From 5e7859bd23342abdaf3587c99cda693eb4d46213 Mon Sep 17 00:00:00 2001
From: Shu-yu Guo <shu@rfrn.org>
Date: Mon, 20 Aug 2012 22:02:18 -0700
Subject: [PATCH] Bug 784015 - Fix division by 0 when calling
 ParallelArray.prototype.partition (r=dmandelin)

---
 js/src/builtin/ParallelArray.cpp                        | 2 +-
 js/src/jit-test/tests/parallelarray/partition-throws.js | 6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/js/src/builtin/ParallelArray.cpp b/js/src/builtin/ParallelArray.cpp
index 7299a1c02f3..e9c8eceb9f5 100644
--- a/js/src/builtin/ParallelArray.cpp
+++ b/js/src/builtin/ParallelArray.cpp
@@ -1366,7 +1366,7 @@ ParallelArrayObject::partition(JSContext *cx, CallArgs args)
 
     // Throw if the outer dimension is not divisible by the new dimension.
     uint32_t outer = obj->outermostDimension();
-    if (outer % newDimension) {
+    if (newDimension == 0 || outer % newDimension) {
         JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_PAR_ARRAY_BAD_PARTITION);
         return false;
     }
diff --git a/js/src/jit-test/tests/parallelarray/partition-throws.js b/js/src/jit-test/tests/parallelarray/partition-throws.js
index 4361207ffc9..c0c3548f56a 100644
--- a/js/src/jit-test/tests/parallelarray/partition-throws.js
+++ b/js/src/jit-test/tests/parallelarray/partition-throws.js
@@ -1,8 +1,10 @@
-// |jit-test| error: Error;
+load(libdir + "asserts.js");
 
 function testPartitionDivisible() {
   var p = new ParallelArray([1,2,3,4]);
-  var pp = p.partition(3);
+  var pp;
+  assertThrowsInstanceOf(function () { pp = p.partition(3); }, Error);
+  assertThrowsInstanceOf(function () { pp = p.partition(.34); }, Error);
 }
 
 testPartitionDivisible();