1 files changed, 53 insertions, 34 deletions

diff --git a/mcs/class/corlib/System.Collections.Generic/List.cs b/mcs/class/corlib/System.Collections.Generic/List.cs
index 17056a1b21..840984f04f 100644
--- a/mcs/class/corlib/System.Collections.Generic/List.cs
+++ b/mcs/class/corlib/System.Collections.Generic/List.cs
@@ -69,7 +69,7 @@ namespace System.Collections.Generic {
 				AddEnumerable (collection);
 			} else {
 				_size = c.Count;
-				_items = new T [Math.Max (_size, DefaultCapacity)];
+				_items = new T [_size];
 				c.CopyTo (_items, 0);
 			}
 		}
@@ -116,6 +116,18 @@ namespace System.Collections.Generic {
 				throw new ArgumentException ("index and count exceed length of list");
 		}
 		
+		void CheckRangeOutOfRange (int idx, int count)
+		{
+			if (idx < 0)
+				throw new ArgumentOutOfRangeException ("index");
+			
+			if (count < 0)
+				throw new ArgumentOutOfRangeException ("count");
+
+			if ((uint) idx + (uint) count > (uint) _size)
+				throw new ArgumentOutOfRangeException ("index and count exceed length of list");
+		}
+
 		void AddCollection (ICollection <T> collection)
 		{
 			int collectionCount = collection.Count;
@@ -212,14 +224,27 @@ namespace System.Collections.Generic {
 		public bool Exists (Predicate <T> match)
 		{
 			CheckMatch(match);
-			return GetIndex(0, _size, match) != -1;
+
+			for (int i = 0; i < _size; i++) {
+				var item = _items [i];
+				if (match (item))
+					return true;
+			}
+
+			return false;
 		}
 		
 		public T Find (Predicate <T> match)
 		{
 			CheckMatch(match);
-			int i = GetIndex(0, _size, match);
-			return (i != -1) ? _items [i] : default (T);
+
+			for (int i = 0; i < _size; i++) {
+				var item = _items [i];
+				if (match (item))
+					return item;
+			}
+
+			return default (T);
 		}
 		
 		static void CheckMatch (Predicate <T> match)
@@ -296,68 +321,56 @@ namespace System.Collections.Generic {
 		public int FindIndex (Predicate <T> match)
 		{
 			CheckMatch (match);
-			return GetIndex (0, _size, match);
+			return Array.GetIndex (_items, 0, _size, match);
 		}
 		
 		public int FindIndex (int startIndex, Predicate <T> match)
 		{
 			CheckMatch (match);
-			CheckIndex (startIndex);
-			return GetIndex (startIndex, _size - startIndex, match);
+			CheckStartIndex (startIndex);
+			return Array.GetIndex (_items, startIndex, _size - startIndex, match);
 		}
 		public int FindIndex (int startIndex, int count, Predicate <T> match)
 		{
 			CheckMatch (match);
-			CheckRange (startIndex, count);
-			return GetIndex (startIndex, count, match);
-		}
-		int GetIndex (int startIndex, int count, Predicate <T> match)
-		{
-			int end = startIndex + count;
-			for (int i = startIndex; i < end; i ++)
-				if (match (_items [i]))
-					return i;
-				
-			return -1;
+			CheckRangeOutOfRange (startIndex, count);
+			return Array.GetIndex (_items, startIndex, count, match);
 		}
 		
 		public T FindLast (Predicate <T> match)
 		{
 			CheckMatch (match);
-			int i = GetLastIndex (0, _size, match);
+			int i = Array.GetLastIndex (_items, 0, _size, match);
 			return i == -1 ? default (T) : this [i];
 		}
 		
 		public int FindLastIndex (Predicate <T> match)
 		{
 			CheckMatch (match);
-			return GetLastIndex (0, _size, match);
+			return Array.GetLastIndex (_items, 0, _size, match);
 		}
 		
 		public int FindLastIndex (int startIndex, Predicate <T> match)
 		{
 			CheckMatch (match);
-			CheckIndex (startIndex);
-			return GetLastIndex (0, startIndex + 1, match);
+			CheckStartIndex (startIndex);
+			return Array.GetLastIndex (_items, 0, startIndex + 1, match);
 		}
 		
 		public int FindLastIndex (int startIndex, int count, Predicate <T> match)
 		{
 			CheckMatch (match);
-			int start = startIndex - count + 1;
-			CheckRange (start, count);
-			return GetLastIndex (start, count, match);
-		}
+			CheckStartIndex (startIndex);
+			
+			if (count < 0)
+				throw new ArgumentOutOfRangeException ("count");
 
-		int GetLastIndex (int startIndex, int count, Predicate <T> match)
-		{
-			// unlike FindLastIndex, takes regular params for search range
-			for (int i = startIndex + count; i != startIndex;)
-				if (match (_items [--i]))
-					return i;
-			return -1;	
+			if (startIndex - count + 1 < 0)
+				throw new ArgumentOutOfRangeException ("count must refer to a location within the collection");
+
+			return Array.GetLastIndex (_items, startIndex - count + 1, count, match);
 		}
-		
+
 		public void ForEach (Action <T> action)
 		{
 			if (action == null)
@@ -423,6 +436,12 @@ namespace System.Collections.Generic {
 			if (index < 0 || (uint) index > (uint) _size)
 				throw new ArgumentOutOfRangeException ("index");
 		}
+
+		void CheckStartIndex (int index)
+		{
+			if (index < 0 || (uint) index > (uint) _size)
+				throw new ArgumentOutOfRangeException ("startIndex");
+		}
 		
 		public void Insert (int index, T item)
 		{