) + 148 (nodes.cpp:1680)
29  com.apple.JavaScriptCore 	0x004eccd4 KJS::SourceElementsNode::execute(KJS::ExecState*) + 256 (nodes.cpp:2457)
30  com.apple.JavaScriptCore 	0x004eb60c KJS::BlockNode::execute(KJS::ExecState*) + 140 (nodes.cpp:1656)
31  com.apple.JavaScriptCore 	0x004dde96 KJS::DeclaredFunctionImp::execute(KJS::ExecState*) + 50 (function.cpp:362)
32  com.apple.JavaScriptCore 	0x004e0179 KJS::FunctionImp::callAsFunction(KJS::ExecState*, KJS::JSObject*, KJS::List const&) + 573 (function.cpp:111)
33  com.apple.JavaScriptCore 	0x004fc038 KJS::JSObject::call(KJS::ExecState*, KJS::JSObject*, KJS::List const&) + 210 (object.cpp:97)
34  com.apple.JavaScriptCore 	0x004f2640 KJS::FunctionCallResolveNode::evaluate(KJS::ExecState*) + 716 (nodes.cpp:687)
35  com.apple.JavaScriptCore 	0x004ef0dc KJS::ExprStatementNode::execute(KJS::ExecState*) + 148 (nodes.cpp:1680)
36  com.apple.JavaScriptCore 	0x004eccd4 KJS::SourceElementsNode::execute(KJS::ExecState*) + 256 (nodes.cpp:2457)
37  com.apple.JavaScriptCore 	0x004eb60c KJS::BlockNode::execute(KJS::ExecState*) + 140 (nodes.cpp:1656)
38  com.apple.JavaScriptCore 	0x004eefd0 KJS::IfNode::execute(KJS::ExecState*) + 420 (nodes.cpp:1699)
39  com.apple.JavaScriptCore 	0x004eccd4 KJS::SourceElementsNode::execute(KJS::ExecState*) + 256 (nodes.cpp:2457)
40  com.apple.JavaScriptCore 	0x004eb60c KJS::BlockNode::execute(KJS::ExecState*) + 140 (nodes.cpp:1656)
41  com.apple.JavaScriptCore 	0x004dde96 KJS::DeclaredFunctionImp::execute(KJS::ExecState*) + 50 (function.cpp:362)
42  com.apple.JavaScriptCore 	0x004e0179 KJS::FunctionImp::callAsFunction(KJS::ExecState*, KJS::JSObject*, KJS::List const&) + 573 (function.cpp:111)
43  com.apple.JavaScriptCore 	0x004fc038 KJS::JSObject::call(KJS::ExecState*, KJS::JSObject*, KJS::List const&) + 210 (object.cpp:97)
44  com.apple.JavaScriptCore 	0x004f2640 KJS::FunctionCallResolveNode::evaluate(KJS::ExecState*) + 716 (nodes.cpp:687)
45  com.apple.JavaScriptCore 	0x004ef0dc KJS::ExprStatementNode::execute(KJS::ExecState*) + 148 (nodes.cpp:1680)
46  com.apple.JavaScriptCore 	0x004ef037 KJS::IfNode::execute(KJS::ExecState*) + 523 (nodes.cpp:1706)
47  com.apple.JavaScriptCore 	0x004ece0a KJS::SourceElementsNode::execute(KJS::ExecState*) + 566 (nodes.cpp:2463)
48  com.apple.JavaScriptCore 	0x004eb60c KJS::BlockNode::execute(KJS::ExecState*) + 140 (nodes.cpp:1656)
49  com.apple.JavaScriptCore 	0x004e5a45 KJS::Interpreter::evaluate(KJS::UString const&, int, KJS::UChar const*, int, KJS::JSValue*) + 977 (interpreter.cpp:369)
50  com.apple.WebCore        	0x0123c159 WebCore::KJSProxy::evaluate(WebCore::String const&, int, WebCore::String const&, WebCore::Node*) + 319 (kjs_proxy.cpp:74)
51  com.apple.WebCore        	0x01373453 WebCore::FrameLoader::executeScript(WebCore::String const&, int, WebCore::Node*, WebCore::String const&) + 99 (FrameLoader.cpp:681)
52  com.apple.WebCore        	0x0101ddaa WebCore::HTMLTokenizer::scriptExecution(WebCore::DeprecatedString const&, WebCore::HTMLTokenizer::State, WebCore::DeprecatedString, int) + 316 (HTMLTokenizer.cpp:502)
53  com.apple.WebCore        	0x01020565 WebCore::HTMLTokenizer::scriptHandler(WebCore::HTMLTokenizer::State) + 1449 (HTMLTokenizer.cpp:452)
54  com.apple.WebCore        	0x01020a5e WebCore::HTMLTokenizer::parseSpecial(WebCore::SegmentedString&, WebCore::HTMLTokenizer::State) + 918 (HTMLTokenizer.cpp:310)
55  com.apple.WebCore        	0x010223fd WebCore::HTMLTokenizer::parseTag(WebCore::SegmentedString&, WebCore::HTMLTokenizer::State) + 5255 (HTMLTokenizer.cpp:1175)
56  com.apple.WebCore        	0x01022bc1 WebCore::HTMLTokenizer::write(WebCore::SegmentedString const&, bool) + 1173 (HTMLTokenizer.cpp:1389)
57  com.apple.WebCore        	0x01368ae9 WebCore::FrameLoader::write(char const*, int, bool) + 923 (FrameLoader.cpp:878)
58  com.apple.WebCore        	0x01368c1b WebCore::FrameLoader::addData(char const*, int) + 275 (FrameLoader.cpp:1492)
59  com.apple.WebCore        	0x010cfd6d -[WebCoreFrameBridge addData:] + 163 (WebCoreFrameBridge.mm:294)
60  com.apple.WebCore        	0x010d30f8 -[WebCoreFrameBridge receivedData:textEncodingName:] + 250 (WebCoreFrameBridge.mm:1484)
61  com.apple.WebKit         	0x00331c19 -[WebHTMLRepresentation receivedData:withDataSource:] + 199 (WebHTMLRepresentation.mm:175)
62  com.apple.WebKit         	0x0032d2cb -[WebDataSource(WebInternal) _receivedData:] + 89 (WebDataSource.mm:178)
63  com.apple.WebKit         	0x00393bb9 WebFrameLoaderClient::committedLoad(WebCore::DocumentLoader*, char const*, int) + 127 (WebFrameLoaderClient.mm:644)
64  com.apple.WebCore        	0x01365515 WebCore::FrameLoader::committedLoad(WebCore::DocumentLoader*, char const*, int) + 53 (FrameLoader.cpp:2877)
65  com.apple.WebCore        	0x013759c7 WebCore::DocumentLoader::commitLoad(char const*, int) + 87 (DocumentLoader.cpp:339)
66  com.apple.WebCore        	0x01375a20 WebCore::DocumentLoader::receivedData(char const*, int) + 76 (DocumentLoader.cpp:352)
67  com.apple.WebCore        	0x01364a23 WebCore::FrameLoader::receivedData(char const*, int) + 41 (FrameLoader.cpp:1884)
68  com.apple.WebCore        	0x0137725e WebCore::MainResourceLoader::addData(char const*, int, bool) + 80 (MainResourceLoader.cpp:133)
69  com.apple.WebCore        	0x013792ab WebCore::ResourceLoader::didReceiveData(char const*, int, long long, bool) + 83
70  com.apple.WebCore        	0x01377593 WebCore::MainResourceLoader::didReceiveData(char const*, int, long long, bool) + 281 (MainResourceLoader.cpp:290)
71  com.apple.WebCore        	0x01378f12 WebCore::ResourceLoader::didReceiveData(WebCore::ResourceHandle*, char const*, int, int) + 58
72  com.apple.WebCore        	0x01358768 -[WebCoreResourceHandleAsDelegate connection:didReceiveData:lengthReceived:] + 172 (ResourceHandleMac.mm:352)
73  com.apple.Foundation     	0x9265eb86 -[NSURLConnection(NSURLConnectionInternal) _sendDidReceiveDataCallback] + 641
74  com.apple.Foundation     	0x9265ce67 -[NSURLConnection(NSURLConnectionInternal) _sendCallbacks] + 686
75  com.apple.Foundation     	0x9265cb41 _sendCallbacks + 201
76  com.apple.CoreFoundation 	0x9082afd2 CFRunLoopRunSpecific + 1213
77  com.apple.CoreFoundation 	0x9082ab0e CFRunLoopRunInMode + 61
78  com.apple.HIToolbox      	0x92ddabef RunCurrentEventLoopInMode + 285
79  com.apple.HIToolbox      	0x92dda2fd ReceiveNextEventCommon + 385
80  com.apple.HIToolbox      	0x92dda154 BlockUntilNextEventMatchingListInMode + 81
81  com.apple.AppKit         	0x9327f465 _DPSNextEvent + 572
82  com.apple.AppKit         	0x9327f056 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 137
83  com.apple.Safari         	0x00006cea 0x1000 + 23786
84  com.apple.AppKit         	0x93278ddb -[NSApplication run] + 512
85  com.apple.AppKit         	0x9326cd2f NSApplicationMain + 573
86  com.apple.Safari         	0x0005f54a 0x1000 + 386378
87  com.apple.Safari         	0x0005f471 0x1000 + 386161

[David Kilzer (:ddkilzer)]

This is a regression from shipping Safari 2.0.4 (419.3) on Mac OS X 10.4.8 (8N1037).

Tested with a local debug build of WebKit r19943 with the above software.

[Alexey Proskuryakov]

I cannot reproduce this on a PowerPC Mac.

[David Kilzer (:ddkilzer)]

(In reply to comment #2)
> I cannot reproduce this on a PowerPC Mac.

Weird!  I can't reproduce this with my PB G4, either.  Local debug build of WebKit r19943 with Safari 2.0.4 (419.3) on Mac OS X 10.4.8 (8L127).

[David Kilzer (:ddkilzer)]

(In reply to comment #2)
> I cannot reproduce this on a PowerPC Mac.

The issue is most likely caused by differences in how NaN floating point values are handled on PowerPC versus Intel architectures.  Obviously, this code from StringTruncator.cpp (line 109) returns true with a NaN on PowerPC, but false with a NaN on Intel:

     ASSERT(maxWidth >= 0);

I added an additional ASSERT() macro to the Intel debug build:

+    ASSERT(!isnan(maxWidth));
     ASSERT(maxWidth >= 0);

And rerunning the steps to reproduce demonstrated that maxWidth was a NaN value:

ASSERTION FAILED: !isnan(maxWidth)
(/Users/dkilzer/Projects/WebKit/WebCore/platform/StringTruncator.cpp:109 WebCore::String WebCore::truncateString(const WebCore::String&, float, const WebCore::Font&, unsigned int (*)(const WebCore::String&, unsigned int, unsigned int, UChar*)))
Segmentation fault

Not sure if we need to determine where the NaN is generated, or simply handle the NaN case differently in the truncateString(const String& string, float maxWidth, const Font& font, TruncationFunction truncateToBuffer) method.

[Jeff McGlynn]

This bug is hard to reproduce.  The steps that I take to reliably test the bug are:

1. Open Webkit
2. Make sure the "popunder" cookie for network-drivers.com is NOT set via Safari preferences.
3. Set "Accept Cookies" to Never.
3. Make sure "Block Pop-Up Windows" is NOT set.
4. Command-click on URL:  http://www.network-drivers.com/drivers/53/53064.htm
5. Repeat step 4 until you see detailed popup that contains bar graphs.

So far I have isolated the bug to between WebKit-SVN-r17653.dmg (works) and WebKit-SVN-r17656.dmg (crashes).

I have an iMac G5 and 10.4.8.

[Jeff McGlynn]

Created attachment 13457 [details]
Reduction

Command-click to open this attachment to crash Webkit.

I believe that this bug is a GC-related error.  The original page can be fixed by removing the "left=85,top=20," from the popup parameters.

Accessing the zero index of an array and either a left= or top= parameter are necessary for this crash.

[Mark Rowe (bdash)]

The root of this problem is that kjs_window.cpp:1616 calls WebCore::screenRect with null as the argument.  This results in toUserSpace invoking Objective-C methods on nil objects, which will either return zero or an undefined value depending on the return type of the method in question.  This looks to cause userRect to be scaled by NaN, eventually leading to the assertion failure mentioned in this bug report.

One strange thing I noticed while debugging this is that the x/y/width/height members of the WindowFeatures structure are not initialized, and in many cases are used before initialization.  This could lead in some cases for windows created via window.open to have arbitrary sizes and locations while still being constrained within the screens bounds.

[Mark Rowe (bdash)]

Created attachment 13477 [details]
Patch

[Mark Rowe (bdash)]

Comment on attachment 13477 [details]
Patch

I didn't include a layout test in this patch as I didn't see any way to test popups via DRT.

[Mark Rowe (bdash)]

Landed in r19961.

[David Kilzer (:ddkilzer)]

(In reply to comment #9)
> I didn't include a layout test in this patch as I didn't see any way to test
> popups via DRT.

Do we need a separate bug to implement this feature in DRT?  Should DRT be dumping the list of pop-up menu items in each pop-up?  What should happen in text mode versus layout mode?

[Mark Rowe (bdash)]

I meant popups in the sense of popup windows created via window.open.

[David Kilzer (:ddkilzer)]

Mass removal of NeedsRadar keyword from my bugs that have already been RESOLVED.

[Frances Cornwall]

*** Bug 12540 has been marked as a duplicate of this bug. ***