SshSupport#runSshCommand: don't throw exception in finally block

The CommandFailedException which was thrown in finally block is silently
discarded [1]. Refactor this method to throw the exception after the
finally block.

This fixes the warning "Null comparison always yields false: The
variable failure can only be null at this location".

[1] https://wiki.sei.cmu.edu/confluence/display/java/ERR04-J.+Do+not+complete+abruptly+from+a+finally+block
https://docs.oracle.com/javase/specs/jls/se8/html/jls-14.html#jls-14.20.2

Change-Id: Idbfc303d9c9046ab9a43e0d4c6d65d325bdaf0ed
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit/src/org/eclipse/jgit/util/SshSupport.java

@@ -94,6 +94,7 @@ public class SshSupport {
 		CommandFailedException failure = null;
 		@SuppressWarnings("resource")
 		MessageWriter stderr = new MessageWriter();
+		String out;
 		try (MessageWriter stdout = new MessageWriter()) {
 			session = SshSessionFactory.getInstance().getSession(sshUri,
 					provider, fs, 1000 * timeout);
@@ -108,12 +109,12 @@ public class SshSupport {
 				// waitFor with timeout has a bug - JSch' exitValue() throws the
 				// wrong exception type :(
 				if (process.waitFor() == 0) {
-					return stdout.toString();
+					out = stdout.toString();
 				} else {
-					return null; // still running after timeout
+					out = null; // still running after timeout
 				}
 			} catch (InterruptedException e) {
-				return null; // error
+				out = null; // error
 			}
 		} finally {
 			if (errorThread != null) {
@@ -147,10 +148,11 @@ public class SshSupport {
 			if (session != null) {
 				SshSessionFactory.getInstance().releaseSession(session);
 			}
-			if (failure != null) {
-				throw failure;
-			}
 		}
+		if (failure != null) {
+			throw failure;
+		}
+		return out;
 	}
 
 }