Final backup fixes

- Dump postgres with --no-owner and use conversion only
- Execute postgres converter only when using mysql
- Use gzip instead of zcat as more portable way to cat gziped file

lib/backup/database.rb

@@ -33,7 +33,7 @@ module Backup
       when "postgresql" then
         $progress.print "Dumping PostgreSQL database #{config['database']} ... "
         pg_env
-        spawn('pg_dump', '--clean', *TABLES.map { |t| "--table=#{t}" }, config['database'], out: compress_wr)
+        spawn('pg_dump', '--no-owner', '--clean', *TABLES.map { |t| "--table=#{t}" }, config['database'], out: compress_wr)
       end
       compress_wr.close
@@ -41,7 +41,10 @@ module Backup
       report_success(success)
       abort 'Backup failed' unless success
-      convert_to_postgresql if mysql_to_postgresql
+
+      if mysql_to_postgresql && config["adapter"] =~ /^mysql/
+        convert_to_postgresql
+      end
     end
     def convert_to_postgresql

lib/support/mysql-postgresql-converter/splice_drop_indexes

@@ -15,7 +15,7 @@ if [ -z "$db_gz" ] || [ -z "$drop_indexes_sql" ] ; then
 fi
 # Capture all text up to the first occurence of 'SET CONSTRAINTS'
-preamble=$(zcat "$db_gz" | sed '/SET CONSTRAINTS/q')
+preamble=$(gzip -cd "$db_gz" | sed '/SET CONSTRAINTS/q')
 if [ -z "$preamble" ] ; then
   fail "Could not read preamble"
 fi
@@ -34,4 +34,4 @@ EOF
 # Print the rest of database.sql.gz. I don't understand this awk script but it
 # prints all lines after the first match of 'SET CONSTRAINTS'.
-zcat "$db_gz" | awk 'f; /SET CONSTRAINTS/ { f = 1 }'
+gzip -cd "$db_gz" | awk 'f; /SET CONSTRAINTS/ { f = 1 }'