Allow specifying pg_waldump --rmgr option multiple times.

Before, if you specified multiple --rmgr options, only the last one took
effect. It seems more sensible to select all the specified resource
managers.

Reviewed-By: Daniel Gustafsson, Julien Rouhaud
Discussion: https://www.postgresql.org/message-id/98344bc2-e222-02ad-a75b-81ffc614c155%40iki.fi

doc/src/sgml/ref/pg_waldump.sgml

@@ -142,7 +142,8 @@ PostgreSQL documentation
       <term><option>--rmgr=<replaceable>rmgr</replaceable></option></term>
       <listitem>
        <para>
-        Only display records generated by the specified resource manager.
+        Only display records generated by the specified resource manager. You can
+        specify the option multiple times to select multiple resource managers.
         If <literal>list</literal> is passed as name, print a list of valid resource manager
         names, and exit.
        </para>

src/bin/pg_waldump/pg_waldump.c

@@ -49,7 +49,8 @@ typedef struct XLogDumpConfig
 	bool		stats_per_record;
 
 	/* filter options */
-	int			filter_by_rmgr;
+	bool		filter_by_rmgr[RM_MAX_ID + 1];
+	bool		filter_by_rmgr_enabled;
 	TransactionId filter_by_xid;
 	bool		filter_by_xid_enabled;
 } XLogDumpConfig;
@@ -825,7 +826,8 @@ main(int argc, char **argv)
 	config.stop_after_records = -1;
 	config.already_displayed_records = 0;
 	config.follow = false;
-	config.filter_by_rmgr = -1;
+	/* filter_by_rmgr array was zeroed by memset above */
+	config.filter_by_rmgr_enabled = false;
 	config.filter_by_xid = InvalidTransactionId;
 	config.filter_by_xid_enabled = false;
 	config.stats = false;
@@ -884,12 +886,12 @@ main(int argc, char **argv)
 					{
 						if (pg_strcasecmp(optarg, RmgrDescTable[i].rm_name) == 0)
 						{
-							config.filter_by_rmgr = i;
+							config.filter_by_rmgr[i] = true;
+							config.filter_by_rmgr_enabled = true;
 							break;
 						}
 					}
-
-					if (config.filter_by_rmgr == -1)
+					if (i > RM_MAX_ID)
 					{
 						pg_log_error("resource manager \"%s\" does not exist",
 									 optarg);
@@ -1098,8 +1100,8 @@ main(int argc, char **argv)
 		}
 
 		/* apply all specified filters */
-		if (config.filter_by_rmgr != -1 &&
-			config.filter_by_rmgr != record->xl_rmid)
+		if (config.filter_by_rmgr_enabled &&
+			!config.filter_by_rmgr[record->xl_rmid])
 			continue;
 
 		if (config.filter_by_xid_enabled &&