Merge 'prefetch' into 'trunk'

diff --combined t/prefetch/rows_bug.t
index d7ec720,821c84e..8683b16
--- 1/t/98rows_prefetch.t
--- 2/t/prefetch/rows_bug.t
+++ b/t/prefetch/rows_bug.t
@@@ -10,7 -10,6 +10,6 @@@ use DBICTest
  plan $@ ? (skip_all => 'needs DBD::SQLite for testing') : (tests => 2);
  
  my $schema = DBICTest->init_schema();
- $schema->storage->debug(1);
  my $no_prefetch = $schema->resultset('Artist')->search(
    undef,
    { rows => 3 }
@@@ -41,26 -40,6 +40,26 @@@ TODO: 
      . " \$use_prefetch_count == $use_prefetch_count)"
    );
  }
 +__END__
 +my $rs1 = $schema->resultset('Artist')->search(
 +    undef, {
 +#        join => 'cds',
 +    },
 +);
 +warn ${$rs1->as_query}->[0], $/;
 +{ my @x = $rs1->all; warn "$#x\n"; }
 +
 +my $rs2 = $schema->resultset('Artist')->search(
 +    undef, {
 +        from => [{
 +            me => $rs1->as_query,
 +        }],
 +        prefetch => 'cds',
 +    },
 +);
 +
 +warn ${$rs2->as_query}->[0], $/;
 +{ my @x = $rs2->all; warn "$#x\n"; }
  
  __END__
  The fix is to, when using prefetch, take the query and put it into a subquery
@@@ -99,6 -78,3 +98,6 @@@ becomes
  Problem:
    * The prefetch->join change needs to happen ONLY IF there are conditions
      that depend on bar being joined.
 +  * How will this work when the $rs is further searched on? Those clauses
 +    need to be added to the subquery, not the outer one. This is particularly
 +    true if rows is added in the attribute later per the Pager.