Make IsMissing more generic

LibGit2Sharp.sln.DotSettings

@@ -11,6 +11,9 @@
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/SPACE_WITHING_EMPTY_BRACES/@EntryValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/SPACE_WITHIN_SINGLE_LINE_ARRAY_INITIALIZER_BRACES/@EntryValue">True</s:Boolean>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=PrivateInstanceFields/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="aaBb" /&gt;</s:String>
+	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpKeepExistingMigration/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpPlaceEmbeddedOnSameLineMigration/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpUseContinuousIndentInsideBracesMigration/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EAddAccessorOwnerDeclarationBracesMigration/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EMigrateBlankLinesAroundFieldToBlankLinesAroundProperty/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EMigrateThisQualifierSettings/@EntryIndexedValue">True</s:Boolean>

LibGit2Sharp/Blob.cs

@@ -15,7 +15,6 @@ public class Blob : GitObject
     {
         private readonly ILazy<Int64> lazySize;
         private readonly ILazy<bool> lazyIsBinary;
-        private readonly ILazy<bool> lazyIsMissing;
 
         /// <summary>
         /// Needed for mocking purposes.s
@@ -26,9 +25,8 @@ protected Blob()
         internal Blob(Repository repo, ObjectId id)
             : base(repo, id)
         {
-            lazySize = GitObjectLazyGroup.Singleton(repo, id, Proxy.git_blob_rawsize);
-            lazyIsBinary = GitObjectLazyGroup.Singleton(repo, id, Proxy.git_blob_is_binary);
-            lazyIsMissing = GitObjectLazyGroup.Singleton(repo, id, handle => handle == null, throwsIfMissing: false);
+            lazySize = GitObjectLazyGroup.Singleton(repo, id, Proxy.git_blob_rawsize, throwIfMissing: true);
+            lazyIsBinary = GitObjectLazyGroup.Singleton(repo, id, Proxy.git_blob_is_binary, throwIfMissing: true);
         }
 
         /// <summary>
@@ -47,12 +45,6 @@ internal Blob(Repository repo, ObjectId id)
         /// <exception cref="NotFoundException">Throws if blob is missing</exception>
         public virtual bool IsBinary => lazyIsBinary.Value;
 
-
-        /// <summary>
-        ///  Determine if the blob content is missing ( with partially cloned repositories)
-        /// </summary>
-        public virtual bool IsMissing => lazyIsMissing.Value;
-
         /// <summary>
         /// Gets the blob content in a <see cref="Stream"/>.
         /// </summary>

LibGit2Sharp/Core/GitObjectLazyGroup.cs

@@ -17,22 +17,16 @@ protected override void EvaluateInternal(Action<ObjectHandle> evaluator)
         {
             using (var osw = new ObjectSafeWrapper(id, repo.Handle))
             {
-                if (osw.ObjectPtr == null)
-                    throw new NotFoundException($"No valid git object identified by '{id}' exists in the repository.");
-
                 evaluator(osw.ObjectPtr);
             }
         }
 
-        public static ILazy<TResult> Singleton<TResult>(Repository repo, ObjectId id, Func<ObjectHandle, TResult> resultSelector, bool throwsIfMissing = true)
+        public static ILazy<TResult> Singleton<TResult>(Repository repo, ObjectId id, Func<ObjectHandle, TResult> resultSelector, bool throwIfMissing = false)
         {
             return Singleton(() =>
             {
-                using (var osw = new ObjectSafeWrapper(id, repo.Handle))
+                using (var osw = new ObjectSafeWrapper(id, repo.Handle, throwIfMissing: throwIfMissing))
                 {
-                    if (throwsIfMissing && osw.ObjectPtr == null)
-                        throw new NotFoundException($"No valid git object identified by '{id}' exists in the repository.");
-
                     return resultSelector(osw.ObjectPtr);
                 }
             });

LibGit2Sharp/Core/ObjectSafeWrapper.cs

@@ -7,7 +7,7 @@ internal class ObjectSafeWrapper : IDisposable
     {
         private readonly ObjectHandle objectPtr;
 
-        public unsafe ObjectSafeWrapper(ObjectId id, RepositoryHandle handle, bool allowNullObjectId = false)
+        public unsafe ObjectSafeWrapper(ObjectId id, RepositoryHandle handle, bool allowNullObjectId = false, bool throwIfMissing = false)
         {
             Ensure.ArgumentNotNull(handle, "handle");
 
@@ -20,13 +20,15 @@ public unsafe ObjectSafeWrapper(ObjectId id, RepositoryHandle handle, bool allow
                 Ensure.ArgumentNotNull(id, "id");
                 objectPtr = Proxy.git_object_lookup(handle, id, GitObjectType.Any);
             }
-        }
 
-        public ObjectHandle ObjectPtr
-        {
-            get { return objectPtr; }
+            if (objectPtr == null && throwIfMissing)
+            {
+                throw new NotFoundException($"No valid git object identified by '{id}' exists in the repository.");
+            }
         }
 
+        public ObjectHandle ObjectPtr => objectPtr;
+
         public void Dispose()
         {
             Dispose(true);

LibGit2Sharp/GitObject.cs

@@ -1,9 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.Globalization;
 using LibGit2Sharp.Core;
-using LibGit2Sharp.Core.Handles;
 
 namespace LibGit2Sharp
 {
@@ -33,6 +31,8 @@ public abstract class GitObject : IEquatable<GitObject>, IBelongToARepository
         private static readonly LambdaEqualityHelper<GitObject> equalityHelper =
             new LambdaEqualityHelper<GitObject>(x => x.Id);
 
+        private readonly ILazy<bool> lazyIsMissing;
+
         /// <summary>
         /// The <see cref="Repository"/> containing the object.
         /// </summary>
@@ -53,13 +53,22 @@ protected GitObject(Repository repo, ObjectId id)
         {
             this.repo = repo;
             Id = id;
+            lazyIsMissing = GitObjectLazyGroup.Singleton(repo, id, handle => handle == null, throwIfMissing: false);
         }
 
         /// <summary>
         /// Gets the id of this object
         /// </summary>
         public virtual ObjectId Id { get; private set; }
 
+        /// <summary>
+        ///  Determine if the object is missing
+        /// </summary>
+        /// <remarks>
+        /// This is common when dealing with partially cloned repositories as blobs or trees could be missing
+        /// </remarks>
+        public virtual bool IsMissing => lazyIsMissing.Value;
+
         /// <summary>
         /// Gets the 40 character sha1 of this object.
         /// </summary>

LibGit2Sharp/Tree.cs

@@ -31,13 +31,13 @@ internal Tree(Repository repo, ObjectId id, string path)
         {
             this.path = path ?? "";
 
-            lazyCount = GitObjectLazyGroup.Singleton(repo, id, Proxy.git_tree_entrycount);
+            lazyCount = GitObjectLazyGroup.Singleton(repo, id, Proxy.git_tree_entrycount, throwIfMissing: true);
         }
 
         /// <summary>
         /// Gets the number of <see cref="TreeEntry"/> immediately under this <see cref="Tree"/>.
         /// </summary>
-        public virtual int Count { get { return lazyCount.Value; } }
+        public virtual int Count => lazyCount.Value;
 
         /// <summary>
         /// Gets the <see cref="TreeEntry"/> pointed at by the <paramref name="relativePath"/> in this <see cref="Tree"/> instance.