1 files changed, 40 insertions, 8 deletions
diff --git a/chromium/third_party/WebKit/Source/wtf/text/StringBuilder.cpp b/chromium/third_party/WebKit/Source/wtf/text/StringBuilder.cpp
index 0e3d82d58e1..9236bf6fb55 100644
--- a/chromium/third_party/WebKit/Source/wtf/text/StringBuilder.cpp
+++ b/chromium/third_party/WebKit/Source/wtf/text/StringBuilder.cpp
@@ -29,6 +29,7 @@
 
 #include "IntegerToStringConversion.h"
 #include "WTFString.h"
+#include "wtf/dtoa.h"
 
 namespace WTF {
 
@@ -166,9 +167,10 @@ void StringBuilder::reallocateBuffer<LChar>(unsigned requiredLength)
     ASSERT(m_is8Bit);
     ASSERT(m_buffer->is8Bit());
 
-    if (m_buffer->hasOneRef())
-        m_buffer = StringImpl::reallocate(m_buffer.release(), requiredLength, m_bufferCharacters8);
-    else
+    if (m_buffer->hasOneRef()) {
+        m_buffer = StringImpl::reallocate(m_buffer.release(), requiredLength);
+        m_bufferCharacters8 = const_cast<LChar*>(m_buffer->characters8());
+    } else
         allocateBuffer(m_buffer->characters8(), requiredLength);
 }
 
@@ -179,11 +181,12 @@ void StringBuilder::reallocateBuffer<UChar>(unsigned requiredLength)
     // otherwise fall back to "allocate and copy" method.
     m_string = String();
 
-    if (m_buffer->is8Bit())
+    if (m_buffer->is8Bit()) {
         allocateBufferUpConvert(m_buffer->characters8(), requiredLength);
-    else if (m_buffer->hasOneRef())
-        m_buffer = StringImpl::reallocate(m_buffer.release(), requiredLength, m_bufferCharacters16);
-    else
+    } else if (m_buffer->hasOneRef()) {
+        m_buffer = StringImpl::reallocate(m_buffer.release(), requiredLength);
+        m_bufferCharacters16 = const_cast<UChar*>(m_buffer->characters16());
+    } else
         allocateBuffer(m_buffer->characters16(), requiredLength);
 }
 
@@ -319,7 +322,7 @@ void StringBuilder::appendNumber(int number)
     numberToStringSigned<StringBuilder>(number, this);
 }
 
-void StringBuilder::appendNumber(unsigned int number)
+void StringBuilder::appendNumber(unsigned number)
 {
     numberToStringUnsigned<StringBuilder>(number, this);
 }
@@ -344,6 +347,35 @@ void StringBuilder::appendNumber(unsigned long long number)
     numberToStringUnsigned<StringBuilder>(number, this);
 }
 
+static void expandLCharToUCharInplace(UChar* buffer, size_t length)
+{
+    const LChar* sourceEnd = reinterpret_cast<LChar*>(buffer) + length;
+    UChar* current = buffer + length;
+    while (current != buffer)
+        *--current = *--sourceEnd;
+}
+
+void StringBuilder::appendNumber(double number, unsigned precision, TrailingZerosTruncatingPolicy trailingZerosTruncatingPolicy)
+{
+    bool truncateTrailingZeros = trailingZerosTruncatingPolicy == TruncateTrailingZeros;
+    size_t numberLength;
+    if (m_is8Bit) {
+        LChar* dest = appendUninitialized<LChar>(NumberToStringBufferLength);
+        const char* result = numberToFixedPrecisionString(number, precision, reinterpret_cast<char*>(dest), truncateTrailingZeros);
+        numberLength = strlen(result);
+    } else {
+        UChar* dest = appendUninitialized<UChar>(NumberToStringBufferLength);
+        const char* result = numberToFixedPrecisionString(number, precision, reinterpret_cast<char*>(dest), truncateTrailingZeros);
+        numberLength = strlen(result);
+        expandLCharToUCharInplace(dest, numberLength);
+    }
+    ASSERT(m_length >= NumberToStringBufferLength);
+    // Remove what appendUninitialized added.
+    m_length -= NumberToStringBufferLength;
+    ASSERT(numberLength <= NumberToStringBufferLength);
+    m_length += numberLength;
+}
+
 bool StringBuilder::canShrink() const
 {
     // Only shrink the buffer if it's less than 80% full. Need to tune this heuristic!