Fix bad checkout behaviour when a file is removed

We deleted the entry if there was a file and an index
entry, but not when there was just an index entry. Now
delete the file in both cases since the missing file
just means our worktree is dirty. This affected the
implementation of reset --hard.

Bug: 347574
Change-Id: Ie66fa61303472422830f5e33614e93ad65094e5d

org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/DirCacheCheckoutTest.java

@@ -47,6 +47,7 @@ import java.util.Map;
 
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.api.MergeResult.MergeStatus;
+import org.eclipse.jgit.api.ResetCommand.ResetType;
 import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.api.errors.NoFilepatternException;
 import org.eclipse.jgit.dircache.DirCache;
@@ -147,6 +148,35 @@ public class DirCacheCheckoutTest extends ReadTreeTest {
 				"h()", "untracked", "untracked"));
 	}
 
+	/**
+	 * Reset hard from unclean condition.
+	 * <p>
+	 * WorkDir: Empty <br/>
+	 * Index: f/g <br/>
+	 * Merge: x
+	 *
+	 * @throws Exception
+	 */
+	@Test
+	public void testResetHardFromIndexEntryWithoutFileToTreeWithoutFile()
+			throws Exception {
+		Git git = new Git(db);
+		writeTrashFile("x", "x");
+		git.add().addFilepattern("x").call();
+		RevCommit id1 = git.commit().setMessage("c1").call();
+
+		writeTrashFile("f/g", "f/g");
+		git.rm().addFilepattern("x").call();
+		git.add().addFilepattern("f/g").call();
+		git.commit().setMessage("c2").call();
+		deleteTrashFile("f/g");
+		deleteTrashFile("f");
+
+		// The actual test
+		git.reset().setMode(ResetType.HARD).setRef(id1.getName()).call();
+		assertIndex(mkmap("x", "x"));
+	}
+
 	private DirCacheCheckout resetHard(RevCommit commit)
 			throws NoWorkTreeException,
 			CorruptObjectException, IOException {

org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java

@@ -352,12 +352,10 @@ public class DirCacheCheckout {
 					}
 				}
 			} else {
-				// There is no file/folder for that path in the working tree.
-				// The only entry we have is the index entry. If that entry is a
-				// conflict simply remove it. Otherwise keep that entry in the
-				// index
-				if (i.getDirCacheEntry().getStage() == 0)
-					keep(i.getDirCacheEntry());
+				// There is no file/folder for that path in the working tree,
+				// nor in the merge head.
+				// The only entry we have is the index entry. Like the case
+				// where there is a file with the same name, remove it,
 			}
 		}
 	}