Enhance test coverage when core.filemode is false

Some branches in WorkingTreeIterator.getIndexFileMode() have not been
covered by tests. Enhance the tests to increase test coverage.

Change-Id: I400a221048f0f6cbaa987350eaf998b0ebb50a4e

org.eclipse.jgit.test/tst/org/eclipse/jgit/api/AddCommandTest.java

@@ -45,7 +45,6 @@ package org.eclipse.jgit.api;
 
 import static org.eclipse.jgit.util.FileUtils.RECURSIVE;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
@@ -955,7 +954,11 @@ public class AddCommandTest extends RepositoryTestCase {
 			}
 
 			public boolean canExecute(File f) {
-				return true;
+				try {
+					return read(f).startsWith("binary:");
+				} catch (IOException e) {
+					return false;
+				}
 			}
 
 			@Override
@@ -966,61 +969,40 @@ public class AddCommandTest extends RepositoryTestCase {
 
 		Git git = Git.open(db.getDirectory(), executableFs);
 		String path = "a.txt";
+		String path2 = "a.sh";
 		writeTrashFile(path, "content");
-		git.add().addFilepattern(path).call();
+		writeTrashFile(path2, "binary: content");
+		git.add().addFilepattern(path).addFilepattern(path2).call();
 		RevCommit commit1 = git.commit().setMessage("commit").call();
-		TreeWalk walk = TreeWalk.forPath(db, path, commit1.getTree());
-		assertNotNull(walk);
-		assertEquals(FileMode.EXECUTABLE_FILE, walk.getFileMode(0));
-
-		FS nonExecutableFs = new FS() {
-
-			public boolean supportsExecute() {
-				return false;
-			}
-
-			public boolean setExecute(File f, boolean canExec) {
-				return false;
-			}
-
-			public ProcessBuilder runInShell(String cmd, String[] args) {
-				return null;
-			}
-
-			public boolean retryFailedLockFileCommit() {
-				return false;
-			}
-
-			public FS newInstance() {
-				return this;
-			}
-
-			protected File discoverGitExe() {
-				return null;
-			}
-
-			public boolean canExecute(File f) {
-				return false;
-			}
-
-			@Override
-			public boolean isCaseSensitive() {
-				return false;
-			}
-		};
+		try (TreeWalk walk = new TreeWalk(db)) {
+			walk.addTree(commit1.getTree());
+			walk.next();
+			assertEquals(path2, walk.getPathString());
+			assertEquals(FileMode.EXECUTABLE_FILE, walk.getFileMode(0));
+			walk.next();
+			assertEquals(path, walk.getPathString());
+			assertEquals(FileMode.REGULAR_FILE, walk.getFileMode(0));
+		}
 
 		config = db.getConfig();
 		config.setBoolean(ConfigConstants.CONFIG_CORE_SECTION, null,
 				ConfigConstants.CONFIG_KEY_FILEMODE, false);
 		config.save();
 
-		Git git2 = Git.open(db.getDirectory(), nonExecutableFs);
-		writeTrashFile(path, "content2");
-		git2.add().addFilepattern(path).call();
+		Git git2 = Git.open(db.getDirectory(), executableFs);
+		writeTrashFile(path2, "content2");
+		writeTrashFile(path, "binary: content2");
+		git2.add().addFilepattern(path).addFilepattern(path2).call();
 		RevCommit commit2 = git2.commit().setMessage("commit2").call();
-		walk = TreeWalk.forPath(db, path, commit2.getTree());
-		assertNotNull(walk);
-		assertEquals(FileMode.EXECUTABLE_FILE, walk.getFileMode(0));
+		try (TreeWalk walk = new TreeWalk(db)) {
+			walk.addTree(commit2.getTree());
+			walk.next();
+			assertEquals(path2, walk.getPathString());
+			assertEquals(FileMode.EXECUTABLE_FILE, walk.getFileMode(0));
+			walk.next();
+			assertEquals(path, walk.getPathString());
+			assertEquals(FileMode.REGULAR_FILE, walk.getFileMode(0));
+		}
 	}
 
 	@Test