26453 2009-06-16 13:07:01 -0700 Null Cairo context will crash Windows Cairo Build 2009-06-16 13:31:25 -0700 1 1 1 Unclassified WebKit WebKit Misc. 528+ (Nightly build) PC Windows XP RESOLVED FIXED P2 Normal --- 1 bfulgham webkit-unassigned oldest_to_newest 126266 0 bfulgham 2009-06-16 13:07:01 -0700 The DRT test suite identified a crash bug in the Windows Cairo build. If a null platform graphics context is passed to the GraphicsContext constructor, e.g., from Line 3724 in RenderBlock.cpp: GraphicsContext context((PlatformGraphicsContext*)0); The internal Windows Cairo sync function (which attempts to keep the Windows DC in sync with the Cairo one) will crash when it attempts to retrieve the Cairo surface from the null pointer (see Line 180 in GraphicsContextCairoWin.cpp): cairo_surface_t* surface = cairo_get_target(cr); The fix is to check for a null pointer before attempting to do so. 126271 1 31367 bfulgham 2009-06-16 13:13:02 -0700 Created attachment 31367 Null check. 126273 2 31367 xan.lopez 2009-06-16 13:24:04 -0700 Comment on attachment 31367 Null check. r=me 126274 3 bfulgham 2009-06-16 13:31:25 -0700 Landed in http://trac.webkit.org/changeset/44734 31367 2009-06-16 13:13:02 -0700 2009-06-16 13:24:04 -0700 Null check. null_cr_crash.patch text/plain 1351 bfulgham SW5kZXg6IFdlYkNvcmUvQ2hhbmdlTG9nCj09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0KLS0tIFdlYkNvcmUvQ2hhbmdlTG9n CShyZXZpc2lvbiA0NDczMykKKysrIFdlYkNvcmUvQ2hhbmdlTG9nCSh3b3JraW5nIGNvcHkpCkBA IC0xLDMgKzEsMTcgQEAKKzIwMDktMDYtMTYgIEJyZW50IEZ1bGdoYW0gIDxiZnVsZ2hhbUB3ZWJr aXQub3JnPgorCisgICAgICAgIFJldmlld2VkIGJ5IE5PQk9EWSAoT09QUyEpLgorCisgICAgICAg IFRlc3Q6IGZhc3QvbXVsdGljb2wvY29sdW1ucy1zaG9ydGhhbmQtcGFyc2luZy5odG1sIAorCisg ICAgICAgIEZpeGVzIGh0dHBzOi8vYnVncy53ZWJraXQub3JnL3Nob3dfYnVnLmNnaT9pZD0yNjQ1 My4KKyAgICAgICAgTnVsbCBDYWlybyBjb250ZXh0d2lsbCBjcmFzaCBXaW5kb3dzIENhaXJvIGJ1 aWxkLgorCisgICAgICAgICogcGxhdGZvcm0vZ3JhcGhpY3Mvd2luL0dyYXBoaWNzQ29udGV4dENh aXJvV2luLmNwcDoKKyAgICAgICAgKFdlYkNvcmU6OkdyYXBoaWNzQ29udGV4dFBsYXRmb3JtUHJp dmF0ZTo6c3luY0NvbnRleHQpOgorICAgICAgICAgIEFkZCBhIGNoZWNrIGZvciBudWxsIGNvbnRl eHQgYmVmb3JlIGF0dGVtcHRpbmcgdG8KKyAgICAgICAgICByZXRyaWV2ZSB0aGUgQ2Fpcm8gc3Vy ZmFjZS4KKwogMjAwOS0wNi0xNiAgUGV0ZXIgS2FzdGluZyAgPHBrYXN0aW5nQGdvb2dsZS5jb20+ CiAKICAgICAgICAgUmV2aWV3ZWQgYnkgWGFuIExvcGV6LgpJbmRleDogV2ViQ29yZS9wbGF0Zm9y bS9ncmFwaGljcy93aW4vR3JhcGhpY3NDb250ZXh0Q2Fpcm9XaW4uY3BwCj09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0KLS0t IFdlYkNvcmUvcGxhdGZvcm0vZ3JhcGhpY3Mvd2luL0dyYXBoaWNzQ29udGV4dENhaXJvV2luLmNw cAkocmV2aXNpb24gNDQ3MzMpCisrKyBXZWJDb3JlL3BsYXRmb3JtL2dyYXBoaWNzL3dpbi9HcmFw aGljc0NvbnRleHRDYWlyb1dpbi5jcHAJKHdvcmtpbmcgY29weSkKQEAgLTIxMSw2ICsyMTEsOSBA QCB2b2lkIEdyYXBoaWNzQ29udGV4dFBsYXRmb3JtUHJpdmF0ZTo6Y29uCiAKIHZvaWQgR3JhcGhp Y3NDb250ZXh0UGxhdGZvcm1Qcml2YXRlOjpzeW5jQ29udGV4dChQbGF0Zm9ybUdyYXBoaWNzQ29u dGV4dCogY3IpCiB7CisgICAgaWYgKCFjcikKKyAgICAgICByZXR1cm47CisKICAgICBjYWlyb19z dXJmYWNlX3QqIHN1cmZhY2UgPSBjYWlyb19nZXRfdGFyZ2V0KGNyKTsKICAgICBtX2hkYyA9IGNh aXJvX3dpbjMyX3N1cmZhY2VfZ2V0X2RjKHN1cmZhY2UpOyAgIAogCg==