refuse to decomission if not in state NORMAL

patch by Jan Karlsson and Stefania for CASSANDRA-8741

CHANGES.txt

@@ -10,6 +10,8 @@ Merged from 2.1:
  * Change streaming_socket_timeout_in_ms default to 1 hour (CASSANDRA-8611)
  * (cqlsh) update list of CQL keywords (CASSANDRA-9232)
  * Add nodetool gettraceprobability command (CASSANDRA-10234)
+Merged from 2.0:
+ * Disallow decommission when node is in drained state (CASSANDRA-8741)
 
 
 2.2.1

src/java/org/apache/cassandra/service/StorageService.java

@@ -3294,6 +3294,8 @@ public class StorageService extends NotificationBroadcasterSupport implements IE
             throw new UnsupportedOperationException("local node is not a member of the token ring yet");
         if (tokenMetadata.cloneAfterAllLeft().sortedTokens().size() < 2)
             throw new UnsupportedOperationException("no other normal nodes in the ring; decommission would be pointless");
+        if (operationMode != Mode.NORMAL)
+            throw new UnsupportedOperationException("Node in " + operationMode + " state; wait for status to become normal or restart");
 
         PendingRangeCalculatorService.instance.blockUntilFinished();
         for (String keyspaceName : Schema.instance.getNonSystemKeyspaces())

src/java/org/apache/cassandra/tools/nodetool/Decommission.java

@@ -34,6 +34,9 @@ public class Decommission extends NodeToolCmd
         } catch (InterruptedException e)
         {
             throw new RuntimeException("Error decommissioning node", e);
+        } catch (UnsupportedOperationException e)
+        {
+            throw new IllegalStateException("Unsupported operation: " + e.getMessage(), e);
         }
     }
 }