GUACAMOLE-990: Merge change ensuring internal errors are correctly handed and logged.

guacamole/src/main/java/org/apache/guacamole/rest/auth/AuthenticationService.java

@@ -27,6 +27,7 @@ import javax.servlet.http.HttpServletRequest;
 
 import org.apache.guacamole.GuacamoleException;
 import org.apache.guacamole.GuacamoleSecurityException;
+import org.apache.guacamole.GuacamoleServerException;
 import org.apache.guacamole.GuacamoleUnauthorizedException;
 import org.apache.guacamole.GuacamoleSession;
 import org.apache.guacamole.environment.Environment;
@@ -480,6 +481,18 @@ public class AuthenticationService {
                         getLoggableAddress(request));
 
             // Rethrow exception
+            e.rethrowCause();
+
+            // This line SHOULD be unreachable unless a bug causes
+            // rethrowCause() to not actually rethrow the underlying failure
+            Throwable cause = e.getCause();
+            if (cause != null) {
+                logger.warn("An underlying internal error was not correctly rethrown by rethrowCause(): {}", cause.getMessage());
+                logger.debug("Internal error not rethrown by rethrowCause().", cause);
+            }
+            else
+                logger.warn("An underlying internal error was not correctly rethrown by rethrowCause().");
+
             throw e.getCauseAsGuacamoleException();
 
         }

guacamole/src/main/java/org/apache/guacamole/rest/auth/GuacamoleAuthenticationProcessException.java

@@ -146,6 +146,38 @@ public class GuacamoleAuthenticationProcessException extends GuacamoleException
         return guacCause;
     }
 
+    /**
+     * Rethrows the original GuacamoleException wrapped within this
+     * GuacamoleAuthenticationProcessException. If there is no such exception,
+     * and the cause of this failure is an unchecked RuntimeException or Error,
+     * that unchecked exception/error is rethrown as-is.
+     *
+     * @throws GuacamoleException
+     *     If the underlying cause of this exception is a checked
+     *     GuacamoleException subclass.
+     *
+     * @throws RuntimeException
+     *     If the underlying cause of this exception is an unchecked
+     *     RuntimeException.
+     *
+     * @throws Error
+     *     If the underlying cause of this exception is an unchecked Error.
+     */
+    public void rethrowCause() throws GuacamoleException, RuntimeException, Error {
+
+        // Rethrow any unchecked exceptions/errors as-is
+        Throwable cause = getCause();
+        if (cause instanceof RuntimeException)
+            throw (RuntimeException) cause;
+        if (cause instanceof Error)
+            throw (Error) cause;
+
+        // Pass through all other exceptions as normal GuacamoleException
+        // subclassses
+        throw getCauseAsGuacamoleException();
+
+    }
+
     @Override
     public GuacamoleStatus getStatus() {
         return getCauseAsGuacamoleException().getStatus();