Validate empty cell names from counter updates

patch by Aleksey Yeschenko; reviewed by Jeremiah Jordan for
CASSANDRA-7798

CHANGES.txt

@@ -1,4 +1,5 @@
 1.2.19
+ * Validate empty cell names from counter updates (CASSANDRA-7798)
  * Improve PasswordAuthenticator default super user setup (CASSANDRA-7788)
  * Remove duplicates from StorageService.getJoiningNodes (CASSANDRA-7478)
  * Clone token map outside of hot gossip loops (CASSANDRA-7758)

src/java/org/apache/cassandra/cql3/Constants.java

@@ -326,7 +326,7 @@ public abstract class Constants
                 throw new InvalidRequestException("Invalid null value for counter increment");
             long increment = ByteBufferUtil.toLong(bytes);
             ByteBuffer cname = columnName == null ? prefix.build() : prefix.add(columnName.key).build();
-            cf.addCounter(new QueryPath(cf.metadata().cfName, null, cname), increment);
+            cf.addColumn(params.makeCounter(cname, increment));
         }
     }
 
@@ -348,7 +348,7 @@ public abstract class Constants
                 throw new InvalidRequestException("The negation of " + increment + " overflows supported counter precision (signed 8 bytes integer)");
 
             ByteBuffer cname = columnName == null ? prefix.build() : prefix.add(columnName.key).build();
-            cf.addCounter(new QueryPath(cf.metadata().cfName, null, cname), -increment);
+            cf.addColumn(params.makeCounter(cname, -increment));
         }
     }
 

src/java/org/apache/cassandra/cql3/UpdateParameters.java

@@ -57,6 +57,12 @@ public class UpdateParameters
              : new Column(name, value, timestamp);
     }
 
+    public Column makeCounter(ByteBuffer name, long delta) throws InvalidRequestException
+    {
+        QueryProcessor.validateColumnName(name);
+        return new CounterUpdateColumn(name, delta, System.currentTimeMillis());
+    }
+
     public Column makeTombstone(ByteBuffer name) throws InvalidRequestException
     {
         QueryProcessor.validateColumnName(name);