Bug 17356: Add atomic update .perl skeleton file

To show devs how it should be written.

Test plan:
% cp installer/data/mysql/atomicupdate/skeleton.perl
installer/data/mysql/atomicupdate/bug_XXXXX.perl
% perl installer/data/mysql/updatedatabase.pl

You should see:
DEV atomic update: bug_xxxxx.perl
Upgrade to 16.06.00.XXX done (Bug XXXXX - description)

Signed-off-by: Liz Rea <liz@catalyst.net.nz>
Very good. I'll submit a patch for the readme to make the instructions better.

Signed-off-by: Liz Rea <liz@catalyst.net.nz>

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>

installer/data/mysql/atomicupdate/skeleton.perl

@@ -0,0 +1,10 @@
+use C4::Installer;
+my $dbh = C4::Context->dbh;
+$DBversion = '16.06.00.XXX';
+if (C4::Context->preference("Version") < TransformToNum($DBversion)) {
+    unless( column_exists( 'biblio', 'biblionumber' ) ) { # or constraint_exists( $table_name, $key_name )
+        warn "There is something wrong";
+    }
+    SetVersion ($DBversion);
+    print "Upgrade to $DBversion done (Bug XXXXX - description)\n";
+}

installer/data/mysql/updatedatabase.pl

@@ -13585,6 +13585,7 @@ my $update_dir = C4::Context->config('intranetdir') . '/installer/data/mysql/ato
 opendir( my $dirh, $update_dir );
 foreach my $file ( sort readdir $dirh ) {
     next if $file !~ /\.(sql|perl)$/;  #skip other files
+    next if $file eq 'skeleton.perl'; # skip the skeleton file
     print "DEV atomic update: $file\n";
     if ( $file =~ /\.sql$/ ) {
         my $installer = C4::Installer->new();