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[PATCH] cvsserver: Determinize output to combat Perl 5.18 hash randomization

From
Anders Kaseorg <andersk@mit.edu>
Date
Oct 30, 2013, 08:44 UTC
Message-ID
<alpine.DEB.2.00.1310300413430.20647@dr-wily.mit.edu>
Perl 5.18 randomizes the seed used by its hash function, so iterating
through hashes results in different orders from run to run:
  http://perldoc.perl.org/perl5180delta.html#Hash-overhaul

This usually broke t9400 (gitcvs.dbname, gitcvs.ext.dbname, when running cmp on two .sqlite files) and t9402 (check [cvswork3] diff, when running test_cmp on two diffs).

To fix this, hide the internal order of hashes with sort when sending output or running database queries.

(An alternative workaround is PERL_HASH_SEED=0, but this seems nicer.)
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
---
 git-cvsserver.perl | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/git-cvsserver.perl b/git-cvsserver.perl
index 67b1e7b..6177f4a 100755
--- a/git-cvsserver.perl
+++ b/git-cvsserver.perl
@@ -430,10 +430,10 @@ sub req_validrequests
 
     $log->debug("req_validrequests");
 
-    $log->debug("SEND : Valid-requests " . join(" ",keys %$methods));
+    $log->debug("SEND : Valid-requests " . join(" ",sort keys %$methods));
     $log->debug("SEND : ok");
 
-    print "Valid-requests " . join(" ",keys %$methods) . "\n";
+    print "Valid-requests " . join(" ",sort keys %$methods) . "\n";
     print "ok\n";
 }
 
@@ -2124,7 +2124,7 @@ sub req_diff
             print "M retrieving revision $meta2->{revision}\n"
         }
         print "M diff ";
-        foreach my $opt ( keys %{$state->{opt}} )
+        foreach my $opt ( sort keys %{$state->{opt}} )
         {
             if ( ref $state->{opt}{$opt} eq "ARRAY" )
             {
@@ -4050,7 +4050,7 @@ sub update
             close FILELIST;
 
             # Detect deleted files
-            foreach my $file ( keys %$head )
+            foreach my $file ( sort keys %$head )
             {
                 unless ( exists $seen_files->{$file} or $head->{$file}{filehash} eq "deleted" )
                 {
@@ -4078,7 +4078,7 @@ sub update
     }
 
     $self->delete_head();
-    foreach my $file ( keys %$head )
+    foreach my $file ( sort keys %$head )
     {
         $self->insert_head(
             $file,
-- 
1.8.4.1
Next: Junio C Hamano
Message 1 of 2 in “cvsserver: Determinize output to combat Perl 5.18 hash randomization”
  1. cvsserver: Determinize output to combat Perl 5.18 hash randomizationAnders Kaseorg, Oct 30, 2013
  2. Junio C HamanoOct 30, 2013

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