Regexp: Fix overflow in min-match-length calculation. Crbug=126412.

Review URL: https://chromiumcodereview.appspot.com/10384053

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11525 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/ast.cc

@@ -962,6 +962,14 @@ RegExpDisjunction::RegExpDisjunction(ZoneList<RegExpTree*>* alternatives)
 }
 
 
+static int IncreaseBy(int previous, int increase) {
+  if (RegExpTree::kInfinity - previous < increase) {
+    return RegExpTree::kInfinity;
+  } else {
+    return previous + increase;
+  }
+}
+
 RegExpAlternative::RegExpAlternative(ZoneList<RegExpTree*>* nodes)
     : nodes_(nodes) {
   ASSERT(nodes->length() > 1);
@@ -969,13 +977,10 @@ RegExpAlternative::RegExpAlternative(ZoneList<RegExpTree*>* nodes)
   max_match_ = 0;
   for (int i = 0; i < nodes->length(); i++) {
     RegExpTree* node = nodes->at(i);
-    min_match_ += node->min_match();
+    int node_min_match = node->min_match();
+    min_match_ = IncreaseBy(min_match_, node_min_match);
     int node_max_match = node->max_match();
-    if (kInfinity - max_match_ < node_max_match) {
-      max_match_ = kInfinity;
-    } else {
-      max_match_ += node->max_match();
-    }
+    max_match_ = IncreaseBy(max_match_, node_max_match);
   }
 }
 

test/mjsunit/regress/regress-126412.js

+// Copyright 2012 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"".match(/(A{9999999999}B|C*)*D/);
+"C".match(/(A{9999999999}B|C*)*D/);
+"".match(/(A{9999999999}B|C*)*/ );
+"C".match(/(A{9999999999}B|C*)*/ );
+"".match(/(9u|(2\`shj{2147483649,}\r|3|f|y|3*)+8\B)\W93+/);
+"9u8 ".match(/(9u|(2\`shj{2147483649,}\r|3|f|y|3*)+8\B)\W93+/);