Adding comment to the fix of issue 95.

src/array.js

 // Copyright 2006-2008 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 654 matching lines @@
     x = ToString(x);
     y = ToString(y);
     if (x == y) return 0;
     else return x < y ? -1 : 1;
   };
 
   function QuickSort(a, from, to) {
     if (from >= to - 1) return;
     var pivot_index = $floor($random() * (to - from)) + from;
     var pivot = a[pivot_index];
+    // Issue 95: Keep the pivot element out of the comparisons to avoid
+    // infinite recursion if comparefn(pivot, pivot) != 0.
     a[pivot_index] = a[to - 1];
     a[to - 1] = pivot;
     var low_end = from;   // Upper bound of the elements lower than pivot.
     var high_start = to - 1; // Lower bound of the elements greater than pivot.
     for (var i = from; i < high_start; ) {
       var element = a[i];
       var order = Compare(element, pivot);
       if (order < 0) {
         a[i] = a[low_end];
         a[low_end] = element;
         low_end++;
         i++;
       } else if (order > 0) {
         high_start--;
         a[i] = a[high_start];
         a[high_start] = element;
       } else { // order == 0
         i++;
       }
     }
+    // Restore the pivot element to its rightful place.
     a[to - 1] = a[high_start];
     a[high_start] = pivot;
     high_start++;
     QuickSort(a, from, low_end);
     QuickSort(a, high_start, to);
   }
 
   var old_length = ToUint32(this.length);
 
   %RemoveArrayHoles(this);
@@ skipping 203 matching lines @@
     ArrayEvery: 1,
     ArrayMap: 1,
     ArrayIndexOf: 1,
     ArrayLastIndexOf: 1,
     ArrayPush: 1
   });
 };
 
 
 SetupArray();