Remapped regexp last-match-info to put subject and index before match indices.

src/jsregexp.cc

Index: src/jsregexp.cc
diff --git a/src/jsregexp.cc b/src/jsregexp.cc
index 7acf639b524c40d4e787b7956b9447a25071efb9..068b0a7549ef99e1b996c88c4550011308c20b84 100644
--- a/src/jsregexp.cc
+++ b/src/jsregexp.cc
@@ -307,9 +307,10 @@ Handle<Object> RegExpImpl::AtomExecGlobal(Handle<JSRegExp> re,
     // that is attached to the global RegExp object.  We will be returning
     // an array of these.
     Handle<FixedArray> array = Factory::NewFixedArray(kFirstCapture + 2);
+    SetLastCaptureCount(*array, 2);
+    // Ignore subject and input fields.
     SetCapture(*array, 0, value);
     SetCapture(*array, 1, end);
-    SetLastCaptureCount(*array, 2);
     Handle<JSArray> pair = Factory::NewJSArrayWithElements(array);
     SetElement(result, match_count, pair);
     match_count++;
@@ -561,22 +562,22 @@ Handle<Object> RegExpImpl::IrregexpExecGlobal(Handle<JSRegExp> regexp,
         // Create an array that looks like the static last_match_info array
         // that is attached to the global RegExp object.  We will be returning
         // an array of these.
-        Handle<FixedArray> matches_array(JSArray::cast(*matches)->elements());
+        int match_length = kFirstCapture + number_of_capture_registers;
         Handle<JSArray> latest_match =
-            Factory::NewJSArray(kFirstCapture + number_of_capture_registers);
-        Handle<FixedArray> latest_match_array(latest_match->elements());
-
-        for (int i = 0; i < number_of_capture_registers; i++) {
-          SetCapture(*latest_match_array, i, GetCapture(*matches_array, i));
-        }
-        SetLastCaptureCount(*latest_match_array, number_of_capture_registers);
-
+            Factory::NewJSArray(match_length);
+
+        AssertNoAllocation no_allocation;
+        FixedArray* match_array = JSArray::cast(*matches)->elements();
+        match_array->CopyTo(0,
+                            latest_match->elements(),
+                            0,
+                            match_length);
         SetElement(result, result_length, latest_match);
         result_length++;
-        previous_index = GetCapture(*matches_array, 1);
-        if (GetCapture(*matches_array, 0) == previous_index)
+        previous_index = GetCapture(match_array, 1);
+        if (GetCapture(match_array, 0) == previous_index) {
           previous_index++;
-
+        }
       } else {
         ASSERT(matches->IsNull());
         return result;
@@ -636,18 +637,15 @@ Handle<Object> RegExpImpl::IrregexpExecOnce(Handle<FixedArray> regexp,
   }
 
   FixedArray* array = last_match_info->elements();
-  // Clear previous input/string values to avoid potential memory leak.
-  SetLastSubject(array, Heap::empty_string());
-  SetLastInput(array, Heap::empty_string());
   ASSERT(array->length() >= number_of_capture_registers + kLastMatchOverhead);
   // The captures come in (start, end+1) pairs.
-  for (int i = 0; i < number_of_capture_registers; i += 2) {
-    SetCapture(array, i, offsets_vector[i]);
-    SetCapture(array, i + 1, offsets_vector[i + 1]);
-  }
   SetLastCaptureCount(array, number_of_capture_registers);
   SetLastSubject(array, *original_subject);
   SetLastInput(array, *original_subject);
+  for (int i = 0; i < number_of_capture_registers; i+=2) {
+    SetCapture(array, i, offsets_vector[i]);
+    SetCapture(array, i + 1, offsets_vector[i + 1]);
+  }
   return last_match_info;
 }