Allow pathological zero-length typed arrays.

test/mjsunit/harmony/typedarrays.js

 // Copyright 2013 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
@@ skipping 173 matching lines @@
   }
 
   for (i = 0; i < 128; i++) {
     assertSame(0, a4[i]);
   }
 
   for (i = 128; i < 256; i++) {
     assertSame(typicalElement, a4[i]);
   }
 
-  assertThrows(function () { new proto(ab, 256*elementSize); }, RangeError);
+  var aAtTheEnd = new proto(ab, 256*elementSize);
+  assertSame(elementSize, aAtTheEnd.BYTES_PER_ELEMENT);
+  assertSame(0, aAtTheEnd.length);
+  assertSame(0, aAtTheEnd.byteLength);
+  assertSame(256*elementSize, aAtTheEnd.byteOffset);
+
+  assertThrows(function () { new proto(ab, 257*elementSize); }, RangeError);
   assertThrows(
       function () { new proto(ab, 128*elementSize, 192); },
       RangeError);
 
   if (elementSize !== 1) {
     assertThrows(function() { new proto(ab, 128*elementSize - 1, 10); },
                  RangeError);
     var unalignedArrayBuffer = new ArrayBuffer(10*elementSize + 1);
     var goodArray = new proto(unalignedArrayBuffer, 0, 10);
     assertSame(10, goodArray.length);
@@ skipping 17 matching lines @@
   }
   var aFromArray = new proto(jsArray);
   assertSame(elementSize, aFromArray.BYTES_PER_ELEMENT);
   assertSame(30, aFromArray.length);
   assertSame(30*elementSize, aFromArray.byteLength);
   assertSame(0, aFromArray.byteOffset);
   assertSame(30*elementSize, aFromArray.buffer.byteLength);
   for (i = 0; i < 30; i++) {
     assertSame(typicalElement, aFromArray[i]);
   }
+
+  var abLen0 = new ArrayBuffer(0);
+  var aOverAbLen0 = new proto(abLen0);
+  assertSame(abLen0, aOverAbLen0.buffer);
+  assertSame(elementSize, aOverAbLen0.BYTES_PER_ELEMENT);
+  assertSame(0, aOverAbLen0.length);
+  assertSame(0, aOverAbLen0.byteLength);
+  assertSame(0, aOverAbLen0.byteOffset);
 }
 
 TestTypedArray(Uint8Array, 1, 0xFF);
 TestTypedArray(Int8Array, 1, -0x7F);
 TestTypedArray(Uint16Array, 2, 0xFFFF);
 TestTypedArray(Int16Array, 2, -0x7FFF);
 TestTypedArray(Uint32Array, 4, 0xFFFFFFFF);
 TestTypedArray(Int32Array, 4, -0x7FFFFFFF);
 TestTypedArray(Float32Array, 4, 0.5);
 TestTypedArray(Float64Array, 8, 0.5);
@@ skipping 53 matching lines @@
   }
   for (var i = 0; i < 20; i++) {
     TestProperty(m, i, 'val' + i);
     TestProperty(m, 'foo' + i, 'bar' + i);
   }
 }
 TestArbitrary(new ArrayBuffer(256));
 
 // Test direct constructor call
 assertTrue(ArrayBuffer() instanceof ArrayBuffer);