1 files changed, 10 insertions, 7 deletions
diff --git a/src/3rdparty/webkit/JavaScriptCore/runtime/RegExpPrototype.cpp b/src/3rdparty/webkit/JavaScriptCore/runtime/RegExpPrototype.cpp
index bbc9e85b57..dd5fe0252f 100644
--- a/src/3rdparty/webkit/JavaScriptCore/runtime/RegExpPrototype.cpp
+++ b/src/3rdparty/webkit/JavaScriptCore/runtime/RegExpPrototype.cpp
@@ -27,6 +27,7 @@
 #include "JSFunction.h"
 #include "JSObject.h"
 #include "JSString.h"
+#include "JSStringBuilder.h"
 #include "JSValue.h"
 #include "ObjectPrototype.h"
 #include "PrototypeFunction.h"
@@ -91,7 +92,7 @@ JSValue JSC_HOST_CALL regExpProtoFuncCompile(ExecState* exec, JSObject*, JSValue
     }
 
     if (!regExp->isValid())
-        return throwError(exec, SyntaxError, UString("Invalid regular expression: ").append(regExp->errorMessage()));
+        return throwError(exec, SyntaxError, makeString("Invalid regular expression: ", regExp->errorMessage()));
 
     asRegExpObject(thisValue)->setRegExp(regExp.release());
     asRegExpObject(thisValue)->setLastIndex(0);
@@ -106,15 +107,17 @@ JSValue JSC_HOST_CALL regExpProtoFuncToString(ExecState* exec, JSObject*, JSValu
         return throwError(exec, TypeError);
     }
 
-    UString result = "/" + asRegExpObject(thisValue)->get(exec, exec->propertyNames().source).toString(exec);
-    result.append('/');
+    char postfix[5] = { '/', 0, 0, 0, 0 };
+    int index = 1;
     if (asRegExpObject(thisValue)->get(exec, exec->propertyNames().global).toBoolean(exec))
-        result.append('g');
+        postfix[index++] = 'g';
     if (asRegExpObject(thisValue)->get(exec, exec->propertyNames().ignoreCase).toBoolean(exec))
-        result.append('i');
+        postfix[index++] = 'i';
     if (asRegExpObject(thisValue)->get(exec, exec->propertyNames().multiline).toBoolean(exec))
-        result.append('m');
-    return jsNontrivialString(exec, result);
+        postfix[index] = 'm';
+    UString source = asRegExpObject(thisValue)->get(exec, exec->propertyNames().source).toString(exec);
+    // If source is empty, use "/(?:)/" to avoid colliding with comment syntax
+    return jsMakeNontrivialString(exec, "/", source.size() ? source : UString("(?:)"), postfix);
 }
 
 } // namespace JSC