Re: lib/sort.t failure (and [PATCH])

From: "John P. Linderman" <jpl@research.att.com>
Message-ID: <200204051213.HAA13004@raptor.research.att.com>

p4raw-id: //depot/perl@15741

diff --git a/lib/sort.t b/lib/sort.t
index c132a5c..52d1d8b 100644 (file)
--- a/lib/sort.t
+++ b/lib/sort.t
@@ -58,15 +58,18 @@ sub genarray {
 sub checkorder {
     my $aref = shift;
     my $status = '';                   # so far, so good
-    my $i;
+    my ($i, $disorder);
 
     for ($i = 0; $i < $#$aref; ++$i) {
-       next if ($aref->[$i] lt $aref->[$i+1]);
-       $status = (substr($aref->[$i], 0, $RootWidth) eq
-                  substr($aref->[$i+1], 0, $RootWidth)) ?
-                 "Instability" : "Disorder";
-       $status .= " at element $i between $aref->[$i] and $aref->[$i+1]";
-       last;
+       # Equality shouldn't happen, but catch it in the contents check
+       next if ($aref->[$i] le $aref->[$i+1]);
+       $disorder = (substr($aref->[$i],   0, $RootWidth) eq
+                    substr($aref->[$i+1], 0, $RootWidth)) ?
+                    "Instability" : "Disorder";
+       # Keep checking if merely unstable... disorder is much worse.
+       $status =
+           "$disorder at element $i between $aref->[$i] and $aref->[$i+1]";
+       last unless ($disorder eq "Instability");       
     }
     return $status;
 }
@@ -121,6 +124,11 @@ sub main {
        $status = checkequal(\@sorted, $unsorted);
        is($status, '', "contents ok for size $ts");
     }
+    # P5P: The following test (#58) has been observed failing on
+    # a solaris 2.8 platform.  Failure doesn't mean that sort is
+    # misbehaving, it is just exhibiting an exceedingly unlikely
+    # pattern of breaking ties.  If you see no other failures,
+    # it should be perfectly safe to install.
     if ($expect_unstable) {
        ok($unstable_num > 0, 'Instability ok');
     }