made search_rs smarter about when to preserve the cache to fix mm prefetch usage

diff --git a/Changes b/Changes
index 3832053..870de96 100644 (file)
--- a/Changes
+++ b/Changes
@@ -1,5 +1,7 @@
 Revision history for DBIx::Class
 
+        - Made search_rs smarter about when to preserve the cache to fix
+          mm prefetch usage
         - Added Storage::DBI subclass for MSSQL over ODBC. 
         - Added freeze, thaw and dclone methods to Schema so that thawed
           objects will get re-attached to the schema.

diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm
index 25d8b03..c2b045c 100644 (file)
--- a/lib/DBIx/Class/ResultSet.pm
+++ b/lib/DBIx/Class/ResultSet.pm
@@ -11,6 +11,7 @@ use Data::Page;
 use Storable;
 use DBIx::Class::ResultSetColumn;
 use DBIx::Class::ResultSourceHandle;
+use List::Util ();
 use base qw/DBIx::Class/;
 
 __PACKAGE__->mk_group_accessors('simple' => qw/result_class _source_handle/);
@@ -168,18 +169,26 @@ always return a resultset, even in list context.
 sub search_rs {
   my $self = shift;
 
-  my $rows;
-
-  unless (@_) {                 # no search, effectively just a clone
-    $rows = $self->get_cache;
-  }
-
   my $attrs = {};
   $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
   my $our_attrs = { %{$self->{attrs}} };
   my $having = delete $our_attrs->{having};
   my $where = delete $our_attrs->{where};
 
+  my $rows;
+
+  my %safe = (alias => 1, cache => 1);
+
+  unless (
+    (@_ && defined($_[0])) # @_ == () or (undef)
+    || 
+    (keys %$attrs # empty attrs or only 'safe' attrs
+    && List::Util::first { !$safe{$_} } keys %$attrs)
+  ) {
+    # no search, effectively just a clone
+    $rows = $self->get_cache;
+  }
+
   my $new_attrs = { %{$our_attrs}, %{$attrs} };
 
   # merge new attrs into inherited

diff --git a/t/76joins.t b/t/76joins.t
index 92e5785..101d71f 100644 (file)
--- a/t/76joins.t
+++ b/t/76joins.t
@@ -247,11 +247,7 @@ $cd = $schema->resultset('CD')->find(1, { prefetch => { cd_to_producer => 'produ
 
 is($cd->producers->first->name, 'Matt S Trout', 'many_to_many accessor ok');
 
-TODO: {
-  local $TODO = 'use prefetched values for many_to_many accessor';
-
-  is($queries, 1, 'many_to_many accessor with nested prefetch ran exactly 1 query');
-}
+is($queries, 1, 'many_to_many accessor with nested prefetch ran exactly 1 query');
 
 $queries = 0;