blame: Allow candidate to manage its setup before output

Pass in the RevWalk and let the candidate decide how to prepare itself
for output. This removes the conditional for the missing sourceCommit,
as candidates missing a commit can override the method with a no-op.

Change-Id: I3fa19b8676dfd3c177583f8f42593b5000b5350d

2 files changed, 12 insertions, 2 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/blame/BlameGenerator.java b/org.eclipse.jgit/src/org/eclipse/jgit/blame/BlameGenerator.java
index d90d59824d..dd6717b6dd 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/blame/BlameGenerator.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/blame/BlameGenerator.java
@@ -519,8 +519,7 @@ public class BlameGenerator {
 	}
 
 	private boolean result(Candidate n) throws IOException {
-		if (n.sourceCommit != null)
-			revPool.parseBody(n.sourceCommit);
+		n.beginResult(revPool);
 		outCandidate = n;
 		outRegion = n.regionList;
 		return true;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/blame/Candidate.java b/org.eclipse.jgit/src/org/eclipse/jgit/blame/Candidate.java
index a652278d05..c7c34f0a3a 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/blame/Candidate.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/blame/Candidate.java
@@ -49,6 +49,7 @@ import org.eclipse.jgit.blame.ReverseWalk.ReverseCommit;
 import org.eclipse.jgit.diff.Edit;
 import org.eclipse.jgit.diff.EditList;
 import org.eclipse.jgit.diff.RawText;
+import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectLoader;
@@ -56,6 +57,7 @@ import org.eclipse.jgit.lib.ObjectReader;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevFlag;
+import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.treewalk.filter.PathFilter;
 
 /**
@@ -114,6 +116,10 @@ class Candidate {
 		recursivePath = path.shouldBeRecursive();
 	}
 
+	void beginResult(RevWalk rw) throws MissingObjectException, IOException {
+		rw.parseBody(sourceCommit);
+	}
+
 	int getParentCount() {
 		return sourceCommit.getParentCount();
 	}
@@ -406,6 +412,11 @@ class Candidate {
 		}
 
 		@Override
+		void beginResult(RevWalk rw) {
+			// Blob candidates have nothing to prepare.
+		}
+
+		@Override
 		int getParentCount() {
 			return parent != null ? 1 : 0;
 		}