Make libpqsrv_cancel's return const char *, not char *

alvherre · alvherre · commit b8b37e41ba4a · 2024-04-05T18:23:10.000+02:00
Per headerscheck's C++ check. Discussion: https://postgr.es/m/372769.1712179784@sss.pgh.pa.us
diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c
@@ -1347,7 +1347,7 @@ Datum
 dblink_cancel_query(PG_FUNCTION_ARGS)
 {
 	PGconn	   *conn;
-	char	   *msg;
+	const char *msg;
 	TimestampTz endtime;
 
 	dblink_init();
diff --git a/contrib/postgres_fdw/connection.c b/contrib/postgres_fdw/connection.c
@@ -1332,7 +1332,7 @@ pgfdw_cancel_query(PGconn *conn)
 static bool
 pgfdw_cancel_query_begin(PGconn *conn, TimestampTz endtime)
 {
-	char	   *errormsg = libpqsrv_cancel(conn, endtime);
+	const char *errormsg = libpqsrv_cancel(conn, endtime);
 
 	if (errormsg != NULL)
 		ereport(WARNING,
diff --git a/src/include/libpq/libpq-be-fe-helpers.h b/src/include/libpq/libpq-be-fe-helpers.h
@@ -382,11 +382,11 @@ libpqsrv_get_result(PGconn *conn, uint32 wait_event_info)
  * Note: this function leaks a string's worth of memory when reporting
  * libpq errors.  Make sure to call it in a transient memory context.
  */
-static inline char *
+static inline const char *
 libpqsrv_cancel(PGconn *conn, TimestampTz endtime)
 {
 	PGcancelConn *cancel_conn;
-	char	   *error = NULL;
+	const char *error = NULL;
 
 	cancel_conn = PQcancelCreate(conn);
 	if (cancel_conn == NULL)

Original file line number	Diff line number	Diff line change
`@@ -1347,7 +1347,7 @@ Datum`
`1347`	`1347`	`dblink_cancel_query(PG_FUNCTION_ARGS)`
`1348`	`1348`	`{`
`1349`	`1349`	`PGconn *conn;`
`1350`		`- char *msg;`
	`1350`	`+ const char *msg;`
`1351`	`1351`	`TimestampTz endtime;`
`1352`	`1352`
`1353`	`1353`	`dblink_init();`
Original file line number	Diff line number	Diff line change
`@@ -1332,7 +1332,7 @@ pgfdw_cancel_query(PGconn *conn)`
`1332`	`1332`	`static bool`
`1333`	`1333`	`pgfdw_cancel_query_begin(PGconn *conn, TimestampTz endtime)`
`1334`	`1334`	`{`
`1335`		`- char *errormsg = libpqsrv_cancel(conn, endtime);`
	`1335`	`+ const char *errormsg = libpqsrv_cancel(conn, endtime);`
`1336`	`1336`
`1337`	`1337`	`if (errormsg != NULL)`
`1338`	`1338`	`ereport(WARNING,`