From: Matt S Trout <mst@shadowcat.co.uk>
Date: Fri, 20 Apr 2012 03:20:25 +0000 (+0000)
Subject: introduce internal prune_multiplying to de-hack some code
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=d35a4e048a7999e59f66c54a21eb12515e01fd42;p=dbsrgits%2FDBIx-Class-Historic.git

introduce internal prune_multiplying to de-hack some code
---

diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm
index b491e6a..43c06fb 100644
--- a/lib/DBIx/Class/ResultSet.pm
+++ b/lib/DBIx/Class/ResultSet.pm
@@ -1901,7 +1901,7 @@ sub _rs_update_delete {
   # make a new $rs selecting only the PKs (that's all we really need for the subq)
   delete @{$attrs}{qw/collapse select _prefetch_selector_range as/};
   $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
-  #$attrs->{group_by} = [];  # FIXME - this is an evil hack, it causes the optimiser to kick in and throw away the LEFT joins
+  $attrs->{prune_multiplying} = 1;
   my $subrs = (ref $self)->new($rsrc, $attrs);
 
   if (@$idcols == 1) {
diff --git a/lib/DBIx/Class/Storage/DBIHacks.pm b/lib/DBIx/Class/Storage/DBIHacks.pm
index 32c26a0..a5ce102 100644
--- a/lib/DBIx/Class/Storage/DBIHacks.pm
+++ b/lib/DBIx/Class/Storage/DBIHacks.pm
@@ -39,7 +39,8 @@ sub _prune_unused_joins {
 
   # a grouped set will not be affected by amount of rows. Thus any
   # {multiplying} joins can go
-  delete $aliastypes->{multiplying} if $attrs->{group_by};
+  delete $aliastypes->{multiplying}
+    if $attrs->{group_by} or $attrs->{prune_multiplying};
 
   my @newfrom = $from->[0]; # FROM head is always present
 
@@ -115,7 +116,7 @@ sub _adjust_select_args_for_complex_prefetch {
     local $self->{_use_join_optimizer} = 1;
 
     my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, {
-      group_by => ['dummy'], %$inner_attrs,
+      prune_multiplying => 1, %$inner_attrs,
     });
 
     my $inner_aliastypes =