Fix diff header on renamed or copied files

When git-core renames or copies a file and the mode differs the
header shows the mode change first, then the rename or copy data:

  diff --git a/COPYING b/LICENSE
  old mode 100644
  new mode 100755
  similarity index 92%
  rename from COPYING
  rename to LICENSE
  index d645695..54863be
  --- a/COPYING
  +++ b/LICENSE
  @@ -56,20 +56,6 @@

JGit relies on this ordering inside of FileHeader. Parsing "new file
mode NNN" after "copy from/to" or "rename from/to" resets the change
type to be ADD, losing the COPIED or RENAMED status and old path.

This fixes a 4 year old bug in Gerrit Code Review that prevents
opening a file for review if the file was copied from another file,
modified in this change, and the mode was updated (e.g. execute
bit was added).

Change-Id: If4c9ecd61ef0ca8e3e1ea857301f7b5c948efb96
[ms: added test case]
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/diff/DiffFormatterTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/diff/DiffFormatterTest.java
index 00e5f06747..145d899028 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/diff/DiffFormatterTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/diff/DiffFormatterTest.java
@@ -286,6 +286,29 @@ public class DiffFormatterTest extends RepositoryTestCase {
 	}
 
 	@Test
+	public void testCreateFileHeaderForRenameModeChange()
+			throws Exception {
+		DiffEntry a = DiffEntry.delete(PATH_A, ObjectId.zeroId());
+		DiffEntry b = DiffEntry.add(PATH_B, ObjectId.zeroId());
+		b.oldMode = FileMode.REGULAR_FILE;
+		b.newMode = FileMode.EXECUTABLE_FILE;
+		DiffEntry m = DiffEntry.pair(ChangeType.RENAME, a, b, 100);
+		m.oldId = null;
+		m.newId = null;
+
+		FileHeader fh = df.toFileHeader(m);
+		//@formatter:off
+		String expected = DIFF + "a/src/a b/src/b\n" +
+				"old mode 100644\n" +
+				"new mode 100755\n" +
+				"similarity index 100%\n" +
+				"rename from src/a\n" +
+				"rename to src/b\n";
+		//@formatter:on
+		assertEquals(expected, fh.getScriptText());
+	}
+
+	@Test
 	public void testDiff() throws Exception {
 		write(new File(db.getDirectory().getParent(), "test.txt"), "test");
 		File folder = new File(db.getDirectory().getParent(), "folder");