Merge branch 'tr/perl-keep-stderr-open'

Closing (not redirecting to /dev/null) the standard error stream is
not a very smart thing to do.  Later open may return file
descriptor #2 for unrelated purpose, and error reporting code may
write into them.

* tr/perl-keep-stderr-open:
  t9700: do not close STDERR
  perl: redirect stderr to /dev/null instead of closing

t/t9700/test.pl

@@ -45,7 +45,8 @@ is($r->get_color("color.test.slot1", "red"), $ansi_green, "get_color");
 # Failure cases for config:
 # Save and restore STDERR; we will probably extract this into a
 # "dies_ok" method and possibly move the STDERR handling to Git.pm.
-open our $tmpstderr, ">&STDERR" or die "cannot save STDERR"; close STDERR;
+open our $tmpstderr, ">&STDERR" or die "cannot save STDERR";
+open STDERR, ">", "/dev/null" or die "cannot redirect STDERR to /dev/null";
 is($r->config("test.dupstring"), "value2", "config: multivar");
 eval { $r->config_bool("test.boolother") };
 ok($@, "config_bool: non-boolean values fail");