Repair unsafe/unportable snprintf usage in pg_restore.

tglsfdc · tglsfdc · commit ed46d0d322b5 · 2019-02-09T19:45:38.000-05:00
warn_or_exit_horribly() was blithely passing a potentially-NULL
string pointer to a %s format specifier.  That works (at least
to the extent of not crashing) on some platforms, but not all,
and since we switched to our own snprintf.c it doesn't work
for us anywhere.

Of the three string fields being handled this way here, I think
that only "owner" is supposed to be nullable ... but considering
that this is error-reporting code, it has very little business
assuming anything, so put in defenses for all three.

Per a crash observed on buildfarm member crake and then
reproduced here.  Because of the portability aspect,
back-patch to all supported versions.
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
@@ -1676,8 +1676,11 @@ warn_or_exit_horribly(ArchiveHandle *AH,
 	{
 		write_msg(modulename, "Error from TOC entry %d; %u %u %s %s %s\n",
 				  AH->currentTE->dumpId,
-			 AH->currentTE->catalogId.tableoid, AH->currentTE->catalogId.oid,
-			  AH->currentTE->desc, AH->currentTE->tag, AH->currentTE->owner);
+				  AH->currentTE->catalogId.tableoid,
+				  AH->currentTE->catalogId.oid,
+				  AH->currentTE->desc ? AH->currentTE->desc : "(no desc)",
+				  AH->currentTE->tag ? AH->currentTE->tag : "(no tag)",
+				  AH->currentTE->owner ? AH->currentTE->owner : "(no owner)");
 	}
 	AH->lastErrorStage = AH->stage;
 	AH->lastErrorTE = AH->currentTE;

Original file line number	Diff line number	Diff line change
`@@ -1676,8 +1676,11 @@ warn_or_exit_horribly(ArchiveHandle *AH,`
`1676`	`1676`	`{`
`1677`	`1677`	`write_msg(modulename, "Error from TOC entry %d; %u %u %s %s %s\n",`
`1678`	`1678`	`AH->currentTE->dumpId,`
`1679`		`- AH->currentTE->catalogId.tableoid, AH->currentTE->catalogId.oid,`
`1680`		`- AH->currentTE->desc, AH->currentTE->tag, AH->currentTE->owner);`
	`1679`	`+ AH->currentTE->catalogId.tableoid,`
	`1680`	`+ AH->currentTE->catalogId.oid,`
	`1681`	`+ AH->currentTE->desc ? AH->currentTE->desc : "(no desc)",`
	`1682`	`+ AH->currentTE->tag ? AH->currentTE->tag : "(no tag)",`
	`1683`	`+ AH->currentTE->owner ? AH->currentTE->owner : "(no owner)");`
`1681`	`1684`	`}`
`1682`	`1685`	`AH->lastErrorStage = AH->stage;`
`1683`	`1686`	`AH->lastErrorTE = AH->currentTE;`