CPP: Fix QLDoc comments.

Author: geoffw0

cpp/ql/src/Security/CWE/CWE-311/CleartextTransmission.ql

@@ -35,7 +35,7 @@ abstract class NetworkSendRecv extends FunctionCall {
 /**
  * A function call that sends data over a network.
  *
- * note: functions such as `read` may be reading from a network source or a file. We could attempt to determine which, and sort results into `cpp/cleartext-transmission` and perhaps `cpp/cleartext-storage-file`. In practice it probably isn't very important which query reports a result as long as its reported exactly once.
+ * note: functions such as `write` may be writing to a network source or a file. We could attempt to determine which, and sort results into `cpp/cleartext-transmission` and perhaps `cpp/cleartext-storage-file`. In practice it usually isn't very important which query reports a result as long as its reported exactly once.
  */
 class NetworkSend extends NetworkSendRecv {
   NetworkSend() {
@@ -76,6 +76,8 @@ class SensitiveSendRecvConfiguration extends TaintTracking::Configuration {
   override predicate isSink(DataFlow::Node sink) {
     exists(NetworkSendRecv transmission |
       sink.asExpr() = transmission.getDataExpr() and
+
+      // a zero file descriptor is standard input, which is not interesting for this query.
       not exists(Zero zero |
         DataFlow::localFlow(DataFlow::exprNode(zero),
           DataFlow::exprNode(transmission.getSocketExpr()))