pgm: Handle exceptions in Merge command

This avoids we show a stacktrace on the console by default when this
type of exception is thrown during the run method is executed.

Change-Id: I7afd038d8def9d2f409c0ed297b9db8ea2fc75c1
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

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

@@ -52,6 +52,7 @@ import org.eclipse.jgit.api.MergeCommand;
 import org.eclipse.jgit.api.MergeCommand.FastForwardMode;
 import org.eclipse.jgit.api.MergeResult;
 import org.eclipse.jgit.api.errors.CheckoutConflictException;
+import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.lib.AnyObjectId;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
@@ -103,7 +104,7 @@ class Merge extends TextBuiltin {
 
 	/** {@inheritDoc} */
 	@Override
-	protected void run() throws Exception {
+	protected void run() {
 		if (squash && ff == FastForwardMode.NO_FF)
 			throw die(CLIText.get().cannotCombineSquashWithNoff);
 		// determine the merge strategy
@@ -114,18 +115,20 @@ class Merge extends TextBuiltin {
 						CLIText.get().unknownMergeStrategy, strategyName));
 		}
 
+		try {
 			// determine the other revision we want to merge with HEAD
 			final Ref srcRef = db.findRef(ref);
 			final ObjectId src = db.resolve(ref + "^{commit}"); //$NON-NLS-1$
 			if (src == null)
-			throw die(MessageFormat.format(
-					CLIText.get().refDoesNotExistOrNoCommit, ref));
+				throw die(MessageFormat
+						.format(CLIText.get().refDoesNotExistOrNoCommit, ref));
 
 			Ref oldHead = getOldHead();
 			MergeResult result;
 			try (Git git = new Git(db)) {
 				MergeCommand mergeCmd = git.merge().setStrategy(mergeStrategy)
-					.setSquash(squash).setFastForward(ff).setCommit(!noCommit);
+						.setSquash(squash).setFastForward(ff)
+						.setCommit(!noCommit);
 				if (srcRef != null)
 					mergeCmd.include(srcRef);
 				else
@@ -152,8 +155,8 @@ class Merge extends TextBuiltin {
 				if (oldHeadId != null) {
 					String oldId = oldHeadId.abbreviate(7).name();
 					String newId = result.getNewHead().abbreviate(7).name();
-				outw.println(MessageFormat.format(CLIText.get().updating, oldId,
-						newId));
+					outw.println(MessageFormat.format(CLIText.get().updating,
+							oldId, newId));
 				}
 				outw.println(result.getMergeStatus().toString());
 				break;
@@ -165,8 +168,8 @@ class Merge extends TextBuiltin {
 				break;
 			case CONFLICTING:
 				for (String collidingPath : result.getConflicts().keySet())
-				outw.println(MessageFormat.format(CLIText.get().mergeConflict,
-						collidingPath));
+					outw.println(MessageFormat.format(
+							CLIText.get().mergeConflict, collidingPath));
 				outw.println(CLIText.get().mergeFailed);
 				break;
 			case FAILED:
@@ -190,16 +193,19 @@ class Merge extends TextBuiltin {
 					name = mergeStrategy.getName();
 				else
 					name = "recursive"; //$NON-NLS-1$
-			outw.println(MessageFormat.format(CLIText.get().mergeMadeBy, name));
+				outw.println(
+						MessageFormat.format(CLIText.get().mergeMadeBy, name));
 				break;
 			case MERGED_NOT_COMMITTED:
-			outw.println(CLIText.get().mergeWentWellStoppedBeforeCommitting);
+				outw.println(
+						CLIText.get().mergeWentWellStoppedBeforeCommitting);
 				break;
 			case MERGED_SQUASHED:
 			case FAST_FORWARD_SQUASHED:
 			case MERGED_SQUASHED_NOT_COMMITTED:
 				outw.println(CLIText.get().mergedSquashed);
-			outw.println(CLIText.get().mergeWentWellStoppedBeforeCommitting);
+				outw.println(
+						CLIText.get().mergeWentWellStoppedBeforeCommitting);
 				break;
 			case ABORTED:
 				throw die(CLIText.get().ffNotPossibleAborting);
@@ -207,6 +213,10 @@ class Merge extends TextBuiltin {
 				outw.println(MessageFormat.format(
 						CLIText.get().unsupportedOperation, result.toString()));
 			}
+		} catch (GitAPIException | IOException e) {
+			throw die(e.getMessage(), e);
+		}
+
 	}
 
 	private Ref getOldHead() throws IOException {