Merge 'resultsetcolumn_custom_columns' into 'trunk'

r5165@vger:  mendel | 2008-11-16 20:11:42 +0100
 * Merged in changes from 'resultsetcolumn_custom_columns' branch,

diff --cc lib/DBIx/Class/ResultSetColumn.pm
index 68cc4e0,167cd02..7b0fee6
--- 1/lib/DBIx/Class/ResultSetColumn.pm
--- 2/lib/DBIx/Class/ResultSetColumn.pm
+++ b/lib/DBIx/Class/ResultSetColumn.pm
@@@ -36,8 -37,16 +37,19 @@@ sub new 
    my ($class, $rs, $column) = @_;
    $class = ref $class if ref $class;
    my $new_parent_rs = $rs->search_rs; # we don't want to mess up the original, so clone it
-   $new_parent_rs->{attrs}->{prefetch} = undef; # prefetch causes additional columns to be fetched
-   my $new = bless { _column => $column, _parent_resultset => $new_parent_rs }, $class;
+   my $attrs = $new_parent_rs->_resolved_attrs;
+   $new_parent_rs->{attrs}->{$_} = undef for qw(prefetch include_columns +select +as); # prefetch, include_columns, +select, +as cause additional columns to be fetched
+ 
++  # If $column can be found in the 'as' list of the parent resultset, use the
++  # corresponding element of its 'select' list (to keep any custom column
++  # definition set up with 'select' or '+select' attrs), otherwise use $column
++  # (to create a new column definition on-the-fly).
+   my $as_list = $attrs->{as} || [];
+   my $select_list = $attrs->{select} || [];
+   my $as_index = List::Util::first { ($as_list->[$_] || "") eq $column } 0..$#$as_list;
 -
+   my $select = defined $as_index ? $select_list->[$as_index] : $column;
+ 
+   my $new = bless { _select => $select, _as => $column, _parent_resultset => $new_parent_rs }, $class;
    $new->throw_exception("column must be supplied") unless $column;
    return $new;
  }