Set pg_setting.pending_restart when pertinent config lines are removed

This changes the behavior of examining the pg_file_settings view after
changing a config option that requires restart.  The user needs to know
that any change of such options does not take effect until a restart,
and this worked correctly if the line is edited without removing it.
However, for the case where the line is removed altogether, the flag
doesn't get set, because a flag was only set in set_config_option, but
that's not called for lines removed.  Repair.

(Ref.: commits 62d16c7fc561 and a486e35706ea)

Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/202107262302.xsfdfc5sb7sh@alvherre.pgsql

diff --git a/src/backend/utils/misc/guc-file.l b/src/backend/utils/misc/guc-file.l
index 986ce542e372d50b6a4a92dbd5c372bee2dd52a8..8ca74c801ccceb351c057b878b6644e78f1708fb 100644 (file)
--- a/src/backend/utils/misc/guc-file.l
+++ b/src/backend/utils/misc/guc-file.l
@@ -346,6 +346,8 @@ ProcessConfigFileInternal(GucContext context, bool applySettings, int elevel)
                        continue;
                if (gconf->context < PGC_SIGHUP)
                {
+                       /* The removal can't be effective without a restart */
+                       gconf->status |= GUC_PENDING_RESTART;
                        ereport(elevel,
                                        (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
                                         errmsg("parameter \"%s\" cannot be changed without restarting the server",