[Mono-bugs] [Bug 76921][Min] New - Enum.FormatFlags fails to properly handle the "No bits set" case

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Changed by peter at novonyx.com.

http://bugzilla.ximian.com/show_bug.cgi?id=76921

--- shadow/76921	2005-12-05 15:24:49.000000000 -0500
+++ shadow/76921.tmp.28559	2005-12-05 15:24:49.000000000 -0500
@@ -0,0 +1,51 @@
+Bug#: 76921
+Product: Mono: Class Libraries
+Version: 1.1
+OS: All
+OS Details: 
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Minor
+Component: CORLIB
+AssignedTo: mono-bugs at ximian.com                            
+ReportedBy: peter at novonyx.com               
+QAContact: mono-bugs at ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: Enum.FormatFlags fails to properly handle the "No bits set" case
+
+Running the code below, you would expect to get
+  None
+  One
+as the result, like on MS.Net. However, Mono returns
+  None,
+  None, one
+instead, since Enum.cs sorts the enum values by numbers and subsequently 
+assumes that the "No bits set" value (0) is at position 0. However,  
+the "Negative" enum item causes that assumption to fail.
+
+I've attached a patch. I removed the assumption from all types (not just 
+the signed ones) for consistency.
+
+using System;
+
+public class FlagsTest {
+        [Flags]
+        enum TestEnum {
+                None = 0,
+                One = 1,
+                Two = 2,
+                Negative = unchecked((int)0xFFFF0000)
+        }
+
+        static void Main() {
+                TestEnum t;
+
+                t = TestEnum.None;
+                Console.WriteLine("Enum: {0}", t);
+                t = TestEnum.One;
+                Console.WriteLine("Enum: {0}", t);
+        }
+}