Elements whose contents start with an astral Unicode symbol disappear when CSS `::first-letter` is …

Source/platform/text/TextBreakIterator.cpp

Index: Source/platform/text/TextBreakIterator.cpp
diff --git a/Source/platform/text/TextBreakIterator.cpp b/Source/platform/text/TextBreakIterator.cpp
index ec97484b4650a36532906ddba5e4b44967494ada..e744726cef8d6a475c38d7e83989eb04e34b7dde 100644
--- a/Source/platform/text/TextBreakIterator.cpp
+++ b/Source/platform/text/TextBreakIterator.cpp
@@ -50,6 +50,27 @@ unsigned numGraphemeClusters(const String& string)
     return num;
 }
 
+unsigned numCharactersInGraphemeClusters(const String& string, unsigned numGraphemeClusters)

[eae, 2015/05/14 23:52:48]

We already have an implementation of this in HarfBuzzShaper,
countGraphemesInCluster. How about we move that implementation into
TextBreakIterator and make it a static function? That way the implementation can
be shared.

[changseok, 2015/05/15 17:08:56]

Sorry, I can't follow this meaning. Do you want anything like..
static unsigned countGraphemesInCluster()
{
    ....
}

unsigned numCharactersInGraphemeClutters()
{
    ....
    return countGraphemesInClusters();
}

??

+{
+    unsigned stringLength = string.length();
+
+    if (!stringLength)
+        return 0;
+
+    // The only Latin-1 Extended Grapheme Cluster is CR LF
+    if (string.is8Bit() && !string.contains('\r'))
+        return std::min(stringLength, numGraphemeClusters);
+
+    NonSharedCharacterBreakIterator it(string);
+    if (!it)
+        return std::min(stringLength, numGraphemeClusters);
+
+    for (unsigned i = 0; i < numGraphemeClusters; ++i) {
+        if (it.next() == TextBreakDone)
+            return stringLength;
+    }
+    return it.current();
+}
 
 static inline bool isBreakableSpace(UChar ch)
 {