Fix for objectAtIndex: throwing out of range exceptions.

Closes #105.

Reviewed by me.

Foundation/CPArray.j

@@ -26,6 +26,7 @@
 @import "CPSortDescriptor.j"
 @import "CPException.j"
 
+
 /* @ignore */
 @implementation _CPArrayEnumerator : CPEnumerator
 {
@@ -520,6 +521,9 @@
 */
 - (id)objectAtIndex:(int)anIndex
 {
+    if (anIndex >= length)
+        [CPException raise:CPRangeException reason:@"index (" + anIndex + @") beyond bounds (" + length + @")"];
+
     return self[anIndex];
 }
 

Tests/Foundation/CPArrayTest.j

@@ -115,6 +115,46 @@
           equals:2];
 }
 
+- (void)testIndexOutOfBounds
+{
+    try
+    {
+        [[] objectAtIndex:0];
+        [self assert:false];
+    }
+    catch (anException)
+    {
+        [self assert:[anException name] equals:CPRangeException];
+        [self assert:[anException reason] equals:@"index (0) beyond bounds (0)"];
+    }
+
+    [[0, 1, 2] objectAtIndex:0];
+    [[0, 1, 2] objectAtIndex:1];
+    [[0, 1, 2] objectAtIndex:2];
+
+    try
+    {
+        [[0, 1, 2] objectAtIndex:3];
+        [self assert:false];
+    }
+    catch (anException)
+    {
+        [self assert:[anException name] equals:CPRangeException];
+        [self assert:[anException reason] equals:@"index (3) beyond bounds (3)"];
+    }
+
+    try
+    {
+        [[0, 1, 2] objectAtIndex:4];
+        [self assert:false];
+    }
+    catch (anException)
+    {
+        [self assert:[anException name] equals:CPRangeException];
+        [self assert:[anException reason] equals:@"index (4) beyond bounds (3)"];
+    }
+}
+
 @end
 
 @implementation CPArray (reverse)