Prevent from NullPointerException's

Prevent from NPE when argument of GitResourceVariantTree.members()
doesn't exist in repository.

Change-Id: Iedfd286721e5a5add3ddf96b0ee83e70aa327631
Signed-off-by: Dariusz Luksza <dariusz@luksza.org>

2 files changed, 24 insertions, 8 deletions

diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/synchronize/GitResourceVariantTree.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/synchronize/GitResourceVariantTree.java
index 3eec66b762..240f828ef0 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/synchronize/GitResourceVariantTree.java
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/synchronize/GitResourceVariantTree.java
@@ -164,9 +164,11 @@ abstract class GitResourceVariantTree extends AbstractResourceVariantTree {
 			Tree tree = getRevTree(resource);
 			ObjectId objId = getRevObjId(resource);
 
-			trees.put(db, tree);
-			// walk the tree to retrieve information
-			walk(db, objId, tree);
+			if (objId != null && tree != null) {
+				trees.put(db, tree);
+				// walk the tree to retrieve information
+				walk(db, objId, tree);
+			}
 		}
 	}
 
@@ -387,6 +389,10 @@ abstract class GitResourceVariantTree extends AbstractResourceVariantTree {
 		Repository repo = gsd.getRepository();
 		try {
 			Tree tree = gsd.mapSrcTree();
+
+			if (tree == null)
+				return new IResource[0];
+
 			IResource[] members = ((IContainer) resource).members();
 			Set<IResource> membersSet = getAllMembers(repo, tree, members);
 
diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/synchronize/dto/GitSynchronizeData.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/synchronize/dto/GitSynchronizeData.java
index 4f66e4ed13..b29f5096ba 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/synchronize/dto/GitSynchronizeData.java
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/synchronize/dto/GitSynchronizeData.java
@@ -160,17 +160,27 @@ public class GitSynchronizeData {
 	private Tree mapTree(String rev) throws IOException {
 		if (rev.startsWith(Constants.R_TAGS)) {
 			Tag tag = repo.mapTag(rev);
-			Commit commit = repo.mapCommit(tag.getObjId());
-			return commit.getTree();
+			if (tag != null) {
+				Commit commit = repo.mapCommit(tag.getObjId());
+				if (commit != null)
+					return commit.getTree();
+			}
+			return null;
 		} else
 			return repo.mapTree(rev);
 	}
 
 	private ObjectId getObjecId(String rev) throws IOException {
 		if (rev.startsWith(Constants.R_TAGS)) {
-			return repo.mapTag(rev).getObjId();
-		} else
-			return repo.mapCommit(rev).getCommitId();
+			Tag mapTag = repo.mapTag(rev);
+			if (mapTag != null)
+				return mapTag.getObjId();
+		} else {
+			Commit mapCommit = repo.mapCommit(rev);
+			if (mapCommit != null)
+				return mapCommit.getCommitId();
+		}
+		return null;
 	}
 
 }