Added Prettifying Option to RewriteHistoryOptions see #621.

The default prettifying behabiour now is: do not prettify

Documentation for the new property of RewriteHistoryOptions

Author: Vogel612

LibGit2Sharp.Tests/FilterBranchFixture.cs

@@ -191,10 +191,10 @@ public void CanRewriteAuthorOfCommitsOnlyBeingPointedAtByTags()
             AssertSucceedingButNotError();
 
             var lightweightTag = repo.Tags["so-lonely"];
-            Assert.Equal("Bam!\n", ((Commit)lightweightTag.Target).Message);
+            Assert.Equal("Bam!", ((Commit)lightweightTag.Target).Message);
 
             var annotatedTag = repo.Tags["so-lonely-but-annotated"];
-            Assert.Equal("Bam!\n", ((Commit)annotatedTag.Target).Message);
+            Assert.Equal("Bam!", ((Commit)annotatedTag.Target).Message);
         }
 
         [Fact]
@@ -495,7 +495,7 @@ public void DoesNotRewriteRefsThatDontChange()
             var parents = repo.Branches["br2"].Tip.Parents.ToList();
             Assert.Equal(2, parents.Count());
             Assert.NotEmpty(parents.Where(c => c.Sha.StartsWith("9fd738e")));
-            Assert.Equal("abc\n", parents.Single(c => !c.Sha.StartsWith("9fd738e")).Message);
+            Assert.Equal("abc", parents.Single(c => !c.Sha.StartsWith("9fd738e")).Message);
         }
 
         [Fact]
@@ -530,7 +530,7 @@ public void CanNotOverWriteBackedUpReferences()
             AssertErrorFired(ex);
             AssertSucceedingNotFired();
 
-            Assert.Equal("abc\n", repo.Head.Tip.Message);
+            Assert.Equal("abc", repo.Head.Tip.Message);
 
             var newOriginalRefs = repo.Refs.FromGlob("refs/original/*").OrderBy(r => r.CanonicalName).ToArray();
             Assert.Equal(originalRefs, newOriginalRefs);
@@ -791,7 +791,7 @@ public void HandlesNameRewritingOfChainedTags()
             var newCommit = newAnnotationC.Target as Commit;
             Assert.NotNull(newCommit);
             Assert.NotEqual(newCommit, theCommit);
-            Assert.Equal("Rewrote\n", newCommit.Message);
+            Assert.Equal("Rewrote", newCommit.Message);
 
             // Ensure the original tag doesn't exist anymore
             Assert.Null(repo.Tags["lightweightA"]);

LibGit2Sharp/Core/HistoryRewriter.cs

@@ -52,7 +52,7 @@ public void Execute()
                 var commits = repo.Commits.QueryBy(filter);
                 foreach (var commit in commits)
                 {
-                    RewriteCommit(commit);
+                    RewriteCommit(commit, options);
                 }
 
                 // Ordering matters. In the case of `A -> B -> commit`, we need to make sure B is rewritten
@@ -199,7 +199,7 @@ private Reference RewriteReference<TRef, TTarget>(
             return refMap[oldRef] = movedRef;
         }
 
-        private void RewriteCommit(Commit commit)
+        private void RewriteCommit(Commit commit, RewriteHistoryOptions options)
         {
             var newHeader = CommitRewriteInfo.From(commit);
             var newTree = commit.Tree;
@@ -248,7 +248,7 @@ private void RewriteCommit(Commit commit)
                                                              newHeader.Message,
                                                              newTree,
                                                              mappedNewParents,
-                                                             true);
+                                                             options.PrettifyMessages);
 
             // Record the rewrite
             objectMap[commit] = newCommit;

LibGit2Sharp/RewriteHistoryOptions.cs

@@ -77,5 +77,13 @@ public RewriteHistoryOptions()
         /// </para>
         /// </summary>
         public Action<Exception> OnError { get; set; }
+
+        /// <summary>
+        /// Specifies Commit message prettifying behavior during rewrite.
+        /// NOTE: Prettifying may result in losing one or multiple lines in the commit message.
+        /// As such it is recommended to leave this set to false.
+        /// </summary>
+        /// <value><c>true</c> if Commit messages are prettified; otherwise, <c>false</c>.</value>
+        public bool PrettifyMessages { get; set; }
     }
 }