repo command: properly name the required 'path' argument

Fixes point 4 in bug 484951, where "jgit repo" or "jgit repo -h" dumps a
stack trace.

Bug: 484951
Change-Id: Ic8b362e07a40ad923dc9acde0c0983a1e7932a02
Signed-off-by: Andrey Loskutov <loskutov@gmx.de>

org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/RepoTest.java

@@ -42,10 +42,13 @@
  */
 package org.eclipse.jgit.pgm;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 import java.io.File;
+import java.util.Arrays;
+
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.junit.JGitTestUtil;
 import org.eclipse.jgit.lib.CLIRepositoryTestCase;
@@ -97,6 +100,27 @@ public class RepoTest extends CLIRepositoryTestCase {
 		resolveRelativeUris();
 	}
 
+	@Test
+	public void testMissingPath() throws Exception {
+		assertEquals("fatal: Argument \"path\" is required",
+				execute("git repo")[0]);
+	}
+
+	/**
+	 * See bug 484951: "git repo -h" should not print unexpected values
+	 *
+	 * @throws Exception
+	 */
+	@Test
+	public void testZombieHelpArgument() throws Exception {
+		String[] output = execute("git repo -h");
+		String all = Arrays.toString(output);
+		assertTrue("Unexpected help output: " + all,
+				all.contains("jgit repo"));
+		assertFalse("Unexpected help output: " + all,
+				all.contains("jgit repo VAL"));
+	}
+
 	@Test
 	public void testAddRepoManifest() throws Exception {
 		StringBuilder xmlContent = new StringBuilder();

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Repo.java

@@ -55,7 +55,7 @@ class Repo extends TextBuiltin {
 	@Option(name = "--groups", aliases = { "-g" }, usage = "usage_groups")
 	private String groups = "default"; //$NON-NLS-1$
 
-	@Argument(required = true, usage = "usage_pathToXml")
+	@Argument(required = true, metaVar = "metaVar_path", usage = "usage_pathToXml")
 	private String path;
 
 	@Option(name = "--record-remote-branch", usage = "usage_branches")