Fix availability validation for LOCAL_ONE CL

patch by Aleksey Yeschenko; reviewed by Sylvain Lebresne for
CASSANDRA-7319

CHANGES.txt

@@ -25,6 +25,7 @@
  * reduce garbage creation in calculatePendingRanges (CASSANDRA-7191)
  * exit CQLSH with error status code if script fails (CASSANDRA-6344)
  * Fix bug with some IN queries missig results (CASSANDRA-7105)
+ * Fix availability validation for LOCAL_ONE CL (CASSANDRA-7319)
 
 
 1.2.16

src/java/org/apache/cassandra/db/ConsistencyLevel.java

@@ -249,6 +249,10 @@ public enum ConsistencyLevel
             case ANY:
                 // local hint is acceptable, and local node is always live
                 break;
+            case LOCAL_ONE:
+                if (countLocalEndpoints(liveEndpoints) == 0)
+                    throw new UnavailableException(this, 1, 0);
+                break;
             case LOCAL_QUORUM:
                 int localLive = countLocalEndpoints(liveEndpoints);
                 if (localLive < blockFor)