This adds an additional condition on my previous patch in r183 which tried to fix box characters appearing in some pages, such as Gmail.

The problem is that the newline character is treated as a zero-width space in the old patch, but apparently WebKit relies on this turning into a space (or something, I don't totally understand). I just removed control characters from this condition since we don't actually want to change their behavior in this respect.

webkit=https://bugs.webkit.org/show_bug.cgi?id=20237
BUG=1166024

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@204 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 39 insertions, 1 deletions

diff --git a/webkit/pending/SimpleFontData.cpp b/webkit/pending/SimpleFontData.cpp
index 9f4037b..7cf3a4d 100644
--- a/webkit/pending/SimpleFontData.cpp
+++ b/webkit/pending/SimpleFontData.cpp
@@ -30,6 +30,7 @@
 #include "config.h"
 #include "SimpleFontData.h"
 
+#include "Font.h"
 #include "FontMetrics.h"
 
 #if ENABLE(SVG_FONTS)
@@ -149,6 +150,21 @@ float SimpleFontData::widthForGlyph(UChar32 c, Glyph glyph) const
     }
 #endif
 
+    // Some characters should be zero width and we want to ignore whatever
+    // crazy stuff the font may have (or not defined). If the font doesn't
+    // define it, we don't want to measure the width of the "invalid character"
+    // box, for example.
+    //
+    // Note that we have to exempt control characters, which
+    // treatAsZeroWidthSpace would normally return true for. This is primarily
+    // for \n since it will be rendered as a regular space in HTML.
+    //
+    // TODO(brettw): we should have Font::treatAsZeroWidthSpace return true for
+    // zero width spaces (U+200B) just like Font::treatAsSpace will return true
+    // for spaces. Then the additional OR is not necessary.
+    if (c > ' ' && (Font::treatAsZeroWidthSpace(c) || c == 0x200b))
+      return 0.0f;
+
     if (width != cGlyphWidthUnknown)
         return width;
 
diff --git a/webkit/port/platform/graphics/GlyphPageTreeNodeWin.cpp b/webkit/port/platform/graphics/GlyphPageTreeNodeWin.cpp
index 65d1350..70ceaac 100644
--- a/webkit/port/platform/graphics/GlyphPageTreeNodeWin.cpp
+++ b/webkit/port/platform/graphics/GlyphPageTreeNodeWin.cpp
@@ -32,6 +32,7 @@
 #include <windows.h>
 #include <vector>
 
+#include "Font.h"
 #include "GlyphPageTreeNode.h"
 #include "SimpleFontData.h"
 #include "UniscribeStateTextRun.h"
@@ -145,8 +146,29 @@ static bool FillBMPGlyphs(UChar* buffer,
         !(tm.tmPitchAndFamily & TMPF_TRUETYPE))
       invalid_glyph = 0x1F;
 
+    WORD space_glyph = 0;  // Glyph for a space. Lazily filled, see below.
+
     for (unsigned i = 0; i < GlyphPage::size; i++) {
-        if (localGlyphBuffer[i] == invalid_glyph) {
+        // When this character should be a space, we ignore whatever the font
+        // says and use a space. Otherwise, if fonts don't map one of these
+        // space or zero width glyphs, we will get a box.
+        //
+        // TODO(brettw): we should have Font::treatAsZeroWidthSpace return true
+        // for zero width spaces (U+200B) just like Font::treatAsSpace will
+        // return true for spaces. Then the additional OR is not necessary.
+        if (buffer[i] > ' ' &&
+            (Font::treatAsSpace(buffer[i]) ||
+             Font::treatAsZeroWidthSpace(buffer[i]) ||
+             buffer[i] == 0x200B)) {
+            // Hard code the glyph indices for characters that should be treated
+            // like spaces.
+            if (!space_glyph) {
+                // Get the glyph index for space.
+                wchar_t space = ' ';
+                GetGlyphIndices(dc, &space, 1, &space_glyph, 0);
+            }
+            page->setGlyphDataForIndex(i, space_glyph, fontData);
+        } else if (localGlyphBuffer[i] == invalid_glyph) {
             // WebKit expects both the glyph index and FontData
             // pointer to be NULL if the glyph is not present
             page->setGlyphDataForIndex(i, 0, 0);