Add Porting/make_snapshot.pl

Which should have been included with the corresponding MANIFEST change
in the previous commit.

diff --git a/Porting/make_snapshot.pl b/Porting/make_snapshot.pl
new file mode 100755 (executable)
index 0000000..6ff3c93
--- /dev/null
+++ b/Porting/make_snapshot.pl
@@ -0,0 +1,68 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use File::Path;
+use Cwd;
+
+use POSIX qw(strftime);
+sub isotime { strftime "%Y-%m-%d.%H:%M:%S",gmtime(shift||time) }
+
+my ($abbr,$sha1,$tstamp);
+$sha1= shift || "HEAD";
+my $zip_root= $ENV{PERL_SNAPSHOT_ZIP_ROOT} || "/gitcommon/branches/snapshot";
+my $gitdir= shift || `git rev-parse --git-dir`
+    or die "Not a git repo!\n";
+chomp $gitdir;
+my $workdir= $gitdir;
+if ( $workdir =~ s!/\.git\z!! ) {
+    chdir $workdir 
+        or die "Failed to chdir to $workdir\n";
+} else {
+    chdir $workdir
+        or die "Failed to chdir to bare repo $workdir\n";
+}
+
+($sha1, $abbr,$tstamp)= split /\s+/, `git log --pretty='format:%H %h %ct' -1 $sha1`
+    or die "Failed to parse '$sha1'\n";
+chomp($sha1,$abbr,$tstamp);
+
+#die "'$sha1','$abbr'\n";
+
+my $path= join "/", $zip_root, substr($sha1,0,2), substr($sha1,0,4);
+my $tar_file= "$sha1.tar.$$";
+my $gz_file= "$sha1.tgz";
+my $prefix= "perl-$abbr/";
+
+if (!-e "$path/$gz_file") {
+    mkpath $path if !-d $path;
+
+    system("git archive --format=tar --prefix=$prefix $sha1 > $path/$tar_file");
+    my @branches=(
+              'origin/blead',
+              'origin/maint-5.10',
+              'origin/maint-5.8',
+              'origin/maint-5.8-dor',
+              'origin/maint-5.6',
+              'origin/maint-5.005',
+              'origin/maint-5.004',
+    );
+    my $branch;
+    foreach my $b (@branches) {
+        $branch= $b and last 
+            if `git log --pretty='format:%H' $b | grep $sha1`;
+    }
+
+    $branch ||= "unknown-branch";
+    chomp(my $describe= `git describe`);
+    chdir $path;
+    {
+        open my $fh,">","$path/$$.patch" or die "Failed to open $$.patch for writing\n";
+        print $fh join(" ", $branch, $tstamp, $sha1, $describe) . "\n";
+        close $fh;
+    }
+    system("tar -f $tar_file --transform='s,^$$,$prefix,g' --owner=root --group=root --mode=664 --append $$.patch");
+    system("gzip -S .gz -9 $tar_file");
+    rename "$tar_file.gz", "$gz_file";
+}
+print "$path/$gz_file", -t STDOUT ? "\n" :"";
+