Make sure that the minimum font sizes are measured in points, not pixels. Should fix problems on sites like cn.yahoo.com which have some small chinese glyphs. Not part of the default build.

gfx/src/gtk/nsFontMetricsPango.cpp

@@ -176,13 +176,13 @@ nsFontMetricsPango::Init(const nsFont& aFont, nsIAtom* aLangGroup,
 
     // Hang on to the device context
     mDeviceContext = aContext;
-
-    mPixelSize = NSTwipsToFloatPoints(mFont->size);
+    
+    mPointSize = NSTwipsToFloatPoints(mFont->size);
 
     // Make sure to clamp the pixel size to something reasonable so we
     // don't make the X server blow up.
     nscoord screenPixels = gdk_screen_height();
-    mPixelSize = PR_MIN(screenPixels * FONT_MAX_FONT_SCALE, mPixelSize);
+    mPointSize = PR_MIN(screenPixels * FONT_MAX_FONT_SCALE, mPointSize);
 
     // enumerate over the font names passed in
     mFont->EnumerateFamilies(nsFontMetricsPango::EnumFontCallback, this);
@@ -222,26 +222,32 @@ nsFontMetricsPango::Init(const nsFont& aFont, nsIAtom* aLangGroup,
 
         name.Append(langGroup);
 
-        PRInt32 minimum = 0;
+        PRInt32 minimumInt = 0;
+        float minimum;
         nsresult res;
-        res = prefService->GetIntPref(name.get(), &minimum);
+        res = prefService->GetIntPref(name.get(), &minimumInt);
         if (NS_FAILED(res))
-            prefService->GetDefaultIntPref(name.get(), &minimum);
+            prefService->GetDefaultIntPref(name.get(), &minimumInt);
 
-        if (minimum < 0)
-            minimum = 0;
+        if (minimumInt < 0)
+            minimumInt = 0;
 
-        if (mPixelSize < minimum)
-            mPixelSize = minimum;
+        minimum = minimumInt;
+
+        // The minimum size is specified in pixels, not in points.
+        // Convert the size from pixels to points.
+        minimum = NSTwipsToFloatPoints(NSFloatPixelsToTwips(minimum, mDeviceContext->DevUnitsToAppUnits()));
+        if (mPointSize < minimum)
+            mPointSize = minimum;
     }
 
     // Make sure that the pixel size is at least greater than zero
-    if (mPixelSize < 1) {
+    if (mPointSize < 1) {
 #ifdef DEBUG
-        printf("*** Warning: nsFontMetricsPango created with pixel size %f\n",
-               mPixelSize);
+        printf("*** Warning: nsFontMetricsPango created with point size %f\n",
+               mPointSize);
 #endif
-        mPixelSize = 1;
+        mPointSize = 1;
     }
 
     nsresult rv = RealizeFont();
@@ -988,11 +994,8 @@ nsFontMetricsPango::RealizeFont(void)
                                       familyList.get());
 
     // Set the point size
-    // We've done some round-tripping of floating point numbers so they
-    // might not be quite right.  Since Xft rounds down, add a little,
-    // so we don't go from 9.00000 to 8.99999 to 8.
     pango_font_description_set_size(mPangoFontDesc,
-                                (gint)((mPixelSize + 0.000001) * PANGO_SCALE));
+                                    (gint)(mPointSize * PANGO_SCALE));
 
     // Set the style
     pango_font_description_set_style(mPangoFontDesc,

gfx/src/gtk/nsFontMetricsPango.h

@@ -212,7 +212,7 @@ private:
     nsCOMPtr<nsIAtom>    mLangGroup;
     nsCString           *mGenericFont;
     nsFont              *mFont;
-    float                mPixelSize;
+    float                mPointSize;
 
     nsCAutoString        mDefaultFont;