From 91f1d2324c3aca88432689deeacbe46d6d23c4df Mon Sep 17 00:00:00 2001
From: Andrew McMillan <debian@mcmillan.net.nz>
Date: Mon, 3 Dec 2007 22:28:44 +1300
Subject: [PATCH] Enhance the database patch script to allow for alternative
 patches.

---
 dba/update-rscds-database | 28 ++++++++++++++++++++++------
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/dba/update-rscds-database b/dba/update-rscds-database
index ee192ca6..ec73cd78 100755
--- a/dba/update-rscds-database
+++ b/dba/update-rscds-database
@@ -12,7 +12,7 @@ use Getopt::Long qw(:config permute);  # allow mixed args.
 
 # Options variables
 my $debug  = 0;
-my $dbname = "rscds";
+my $dbname = "davical";
 my $dbport = 5432;
 my $dbuser = "";
 my $dbpass = "";
@@ -46,10 +46,10 @@ my $current_revision = get_current_revision();
 printf( "The database is currently at revision %d.%d.%d.\n", $current_revision->{'schema_major'}, $current_revision->{'schema_minor'}, $current_revision->{'schema_patch'} );
 
 opendir( PATCHDIR, $patchdir ) or die "Can't open patch directory $patchdir";
-my @patches = grep { /^([0-9]+)\.([0-9]+)\.([0-9]+)\.sql$/ } readdir(PATCHDIR);
+my @patches = grep { /^([0-9]+)\.([0-9]+)\.([0-9]+)([a-z]?)\.sql$/ } readdir(PATCHDIR);
 closedir(PATCHDIR);
 
-@patches = sort { compare_revisions(revision_hash($a),revision_hash($b)); } @patches;
+@patches = sort { compare_revisions(revision_hash($a),revision_hash($b), 1); } @patches;
 
 my $applied = 0;
 
@@ -57,7 +57,14 @@ for ( my $i=0; $i <= $#patches;  $i++ ) {
   printf( "Looking at patches[%d] (%s)\n", $i, $patches[$i]) if ( $debug );
   if ( compare_revisions(revision_hash($patches[$i]),$current_revision) > 0 ) {
     print "Applying patch $patches[$i]\n";
-    last unless( apply_patch( $patches[$i] ) );
+    if ( !apply_patch( $patches[$i] ) ) {
+      # Skip to the end unless the next patch is an alternate for the same version.
+      last unless ( compare_revisions(revision_hash($patches[$i]),revision_hash($patches[$i+1])) == 0 );
+      print "Patch failed, but alternatives exist.  Attempting next alternative.\n";
+    }
+    else {
+      print "Patch succeeded.\n";
+    }
     $applied++;
   }
   else {
@@ -91,17 +98,20 @@ exit 0;
 # which is of the form "1.2.3" or we have three parameters.
 ############################################################
 sub revision_hash {
-  my $rev = +{};
+  my $rev = +{ 'schema_major', => 0, 'schema_minor' => 0, 'schema_patch' => 0, 'alternative' => '0' };
   my $first = shift;
-  if ( $first =~ /^([0-9]+)\.([0-9]+)\.([0-9]+)([^0-9]|$)/ ) {
+  return $rev unless ( defined($first) );
+  if ( $first =~ /^([0-9]+)\.([0-9]+)\.([0-9]+)([a-z]?)([^0-9]|$)/ ) {
     $rev->{'schema_major'} = $1;
     $rev->{'schema_minor'} = $2;
     $rev->{'schema_patch'} = $3;
+    $rev->{'alternative'} = $4;
   }
   else {
     $rev->{'schema_major'} = $first;
     $rev->{'schema_minor'} = shift;
     $rev->{'schema_patch'} = shift;
+    $rev->{'alternative'} = '0';
   }
   return $rev;
 }
@@ -113,6 +123,7 @@ sub revision_hash {
 sub compare_revisions {
   my $a = shift;
   my $b = shift;
+  my $test_alt = shift;
 
   return -1 if ( $a->{'schema_major'} < $b->{'schema_major'} );
   return  1 if ( $a->{'schema_major'} > $b->{'schema_major'} );
@@ -123,6 +134,11 @@ sub compare_revisions {
   return -1 if ( $a->{'schema_patch'} < $b->{'schema_patch'} );
   return  1 if ( $a->{'schema_patch'} > $b->{'schema_patch'} );
 
+  if ( defined($test_alt) ) {
+    return -1 if ( $a->{'alternative'} lt $b->{'alternative'} );
+    return  1 if ( $a->{'alternative'} gt $b->{'alternative'} );
+  }
+
   return 0;
 
 }