What does an empty PERLIO= mean, anyway?

p4raw-id: //depot/perl@19237

diff --git a/t/io/layers.t b/t/io/layers.t
index 55be7cf..6f161cd 100644 (file)
--- a/t/io/layers.t
+++ b/t/io/layers.t
@@ -8,6 +8,10 @@ BEGIN {
        print "1..0 # Skip: not perlio\n";
        exit 0;
     }
+    if (exists $ENV{PERLIO} && $ENV{PERLIO} !~ /^(stdio|perlio|mmap)$/) {
+       print "1..0 # PERLIO='$ENV{PERLIO}' unknown\n";
+       exit 0;
+    }
 }
 
 plan tests => 43;
@@ -36,7 +40,8 @@ SKIP: {
                ok($j->($result->[$i]), "$id - $i is ok");
            } else {
                is($result->[$i], $j,
-                  sprintf("$id - $i is %s", defined $j ? $j : "undef"));
+                  sprintf("$id - $i is %s",
+                          defined $j ? $j : "undef"));
            }
        }
     }