From: Peter Rabbitson <ribasushi@cpan.org>
Date: Thu, 1 Sep 2016 18:22:55 +0000 (+0200)
Subject: Protect several resolve_relationship_condition() callsites
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=e5c6382908ee65577e53c0771629384d70959a3d;p=dbsrgits%2FDBIx-Class.git

Protect several resolve_relationship_condition() callsites

Some external use of DBIx::Class::ParameterizedJoinHack revealed a couple
sites where the relationship resolution may unexpectedly, yet non-fatally
fail. This protects all the reasonable places (partially reverting b47fb9c0),
downgrading the exceptions to once-per-callsite warnings.

I did not have time to dig to find the underlying problem, there may very well
be a real bug lurking around :/

For reproduction of the (now) warnings: see https://github.com/ctrlo/lenio
---

diff --git a/lib/DBIx/Class/Relationship/Base.pm b/lib/DBIx/Class/Relationship/Base.pm
index cfd23f2..ab18bed 100644
--- a/lib/DBIx/Class/Relationship/Base.pm
+++ b/lib/DBIx/Class/Relationship/Base.pm
@@ -8,10 +8,16 @@ use base qw/DBIx::Class/;
 use Scalar::Util qw/weaken blessed/;
 use DBIx::Class::_Util qw(
   UNRESOLVABLE_CONDITION DUMMY_ALIASPAIR
-  dbic_internal_try fail_on_internal_call
+  dbic_internal_try dbic_internal_catch fail_on_internal_call
 );
 use DBIx::Class::SQLMaker::Util 'extract_equality_conditions';
 use DBIx::Class::Carp;
+
+# FIXME - this should go away
+# instead Carp::Skip should export usable keywords or something like that
+my $unique_carper;
+BEGIN { $unique_carper = \&carp_unique }
+
 use namespace::clean;
 
 =head1 NAME
@@ -525,8 +531,7 @@ sub related_resultset {
 
   my $relcond_is_freeform = ref $rel_info->{cond} eq 'CODE';
 
-  my $jfc = $rsrc->_resolve_relationship_condition(
-
+  my $rrc_args = {
     rel_name => $rel,
     self_result_object => $self,
 
@@ -545,8 +550,37 @@ sub related_resultset {
     # out of an existing object, with the new source being at the head
     # of the FROM chain. Having a 'me' alias is nothing but expected there
     foreign_alias => 'me',
+  };
 
-  )->{join_free_condition};
+  my $jfc = (
+    # In certain extraordinary circumstances the relationship resolution may
+    # throw (e.g. when walking through elaborate custom conds)
+    # In case the object is "real" (i.e. in_storage) we just go ahead and
+    # let the exception surface. Otherwise we carp and move on.
+    #
+    # The elaborate code-duplicating ternary is there because the xsified
+    # ->in_storage() is orders of magnitude faster than the Try::Tiny-like
+    # construct below ( perl's low level tooling is truly shit :/ )
+    ( $self->in_storage or DBIx::Class::_Util::in_internal_try )
+      ? $rsrc->_resolve_relationship_condition($rrc_args)->{join_free_condition}
+      : dbic_internal_try {
+          $rsrc->_resolve_relationship_condition($rrc_args)->{join_free_condition}
+        }
+        dbic_internal_catch {
+          $unique_carper->(
+            "Resolution of relationship '$rel' failed unexpectedly, "
+          . 'please relay the following error and seek assistance via '
+          . DBIx::Class::_ENV_::HELP_URL . ". Encountered error: $_"
+          );
+
+          # FIXME - this is questionable
+          # force skipping re-resolution, and instead just return an UC rset
+          $relcond_is_freeform = 0;
+
+          # RV
+          undef;
+        }
+  );
 
   my $rel_rset;
 
diff --git a/lib/DBIx/Class/Relationship/ManyToMany.pm b/lib/DBIx/Class/Relationship/ManyToMany.pm
index e715f10..2812b6b 100644
--- a/lib/DBIx/Class/Relationship/ManyToMany.pm
+++ b/lib/DBIx/Class/Relationship/ManyToMany.pm
@@ -7,9 +7,10 @@ use warnings;
 use DBIx::Class::Carp;
 use DBIx::Class::_Util qw( quote_sub perlstring );
 
-# FIXME - this souldn't be needed
-my $cu;
-BEGIN { $cu = \&carp_unique }
+# FIXME - this should go away
+# instead Carp::Skip should export usable keywords or something like that
+my $unique_carper;
+BEGIN { $unique_carper = \&carp_unique }
 
 use namespace::clean;
 
@@ -82,7 +83,7 @@ EOC
     my @extra_meth_qsub_args = (
       {
         '$rel_attrs' => \{ alias => $f_rel, %{ $rel_attrs||{} } },
-        '$carp_unique' => \$cu,
+        '$carp_unique' => \$unique_carper,
       },
       { attributes => [
         'DBIC_method_is_indirect_sugar',
diff --git a/lib/DBIx/Class/ResultSource/RowParser.pm b/lib/DBIx/Class/ResultSource/RowParser.pm
index 069d331..6540dc7 100644
--- a/lib/DBIx/Class/ResultSource/RowParser.pm
+++ b/lib/DBIx/Class/ResultSource/RowParser.pm
@@ -10,10 +10,15 @@ use DBIx::Class::ResultSource::RowParser::Util qw(
   assemble_simple_parser
   assemble_collapsing_parser
 );
-use DBIx::Class::_Util 'DUMMY_ALIASPAIR';
+use DBIx::Class::_Util qw( DUMMY_ALIASPAIR dbic_internal_try dbic_internal_catch );
 
 use DBIx::Class::Carp;
 
+# FIXME - this should go away
+# instead Carp::Skip should export usable keywords or something like that
+my $unique_carper;
+BEGIN { $unique_carper = \&carp_unique }
+
 use namespace::clean;
 
 # Accepts a prefetch map (one or more relationships for the current source),
@@ -187,13 +192,28 @@ sub _resolve_collapse {
       is_single => ( $inf->{attrs}{accessor} && $inf->{attrs}{accessor} ne 'multi' ),
       is_inner => ( ( $inf->{attrs}{join_type} || '' ) !~ /^left/i),
       rsrc => $self->related_source($rel),
-      fk_map => $self->_resolve_relationship_condition(
-        rel_name => $rel,
+      fk_map => (
+        dbic_internal_try {
+          $self->_resolve_relationship_condition(
+            rel_name => $rel,
+
+            # an API where these are optional would be too cumbersome,
+            # instead always pass in some dummy values
+            DUMMY_ALIASPAIR,
+          )->{identity_map},
+        }
+        dbic_internal_catch {
+
+          $unique_carper->(
+            "Resolution of relationship '$rel' failed unexpectedly, "
+          . 'please relay the following error and seek assistance via '
+          . DBIx::Class::_ENV_::HELP_URL . ". Encountered error: $_"
+          );
 
-        # an API where these are optional would be too cumbersome,
-        # instead always pass in some dummy values
-        DUMMY_ALIASPAIR,
-      )->{identity_map},
+          # RV
+          +{}
+        }
+      ),
     };
   }