1 files changed, 57 insertions, 17 deletions

diff --git a/mcs/class/corlib/System/Array.cs b/mcs/class/corlib/System/Array.cs
index 91654019f1..756378c56d 100644
--- a/mcs/class/corlib/System/Array.cs
+++ b/mcs/class/corlib/System/Array.cs
@@ -2864,32 +2864,54 @@ namespace System
 		{
 			if (array == null)
 				throw new ArgumentNullException ("array");
+
+			if (match == null)
+				throw new ArgumentNullException ("match");
 			
-			return FindLastIndex<T> (array, 0, array.Length, match);
+			return GetLastIndex (array, 0, array.Length, match);
 		}
 		
 		public static int FindLastIndex<T> (T [] array, int startIndex, Predicate<T> match)
 		{
 			if (array == null)
 				throw new ArgumentNullException ();
+
+			if (startIndex < 0 || (uint) startIndex > (uint) array.Length)
+				throw new ArgumentOutOfRangeException ("startIndex");
+
+			if (match == null)
+				throw new ArgumentNullException ("match");
 			
-			return FindLastIndex<T> (array, startIndex, array.Length - startIndex, match);
+			return GetLastIndex (array, 0, startIndex + 1, match);
 		}
 		
 		public static int FindLastIndex<T> (T [] array, int startIndex, int count, Predicate<T> match)
 		{
 			if (array == null)
 				throw new ArgumentNullException ("array");
+
 			if (match == null)
 				throw new ArgumentNullException ("match");
+
+			if (startIndex < 0 || (uint) startIndex > (uint) array.Length)
+				throw new ArgumentOutOfRangeException ("startIndex");
 			
-			if (startIndex > array.Length || startIndex + count > array.Length)
-				throw new ArgumentOutOfRangeException ();
-			
-			for (int i = startIndex + count - 1; i >= startIndex; i--)
-				if (match (array [i]))
+			if (count < 0)
+				throw new ArgumentOutOfRangeException ("count");
+
+			if (startIndex - count + 1 < 0)
+				throw new ArgumentOutOfRangeException ("count must refer to a location within the array");
+
+			return GetLastIndex (array, startIndex - count + 1, count, match);
+		}
+
+		internal static int GetLastIndex<T> (T[] array, int startIndex, int count, Predicate<T> match)
+		{
+			// unlike FindLastIndex, takes regular params for search range
+			for (int i = startIndex + count; i != startIndex;)
+				if (match (array [--i]))
 					return i;
-				
+
 			return -1;
 		}
 		
@@ -2897,16 +2919,25 @@ namespace System
 		{
 			if (array == null)
 				throw new ArgumentNullException ("array");
+
+			if (match == null)
+				throw new ArgumentNullException ("match");
 			
-			return FindIndex<T> (array, 0, array.Length, match);
+			return GetIndex (array, 0, array.Length, match);
 		}
 		
 		public static int FindIndex<T> (T [] array, int startIndex, Predicate<T> match)
 		{
 			if (array == null)
 				throw new ArgumentNullException ("array");
-			
-			return FindIndex<T> (array, startIndex, array.Length - startIndex, match);
+
+			if (startIndex < 0 || (uint) startIndex > (uint) array.Length)
+				throw new ArgumentOutOfRangeException ("startIndex");
+
+			if (match == null)
+				throw new ArgumentNullException ("match");
+
+			return GetIndex (array, startIndex, array.Length - startIndex, match);
 		}
 		
 		public static int FindIndex<T> (T [] array, int startIndex, int count, Predicate<T> match)
@@ -2914,13 +2945,22 @@ namespace System
 			if (array == null)
 				throw new ArgumentNullException ("array");
 			
-			if (match == null)
-				throw new ArgumentNullException ("match");
+			if (startIndex < 0)
+				throw new ArgumentOutOfRangeException ("startIndex");
 			
-			if (startIndex > array.Length || startIndex + count > array.Length)
-				throw new ArgumentOutOfRangeException ();
-			
-			for (int i = startIndex; i < startIndex + count; i ++)
+			if (count < 0)
+				throw new ArgumentOutOfRangeException ("count");
+
+			if ((uint) startIndex + (uint) count > (uint) array.Length)
+				throw new ArgumentOutOfRangeException ("index and count exceed length of list");
+
+			return GetIndex (array, startIndex, count, match);
+		}
+
+		internal static int GetIndex<T> (T[] array, int startIndex, int count, Predicate<T> match)
+		{
+			int end = startIndex + count;
+			for (int i = startIndex; i < end; i ++)
 				if (match (array [i]))
 					return i;