Revert "Remove handle when dispose is called for the first time"

This reverts commit 05d23bb.

Author: jbialobr

LibGit2Sharp/Core/Handles/ConfigurationSafeHandle.cs

@@ -2,7 +2,7 @@
 {
     internal class ConfigurationSafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_config_free(handle);
             return true;

LibGit2Sharp/Core/Handles/DiffListSafeHandle.cs

@@ -2,7 +2,7 @@ namespace LibGit2Sharp.Core.Handles
 {
     internal class DiffListSafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_diff_list_free(handle);
             return true;

LibGit2Sharp/Core/Handles/GitObjectSafeHandle.cs

@@ -2,7 +2,7 @@
 {
     internal class GitObjectSafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_object_free(handle);
             return true;

LibGit2Sharp/Core/Handles/IndexSafeHandle.cs

@@ -2,7 +2,7 @@
 {
     internal class IndexSafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_index_free(handle);
             return true;

LibGit2Sharp/Core/Handles/NoteSafeHandle.cs

@@ -2,7 +2,7 @@
 {
     internal class NoteSafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_note_free(handle);
             return true;

LibGit2Sharp/Core/Handles/NullGitObjectSafeHandle.cs

@@ -9,7 +9,7 @@ public NullGitObjectSafeHandle()
             handle = IntPtr.Zero;
         }
 
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             // Nothing to release
             return true;

LibGit2Sharp/Core/Handles/NullIndexSafeHandle.cs

@@ -9,7 +9,7 @@ public NullIndexSafeHandle()
             handle = IntPtr.Zero;
         }
 
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             // Nothing to release
             return true;

LibGit2Sharp/Core/Handles/ObjectDatabaseSafeHandle.cs

@@ -2,7 +2,7 @@
 {
     internal class ObjectDatabaseSafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_odb_free(handle);
             return true;

LibGit2Sharp/Core/Handles/PushSafeHandle.cs

@@ -2,7 +2,7 @@
 {
     internal class PushSafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_push_free(handle);
             return true;

LibGit2Sharp/Core/Handles/ReferenceSafeHandle.cs

@@ -2,7 +2,7 @@
 {
     internal class ReferenceSafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_reference_free(handle);
             return true;

LibGit2Sharp/Core/Handles/RemoteSafeHandle.cs

@@ -2,7 +2,7 @@
 {
     internal class RemoteSafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_remote_free(handle);
             return true;

LibGit2Sharp/Core/Handles/RepositorySafeHandle.cs

@@ -2,7 +2,7 @@
 {
     internal class RepositorySafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_repository_free(handle);
             return true;

LibGit2Sharp/Core/Handles/RevWalkerSafeHandle.cs

@@ -2,7 +2,7 @@
 {
     internal class RevWalkerSafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_revwalk_free(handle);
             return true;

LibGit2Sharp/Core/Handles/SafeHandleBase.cs

@@ -2,7 +2,6 @@
 using System.Diagnostics;
 using System.Globalization;
 using System.Runtime.InteropServices;
-using System.Threading;
 
 namespace LibGit2Sharp.Core.Handles
 {
@@ -12,8 +11,6 @@ internal abstract class SafeHandleBase : SafeHandle
         private readonly string trace;
 #endif
 
-        private int disposeCount = 0;
-
         protected SafeHandleBase()
             : base(IntPtr.Zero, true)
         {
@@ -23,9 +20,9 @@ protected SafeHandleBase()
 #endif
         }
 
+#if DEBUG
         protected override void Dispose(bool disposing)
         {
-#if DEBUG
             if (!disposing && !IsInvalid)
             {
                 Trace.WriteLine(string.Format(CultureInfo.InvariantCulture, "A {0} handle wrapper has not been properly disposed.", GetType().Name));
@@ -34,18 +31,28 @@ protected override void Dispose(bool disposing)
 #endif
                 Trace.WriteLine("");
             }
-#endif
-            base.Dispose(disposing);
 
-            if (Interlocked.Increment(ref disposeCount) == 1)
-                NativeMethods.RemoveHandle();
+            base.Dispose(disposing);
         }
+#endif
 
         public override bool IsInvalid
         {
             get { return (handle == IntPtr.Zero); }
         }
 
-        protected abstract override bool ReleaseHandle();
+        protected abstract bool ReleaseHandleImpl();
+
+        protected override sealed bool ReleaseHandle()
+        {
+            try
+            {
+                return ReleaseHandleImpl();
+            }
+            finally
+            {
+                NativeMethods.RemoveHandle();
+            }
+        }
     }
 }

LibGit2Sharp/Core/Handles/SignatureSafeHandle.cs

@@ -2,7 +2,7 @@
 {
     internal class SignatureSafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_signature_free(handle);
             return true;

LibGit2Sharp/Core/Handles/TreeBuilderSafeHandle.cs

@@ -2,7 +2,7 @@ namespace LibGit2Sharp.Core.Handles
 {
     internal class TreeBuilderSafeHandle : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_treebuilder_free(handle);
             return true;

LibGit2Sharp/Core/Handles/TreeEntrySafeHandle_Owned.cs

@@ -2,7 +2,7 @@
 {
     internal class TreeEntrySafeHandle_Owned : SafeHandleBase
     {
-        protected override bool ReleaseHandle()
+        protected override bool ReleaseHandleImpl()
         {
             Proxy.git_tree_entry_free(handle);
             return true;