Avoid uninitialized value error in TAP tests' Cluster->psql

If the method is called in scalar context and we didn't pass in a stderr
handle, one won't be created. However, some error paths assume that it
exists, so in this case create a dummy stderr to avoid the resulting
perl error.

Per gripe from Oleg Tselebrovskiy  and
adapted from his patch.

Discussion: https://postgr.es/m/378eac5de4b8ecb5be7bcdf2db9d2c4d@postgrespro.ru

diff --git a/src/test/perl/PostgreSQL/Test/Cluster.pm b/src/test/perl/PostgreSQL/Test/Cluster.pm
index 49b2c86b29cbf61f2f327b4e08545c6b97f379e8..301766d2ed93c4b87cb156bbe9b436a68b4c6199 100644 (file)
--- a/src/test/perl/PostgreSQL/Test/Cluster.pm
+++ b/src/test/perl/PostgreSQL/Test/Cluster.pm
@@ -2199,6 +2199,14 @@ sub psql
            $ret = $?;
        };
        my $exc_save = $@;
+
+       # we need a dummy $stderr from hereon, if we didn't collect it
+       if (! defined $stderr)
+       {
+           my $errtxt = "";
+           $stderr = \$errtxt;
+       }
+
        if ($exc_save)
        {