Allow Repository.getDirectory() to be null

Some types of repositories might not be stored on local disk.  For
these, they will most likely return null for getDirectory() as the
java.io.File type cannot describe where their storage is, its not
in the host's filesystem.

Document that getDirectory() can return null now, and update all
current non-test callers in JGit that might run into problems on
such repositories.  For the most part, just act like its bare.

Change-Id: I061236a691372a267fd7d41f0550650e165d2066
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

org.eclipse.jgit.http.server/src/org/eclipse/jgit/http/server/TextFileServlet.java

@@ -80,6 +80,8 @@ class TextFileServlet extends HttpServlet {
 
 	private byte[] read(final HttpServletRequest req) throws IOException {
 		final File gitdir = getRepository(req).getDirectory();
+		if (gitdir == null)
+			throw new FileNotFoundException(fileName);
 		return IO.readFully(new File(gitdir, fileName));
 	}
 }

org.eclipse.jgit.http.server/src/org/eclipse/jgit/http/server/resolver/FileResolver.java

@@ -138,8 +138,10 @@ public class FileResolver implements RepositoryResolver {
 			Repository db) throws IOException {
 		if (isExportAll())
 			return true;
-		else
+		else if (db.getDirectory() != null)
 			return new File(db.getDirectory(), "git-daemon-export-ok").exists();
+		else
+			return false;
 	}
 
 	private static boolean isUnreasonableName(final String name) {

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

@@ -125,10 +125,12 @@ class Glog extends RevWalkTextBuiltin {
 	}
 
 	private String repoName() {
-		final File f = db.getDirectory();
-		String n = f.getName();
+		final File gitDir = db.getDirectory();
+		if (gitDir == null)
+			return db.toString();
+		String n = gitDir.getName();
 		if (Constants.DOT_GIT.equals(n))
-			n = f.getParentFile().getName();
+			n = gitDir.getParentFile().getName();
 		return n;
 	}
 }

org.eclipse.jgit/src/org/eclipse/jgit/api/CommitCommand.java

@@ -171,17 +171,18 @@ public class CommitCommand extends GitCommand<RevCommit> {
 					Result rc = ru.update();
 					switch (rc) {
 					case NEW:
-					case FAST_FORWARD:
+					case FAST_FORWARD: {
 						setCallable(false);
-						if (state == RepositoryState.MERGING_RESOLVED) {
+						File meta = repo.getDirectory();
+						if (state == RepositoryState.MERGING_RESOLVED
+								&& meta != null) {
 							// Commit was successful. Now delete the files
 							// used for merge commits
-							new File(repo.getDirectory(), Constants.MERGE_HEAD)
-									.delete();
-							new File(repo.getDirectory(), Constants.MERGE_MSG)
-									.delete();
+							new File(meta, Constants.MERGE_HEAD).delete();
+							new File(meta, Constants.MERGE_MSG).delete();
 						}
 						return revCommit;
+					}
 					case REJECTED:
 					case LOCK_FAILURE:
 						throw new ConcurrentRefUpdateException(

org.eclipse.jgit/src/org/eclipse/jgit/lib/Repository.java

@@ -165,9 +165,7 @@ public abstract class Repository {
 	 */
 	public abstract void create(boolean bare) throws IOException;
 
-	/**
-	 * @return GIT_DIR
-	 */
+	/** @return local metadata directory; null if repository isn't local. */
 	public File getDirectory() {
 		return gitDir;
 	}
@@ -712,7 +710,13 @@ public abstract class Repository {
 	public abstract void openPack(File pack, File idx) throws IOException;
 
 	public String toString() {
-		return "Repository[" + getDirectory() + "]";
+		String desc;
+		if (getDirectory() != null)
+			desc = getDirectory().getPath();
+		else
+			desc = getClass().getSimpleName() + "-"
+					+ System.identityHashCode(this);
+		return "Repository[" + desc + "]";
 	}
 
 	/**
@@ -908,7 +912,7 @@ public abstract class Repository {
 	 * @return an important state
 	 */
 	public RepositoryState getRepositoryState() {
-		if (isBare())
+		if (isBare() || getDirectory() == null)
 			return RepositoryState.BARE;
 
 		// Pre Git-1.6 logic
@@ -1096,7 +1100,7 @@ public abstract class Repository {
 	 *             if the repository is "bare"
 	 */
 	public String readMergeCommitMsg() throws IOException {
-		if (isBare())
+		if (isBare() || getDirectory() == null)
 			throw new IllegalStateException(
 					JGitText.get().bareRepositoryNoWorkdirAndIndex);
 
@@ -1123,7 +1127,7 @@ public abstract class Repository {
 	 *             if the repository is "bare"
 	 */
 	public List<ObjectId> readMergeHeads() throws IOException {
-		if (isBare())
+		if (isBare() || getDirectory() == null)
 			throw new IllegalStateException(
 					JGitText.get().bareRepositoryNoWorkdirAndIndex);
 

org.eclipse.jgit/src/org/eclipse/jgit/lib/RepositoryCache.java

@@ -120,7 +120,10 @@ public class RepositoryCache {
 	 *            repository to register.
 	 */
 	public static void register(final Repository db) {
-		cache.registerRepository(FileKey.exact(db.getDirectory(), db.getFS()), db);
+		if (db.getDirectory() != null) {
+			FileKey key = FileKey.exact(db.getDirectory(), db.getFS());
+			cache.registerRepository(key, db);
+		}
 	}
 
 	/**
@@ -133,7 +136,10 @@ public class RepositoryCache {
 	 *            repository to unregister.
 	 */
 	public static void close(final Repository db) {
-		cache.unregisterRepository(FileKey.exact(db.getDirectory(), db.getFS()));
+		if (db.getDirectory() != null) {
+			FileKey key = FileKey.exact(db.getDirectory(), db.getFS());
+			cache.unregisterRepository(key);
+		}
 	}
 
 	/** Unregister all repositories from the cache. */

org.eclipse.jgit/src/org/eclipse/jgit/transport/FetchProcess.java

@@ -271,8 +271,10 @@ class FetchProcess {
 	}
 
 	private void updateFETCH_HEAD(final FetchResult result) throws IOException {
-		final LockFile lock = new LockFile(new File(transport.local
-				.getDirectory(), "FETCH_HEAD"));
+		File meta = transport.local.getDirectory();
+		if (meta == null)
+			return;
+		final LockFile lock = new LockFile(new File(meta, "FETCH_HEAD"));
 		try {
 			if (lock.lock()) {
 				final Writer w = new OutputStreamWriter(lock.getOutputStream());

org.eclipse.jgit/src/org/eclipse/jgit/transport/RemoteRefUpdate.java

@@ -357,6 +357,6 @@ public class RemoteRefUpdate {
 				+ "..." + (newObjectId != null ? newObjectId.abbreviate(localDb).name() : "(null)")
 				+ (fastForward ? ", fastForward" : "")
 				+ ", srcRef=" + srcRef + (forceUpdate ? ", forceUpdate" : "") + ", message=" + (message != null ? "\""
-				+ message + "\"" : "null") + ", " + localDb.getDirectory() + "]";
+				+ message + "\"" : "null") + "]";
 	}
 }