Changeset 73116 in webkit

Timestamp:

Dec 2, 2010 1:54:24 AM (13 years ago)

Author:

commit-queue@webkit.org

Message:

2010-12-02 Hironori Bono <​hbono@chromium.org>

Reviewed by Darin Fisher.

[Chromium] Fix possible crashes in FontFallbackFont::determinePitch().
​https://bugs.webkit.org/show_bug.cgi?id=25770

When all of "Arial", "Courier New", and "Times New Roman" fonts are corrupted,
FontCache::getLastResortFallbackFont() returns 0 and it causes this crash. To
avoid this crash, this change falls back to system fonts (Windows ensures they
are sane) as Win Safari does. Unfortunately, I don't have any ideas how I can
write a layout test for this issue because this crash happens on a PC some of
its system fonts are corrupted.

• platform/graphics/chromium/FontCacheChromiumWin.cpp: (WebCore::fontDataFromDescriptionAndLogFont): (WebCore::FontCache::getLastResortFallbackFont):

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/chromium/FontCacheChromiumWin.cpp (modified) (2 diffs)

trunk/WebCore/ChangeLog

@@ +1 @@
+2010-12-02  Hironori Bono  <hbono@chromium.org>
+
+        Reviewed by Darin Fisher.
+
+        [Chromium] Fix possible crashes in FontFallbackFont::determinePitch().
+        https://bugs.webkit.org/show_bug.cgi?id=25770
+
+        When all of "Arial", "Courier New", and "Times New Roman" fonts are corrupted,
+        FontCache::getLastResortFallbackFont() returns 0 and it causes this crash. To
+        avoid this crash, this change falls back to system fonts (Windows ensures they
+        are sane) as Win Safari does. Unfortunately, I don't have any ideas how I can
+        write a layout test for this issue because this crash happens on a PC some of
+        its system fonts are corrupted.
+
+        * platform/graphics/chromium/FontCacheChromiumWin.cpp:
+        (WebCore::fontDataFromDescriptionAndLogFont):
+        (WebCore::FontCache::getLastResortFallbackFont):
+
 2010-12-02  Dimitri Glazkov  <dglazkov@chromium.org>
 

trunk/WebCore/platform/graphics/chromium/FontCacheChromiumWin.cpp

@@ -422 +422 @@
 }
 
+// Tries the given font and save it |outFontFamilyName| if it succeeds.
+static SimpleFontData* fontDataFromDescriptionAndLogFont(FontCache* fontCache, const FontDescription& fontDescription, const LOGFONT& font, wchar_t* outFontFamilyName)
+{
+    SimpleFontData* fontData = fontCache->getCachedFontData(fontDescription, font.lfFaceName);
+    if (fontData)
+        memcpy(outFontFamilyName, font.lfFaceName, sizeof(font.lfFaceName));
+    return fontData;
+}
+
 SimpleFontData* FontCache::getLastResortFallbackFont(const FontDescription& description)
 {
@@ -439 +448 @@
         fontStr = courierStr;
 
-    return getCachedFontData(description, fontStr);
+    SimpleFontData* simpleFont = getCachedFontData(description, fontStr);
+    if (simpleFont)
+        return simpleFont;
+
+    // Fall back to system fonts as Win Safari does because this function must
+    // return a valid font. Once we find a valid system font, we save its name
+    // to a static variable and use it to prevent trying system fonts again.
+    static wchar_t fallbackFontName[LF_FACESIZE] = {0};
+    if (fallbackFontName[0])
+        return getCachedFontData(description, fallbackFontName);
+
+    // Fall back to the DEFAULT_GUI_FONT if no known Unicode fonts are available.
+    if (HFONT defaultGUIFont = static_cast<HFONT>(GetStockObject(DEFAULT_GUI_FONT))) {
+        LOGFONT defaultGUILogFont;
+        GetObject(defaultGUIFont, sizeof(defaultGUILogFont), &defaultGUILogFont);
+        if (simpleFont = fontDataFromDescriptionAndLogFont(this, description, defaultGUILogFont, fallbackFontName))
+            return simpleFont;
+    }
+
+    // Fall back to Non-client metrics fonts.
+    NONCLIENTMETRICS nonClientMetrics = {0};
+    nonClientMetrics.cbSize = sizeof(nonClientMetrics);
+    if (SystemParametersInfo(SPI_GETNONCLIENTMETRICS, sizeof(nonClientMetrics), &nonClientMetrics, 0)) {
+        if (simpleFont = fontDataFromDescriptionAndLogFont(this, description, nonClientMetrics.lfMessageFont, fallbackFontName))
+            return simpleFont;
+        if (simpleFont = fontDataFromDescriptionAndLogFont(this, description, nonClientMetrics.lfMenuFont, fallbackFontName))
+            return simpleFont;
+        if (simpleFont = fontDataFromDescriptionAndLogFont(this, description, nonClientMetrics.lfStatusFont, fallbackFontName))
+            return simpleFont;
+        if (simpleFont = fontDataFromDescriptionAndLogFont(this, description, nonClientMetrics.lfCaptionFont, fallbackFontName))
+            return simpleFont;
+        if (simpleFont = fontDataFromDescriptionAndLogFont(this, description, nonClientMetrics.lfSmCaptionFont, fallbackFontName))
+            return simpleFont;
+    }
+
+    ASSERT_NOT_REACHED();
+    return 0;
 }