Forbid invalid combination of options in pg_basebackup.

MasaoFujii · MasaoFujii · commit ecbdc4c555f4 · 2016-12-21T20:27:37.000+09:00
Commit 56c7d8d allowed pg_basebackup to stream WAL in tar mode. But there is the restriction that WAL streaming in tar mode works only when the value - (dash) is not specified as output directory. This means that the combination of three options "-D -", "-F t" and "-X stream" is invalid. However, previously, even when those options were specified at the same time, pg_basebackup background process unexpectedly started streaming WAL. And then it exited with an error. This commit changes pg_basebackup so that it errors out on such invalid combination of options at the beginning. Reviewed by Magnus Hagander, and patch by me.
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
@@ -2268,6 +2268,16 @@ main(int argc, char **argv)
 		exit(1);
 	}
 
+	if (format == 't' && streamwal && strcmp(basedir, "-") == 0)
+	{
+		fprintf(stderr,
+			_("%s: cannot stream transaction logs in tar mode to stdout\n"),
+				progname);
+		fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
+				progname);
+		exit(1);
+	}
+
 	if (replication_slot && !streamwal)
 	{
 		fprintf(stderr,
