Fix array index normalize in case index is negative zero

JerryScript-DCO-1.0-Signed-off-by: Dániel Bátyai dbatyai.u-szeged@partner.samsung.com

jerry-core/ecma/builtin-objects/ecma-builtin-helpers.cpp

@@ -298,7 +298,11 @@ ecma_builtin_helper_array_index_normalize (ecma_number_t index, /**< index */
   if (!ecma_number_is_nan (index))
   {
 
-    if (ecma_number_is_infinity (index))
+    if (ecma_number_is_zero (index))
+    {
+      norm_index = 0;
+    }
+    else if (ecma_number_is_infinity (index))
     {
       norm_index = ecma_number_is_negative (index) ? 0 : length;
     }

tests/jerry/array-prototype-indexof.js

@@ -37,6 +37,8 @@ assert(array.indexOf("foo", NaN) === 0);
 assert(array.indexOf("foo", Infinity) === -1);
 assert(array.indexOf("foo", -Infinity) === 0);
 
+assert([true].indexOf(true, -0) === 0);
+
 // Checking behavior when length is zero
 var obj = { indexOf : Array.prototype.indexOf, length : 0 };
 assert(obj.indexOf("foo") === -1);