Make String.prototype.split honor limit when separator is empty.

BUG=929

Review URL: http://codereview.chromium.org/4750003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5806 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/runtime.cc

@@ -5020,11 +5020,12 @@ static int CopyCachedAsciiCharsToArray(const char* chars,
 // For example, "foo" => ["f", "o", "o"].
 static MaybeObject* Runtime_StringToArray(Arguments args) {
   HandleScope scope;
-  ASSERT(args.length() == 1);
+  ASSERT(args.length() == 2);
   CONVERT_ARG_CHECKED(String, s, 0);
+  CONVERT_NUMBER_CHECKED(uint32_t, limit, Uint32, args[1]);
 
   s->TryFlatten();
-  const int length = s->length();
+  const int length = static_cast<int>(Min<uint32_t>(s->length(), limit));
 
   Handle<FixedArray> elements;
   if (s->IsFlat() && s->IsAsciiRepresentation()) {

src/runtime.h

@@ -175,7 +175,7 @@ namespace internal {
   F(StringReplaceRegExpWithString, 4, 1) \
   F(StringMatch, 3, 1) \
   F(StringTrim, 3, 1) \
-  F(StringToArray, 1, 1) \
+  F(StringToArray, 2, 1) \
   F(NewStringWrapper, 1, 1) \
   \
   /* Numbers */ \

src/string.js

@@ -552,7 +552,7 @@ function StringSplit(separator, limit) {
     var separator_length = separator.length;
 
     // If the separator string is empty then return the elements in the subject.
-    if (separator_length === 0) return %StringToArray(subject);
+    if (separator_length === 0) return %StringToArray(subject, limit);
 
     var result = %StringSplit(subject, separator, limit);
 

test/mjsunit/string-split.js

@@ -97,3 +97,22 @@ assertEquals([""], ''.split(/./));
 assertEquals([], ''.split(/.?/));
 assertEquals([], ''.split(/.??/));
 assertEquals([], ''.split(/()()/));
+
+
+// Issue http://code.google.com/p/v8/issues/detail?id=929
+// (Splitting with empty separator and a limit.)
+
+function numberObj(num) {
+  return {valueOf: function() { return num; }};
+}
+
+assertEquals([], "abc".split("", 0));
+assertEquals([], "abc".split("", numberObj(0)));
+assertEquals(["a"], "abc".split("", 1));
+assertEquals(["a"], "abc".split("", numberObj(1)));
+assertEquals(["a", "b"], "abc".split("", 2));
+assertEquals(["a", "b"], "abc".split("", numberObj(2)));
+assertEquals(["a", "b", "c"], "abc".split("", 3));
+assertEquals(["a", "b", "c"], "abc".split("", numberObj(3)));
+assertEquals(["a", "b", "c"], "abc".split("", 4));
+assertEquals(["a", "b", "c"], "abc".split("", numberObj(4)));