Bug 66097 – REGRESSION: Qt JavaScript bridge signal connection fails

• Component: WebKit Qt
• Status: RESOLVED FIXED

[Andrew Wason]

Connecting to a Qt signal from JavaScript now fails.

This can be reproduced with an existing testcase:


$ WebKitBuild/Debug/WebKit/qt/tests/qwebframe/tst_qwebframe connectAndDisconnect
********* Start testing of tst_QWebFrame *********
Config: Using QTest library 4.7.3, Qt 4.7.3
PASS   : tst_QWebFrame::initTestCase()
ASSERTION FAILED: isValidThisObject(thisValue, exec)
../../../Source/JavaScriptCore/runtime/CallData.cpp(38) : JSC::JSValue JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, const JSC::CallData&, JSC::JSValue, const JSC::ArgList&)
QFATAL : tst_QWebFrame::connectAndDisconnect() Received signal 11
FAIL!  : tst_QWebFrame::connectAndDisconnect() Received a fatal error.
   Loc: [Unknown file(0)]
Totals: 1 passed, 1 failed, 0 skipped
********* Finished testing of tst_QWebFrame *********
Aborted

[Andrew Wason]

Looks like the problem was introduced with r91095 from bug 64250

[Andrew Wason]

A workaround is to pass an anonymous object as the first arg to connect, e.g.:

context.someSignal.connect({}, function() { });

Because otherwise JSC::Bindings::QtRuntimeConnectionMethod::call() uses the window object (exec->lexicalGlobalObject()) and that seems to trigger the assert.
See http://trac.webkit.org/browser/trunk/Source/WebCore/bridge/qt/qt_runtime.cpp#L1587

[Andrew Wason]

Created attachment 103719 [details]
pass toThisObject() to JS signal handler

This also re-enables tst_QWebFrame::connectAndDisconnect() tests that were disabled with bug 65170

[Gavin Barraclough]

Comment on attachment 103719 [details]
pass toThisObject() to JS signal handler

Ooops, apologies for the breakage! - thanks for the fix.

[WebKit Review Bot]

Comment on attachment 103719 [details]
pass toThisObject() to JS signal handler

Clearing flags on attachment: 103719

Committed r92907: <http://trac.webkit.org/changeset/92907>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.