Fix ephemeral consumer delete in single cluster

Also remove retry of sources/mirror in the setSourceConsumer() itself
when not getting a response.

Signed-off-by: Ivan Kozlovic <ivan@synadia.com>

server/gateway.go

@@ -2018,6 +2018,12 @@ func (c *client) gatewayInterest(acc, subj string) (bool, *SublistResult) {
 			}
 		}
 		e.RUnlock()
+		// Since callers may just check if the sublist result is nil or not,
+		// make sure that if what is returned by sl.Match() is the emptyResult, then
+		// we return nil to the caller.
+		if r == emptyResult {
+			r = nil
+		}
 	}
 	return psi, r
 }

server/stream.go

@@ -1278,7 +1278,7 @@ func (mset *stream) setupMirrorConsumer() error {
 			}
 			mset.setMirrorErr(ccr.Error)
 		case <-time.After(10 * time.Second):
-			mset.resetMirrorConsumer()
+			return
 		}
 	}()
 
@@ -1434,12 +1434,7 @@ func (mset *stream) setSourceConsumer(sname string, seq uint64) {
 			}
 			mset.mu.Unlock()
 		case <-time.After(10 * time.Second):
-			// Make sure things have not changed.
-			mset.mu.Lock()
-			if si := mset.sources[sname]; si != nil && si.cname == _EMPTY_ {
-				mset.setSourceConsumer(sname, seq)
-			}
-			mset.mu.Unlock()
+			return
 		}
 	}()
 }
@@ -2547,10 +2542,6 @@ func (mset *stream) stop(deleteFlag, advisory bool) error {
 		}
 	}
 
-	if deleteFlag {
-		mset.stopSourceConsumers()
-	}
-
 	// Send stream delete advisory after the consumers.
 	if deleteFlag && advisory {
 		mset.sendDeleteAdvisoryLocked()