Document the intended use of RepoCommand#setURI()

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Change-Id: I4a59dd8278b7b0026094692127b7f55e89c10bae

org.eclipse.jgit/src/org/eclipse/jgit/gitrepo/RepoCommand.java

@@ -264,7 +264,11 @@ public class RepoCommand extends GitCommand<RevCommit> {
 	}
 
 	/**
-	 * Set base URI of the pathes inside the XML
+	 * Set base URI of the paths inside the XML. This is typically the name of
+	 * the directory holding the manifest repository, eg. for
+	 * https://android.googlesource.com/platform/manifest, this should be
+	 * /platform (if you would run this on android.googlesource.com)
+	 * or https://android.googlesource.com/platform elsewhere.
 	 *
 	 * @param uri
 	 * @return this command
@@ -448,9 +452,10 @@ public class RepoCommand extends GitCommand<RevCommit> {
 	public RevCommit call() throws GitAPIException {
 		try {
 			checkCallable();
-			if (uri == null || uri.length() == 0)
+			if (uri == null || uri.length() == 0) {
 				throw new IllegalArgumentException(
 					JGitText.get().uriNotConfigured);
+			}
 			if (inputStream == null) {
 				if (manifestPath == null || manifestPath.length() == 0)
 					throw new IllegalArgumentException(