Bug 37747 – Crash in FontFallbackList::determinePitch

• Component: Layout and Rendering
• Status: RESOLVED FIXED

[张晓明]

On Windows 7 Platform,Get Nightly build r57720, 
Build and run WinLanucher.exe, it will crash every time。

debugging it in Visual Studio 20005, find that the problem is caused by this function

void FontFallbackList::determinePitch(const Font* font) const
{
    const FontData* fontData = primaryFontData(font);
    if (!fontData->isSegmented())
        m_pitch = static_cast<const SimpleFontData*>(fontData)->pitch();
    else {
        const SegmentedFontData* segmentedFontData = static_cast<const SegmentedFontData*>(fontData);
        unsigned numRanges = segmentedFontData->numRanges();
        if (numRanges == 1)
            m_pitch = segmentedFontData->rangeAt(0).fontData()->pitch();
        else
            m_pitch = VariablePitch;
    }
} 

fontData is NULL every time。

I Step into primaryFontData() and find the real reason is the following funciont

void FontPlatformData::platformDataInit(HFONT font, float size, HDC hdc, WCHAR* faceName)
{
    LOGFONT logfont;
    GetObject(font, sizeof(logfont), &logfont);
    m_cgFont.adoptCF(CGFontCreateWithPlatformFont(&logfont));
}

this function is in webkit\webcore\platform\graphics\win\FontPlatformDataCGWin.cpp,

this function is modified at revision 55975。before this revison, this crash not occured。

Thanks for the bug report! Do you have Safari 4.0.5 installed? <http://trac.webkit.org/changeset/55975> made it so that WebKit requires the version of Core Graphics that comes with Safari 4.0.5.

[张晓明]

Get a new version of CoreGraphics.dll from safari 4.0.5, the problem is resolved。thanks for the comments from [e-mail]!:）