Add some asserts to pass static analysis (#3805)

src/backend/distributed/connection/connection_management.c

@@ -193,7 +193,16 @@ GetNodeConnection(uint32 flags, const char *hostname, int32 port)
 MultiConnection *
 StartNodeConnection(uint32 flags, const char *hostname, int32 port)
 {
-	return StartNodeUserDatabaseConnection(flags, hostname, port, NULL, NULL);
+	MultiConnection *connection = StartNodeUserDatabaseConnection(flags, hostname, port,
+																  NULL, NULL);
+
+	/*
+	 * connection can only be NULL for optional connections, which we don't
+	 * support in this codepath.
+	 */
+	Assert((flags & OPTIONAL_CONNECTION) == 0);
+	Assert(connection != NULL);
+	return connection;
 }
 
 
@@ -209,6 +218,13 @@ GetNodeUserDatabaseConnection(uint32 flags, const char *hostname, int32 port,
 	MultiConnection *connection = StartNodeUserDatabaseConnection(flags, hostname, port,
 																  user, database);
 
+	/*
+	 * connection can only be NULL for optional connections, which we don't
+	 * support in this codepath.
+	 */
+	Assert((flags & OPTIONAL_CONNECTION) == 0);
+	Assert(connection != NULL);
+
 	FinishConnectionEstablishment(connection);
 
 	return connection;
@@ -236,6 +252,13 @@ StartWorkerListConnections(List *workerNodeList, uint32 flags, const char *user,
 																	  nodeName, nodePort,
 																	  user, database);
 
+		/*
+		 * connection can only be NULL for optional connections, which we don't
+		 * support in this codepath.
+		 */
+		Assert((flags & OPTIONAL_CONNECTION) == 0);
+		Assert(connection != NULL);
+
 		connectionList = lappend(connectionList, connection);
 	}
 

src/backend/distributed/connection/placement_connection.c

@@ -294,6 +294,13 @@ StartPlacementListConnection(uint32 flags, List *placementAccessList,
 		chosenConnection = StartNodeUserDatabaseConnection(flags, nodeName, nodePort,
 														   userName, NULL);
 
+		/*
+		 * chosenConnection can only be NULL for optional connections, which we
+		 * don't support in this codepath.
+		 */
+		Assert((flags & OPTIONAL_CONNECTION) == 0);
+		Assert(chosenConnection != NULL);
+
 		if ((flags & CONNECTION_PER_PLACEMENT) &&
 			ConnectionAccessedDifferentPlacement(chosenConnection, placement))
 		{
@@ -314,6 +321,13 @@ StartPlacementListConnection(uint32 flags, List *placementAccessList,
 															   nodeName, nodePort,
 															   userName, NULL);
 
+			/*
+			 * chosenConnection can only be NULL for optional connections,
+			 * which we don't support in this codepath.
+			 */
+			Assert((flags & OPTIONAL_CONNECTION) == 0);
+			Assert(chosenConnection != NULL);
+
 			Assert(!ConnectionAccessedDifferentPlacement(chosenConnection, placement));
 		}
 	}

src/backend/distributed/executor/multi_client_executor.c

@@ -150,6 +150,13 @@ MultiClientConnectStart(const char *nodeName, uint32 nodePort, const char *nodeD
 	MultiConnection *connection = StartNodeUserDatabaseConnection(connectionFlags,
 																  nodeName, nodePort,
 																  userName, nodeDatabase);
+
+	/*
+	 * connection can only be NULL for optional connections, which we don't
+	 * support in this codepath.
+	 */
+	Assert((connectionFlags & OPTIONAL_CONNECTION) == 0);
+	Assert(connection != NULL);
 	ConnStatusType connStatusType = PQstatus(connection->pgConn);
 
 	/*

src/backend/distributed/transaction/worker_transaction.c

@@ -409,6 +409,13 @@ OpenConnectionsToWorkersInParallel(TargetWorkerSet targetWorkerSet, const char *
 		MultiConnection *connection = StartNodeUserDatabaseConnection(connectionFlags,
 																	  nodeName, nodePort,
 																	  user, NULL);
+
+		/*
+		 * connection can only be NULL for optional connections, which we don't
+		 * support in this codepath.
+		 */
+		Assert((connectionFlags & OPTIONAL_CONNECTION) == 0);
+		Assert(connection != NULL);
 		connectionList = lappend(connectionList, connection);
 	}
 	return connectionList;
@@ -476,6 +483,12 @@ SendCommandToWorkersParamsInternal(TargetWorkerSet targetWorkerSet, const char *
 																	  nodeName, nodePort,
 																	  user, NULL);
 
+		/*
+		 * connection can only be NULL for optional connections, which we don't
+		 * support in this codepath.
+		 */
+		Assert((connectionFlags & OPTIONAL_CONNECTION) == 0);
+		Assert(connection != NULL);
 		MarkRemoteTransactionCritical(connection);
 
 		connectionList = lappend(connectionList, connection);