Linux: fix double italic on some fonts.

If we ask fontconfig for an italic font, it might take a roman font
and set the undocumented property FC_MATRIX to a skew matrix. It'll
then say that the font is italic or oblique. So, if we see a matrix,
we don't believe that it's italic.

BUG=15212

http://codereview.chromium.org/147108


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@19184 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 15 insertions, 2 deletions

diff --git a/skia/ext/SkFontHost_fontconfig_direct.cpp b/skia/ext/SkFontHost_fontconfig_direct.cpp
index dc20aff..a732d06 100644
--- a/skia/ext/SkFontHost_fontconfig_direct.cpp
+++ b/skia/ext/SkFontHost_fontconfig_direct.cpp
@@ -179,10 +179,23 @@ bool FontConfigDirect::Match(std::string* result_family,
     if (FcPatternGetInteger(match, FC_SLANT, 0, &resulting_italic))
       resulting_italic = FC_SLANT_ROMAN;
 
+    // If we ask for an italic font, fontconfig might take a roman font and set
+    // the undocumented property FC_MATRIX to a skew matrix. It'll then say
+    // that the font is italic or oblique. So, if we see a matrix, we don't
+    // believe that it's italic.
+    FcValue matrix;
+    const bool have_matrix = FcPatternGet(match, FC_MATRIX, 0, &matrix) == 0;
+
+    // If we ask for an italic font, fontconfig might take a roman font and set
+    // FC_EMBOLDEN.
+    FcValue embolden;
+    const bool have_embolden =
+        FcPatternGet(match, FC_EMBOLDEN, 0, &embolden) == 0;
+
     if (is_bold)
-      *is_bold = resulting_bold >= FC_WEIGHT_BOLD;
+      *is_bold = resulting_bold >= FC_WEIGHT_BOLD && !have_embolden;
     if (is_italic)
-      *is_italic = resulting_italic == FC_SLANT_ITALIC;
+      *is_italic = resulting_italic > FC_SLANT_ROMAN && !have_matrix;
 
     if (result_family)
         *result_family = (char *) c_family;