Add an extra RV to the relationship resolver

A certain spot in the codebase check whether a relationship is "simple".
This additional flag allows to consider coderef conditions as well, instead
of simply punting with "not a HASH? - no can do"

See next commit for the actual switchover

While at it fix a subtle bug introduced in b5ce674 - originally the helper
is_literal_value recognized -ident as a valid literal. Later on during the
migration into SQLA this logic was lost (I do not exactly recall the details),
yet the DBIC side was never adjusted. All callsites were audited to make sure
nothing else was missed.

lib/DBIx/Class/ResultSource.pm

@@ -19,7 +19,7 @@ use DBIx::Class::Carp;
 use DBIx::Class::_Util qw(
   UNRESOLVABLE_CONDITION
   dbic_internal_try fail_on_internal_call
-  refdesc emit_loud_diag
+  refdesc emit_loud_diag dump_value
 );
 use DBIx::Class::SQLMaker::Util qw( normalize_sqla_condition extract_equality_conditions );
 use DBIx::Class::ResultSource::FromSpec::Util 'fromspec_columns_info';
@@ -2238,6 +2238,7 @@ Internals::SvREADONLY($UNRESOLVABLE_CONDITION => 1);
 ## returns a hash
 # condition           => (a valid *likely fully qualified* sqla cond structure)
 # identity_map        => (a hashref of foreign-to-self *unqualified* column equality names)
+# identity_map_matches_condition => (boolean, indicates whether the entire condition is expressed in the identity-map)
 # join_free_condition => (a valid *fully qualified* sqla cond structure, maybe unset)
 # inferred_values     => (in case of an available join_free condition, this is a hashref of
 #                         *unqualified* column/value *EQUALITY* pairs, representing an amalgamation
@@ -2591,29 +2592,51 @@ sub _resolve_relationship_condition {
       "Unable to complete value inferrence - $exception_rel_id results in expression(s) instead of definitive values: %s",
       do {
         # FIXME - used for diag only, but still icky
-        my $sqlm = $self->schema->storage->sql_maker;
+        my $sqlm =
+          dbic_internal_try { $self->schema->storage->sql_maker }
+            ||
+          (
+            require DBIx::Class::SQLMaker
+              and
+            DBIx::Class::SQLMaker->new
+          )
+        ;
         local $sqlm->{quote_char};
         local $sqlm->{_dequalify_idents} = 1;
         ($sqlm->_recurse_where({ -and => \@nonvalues }))[0]
       }
     )) if @nonvalues;
 
-
     $ret->{inferred_values} ||= {};
 
     $ret->{inferred_values}{$_} = $args->{infer_values_based_on}{$_}
       for keys %{$args->{infer_values_based_on}};
   }
 
+  my $identity_map_incomplete;
+
   # add the identities based on the main condition
   # (may already be there, since easy to calculate on the fly in the HASH case)
   if ( ! $ret->{identity_map} ) {
 
     my $col_eqs = extract_equality_conditions($ret->{condition});
 
+    $identity_map_incomplete++ if (
+      $ret->{condition} eq UNRESOLVABLE_CONDITION
+        or
+      (
+        keys %{$ret->{condition}}
+          !=
+        keys %$col_eqs
+      )
+    );
+
     my $colinfos;
     for my $lhs (keys %$col_eqs) {
 
+      # start with the assumption it won't work
+      $identity_map_incomplete++;
+
       next if $col_eqs->{$lhs} eq UNRESOLVABLE_CONDITION;
 
       # there is no way to know who is right and who is left in a cref
@@ -2626,8 +2649,17 @@ sub _resolve_relationship_condition {
 
       next unless $colinfos->{$lhs};  # someone is engaging in witchcraft
 
-      if ( my $rhs_ref = is_literal_value( $col_eqs->{$lhs} ) ) {
-
+      if( my $rhs_ref =
+        (
+          ref $col_eqs->{$lhs} eq 'HASH'
+            and
+          keys %{$col_eqs->{$lhs}} == 1
+            and
+          exists $col_eqs->{$lhs}{-ident}
+        )
+          ? [ $col_eqs->{$lhs}{-ident} ]  # repack to match the RV of is_literal_value
+          : is_literal_value( $col_eqs->{$lhs} )
+      ) {
         if (
           $colinfos->{$rhs_ref->[0]}
             and
@@ -2637,6 +2669,9 @@ sub _resolve_relationship_condition {
             ? ( $ret->{identity_map}{$colinfos->{$lhs}{-colname}} = $colinfos->{$rhs_ref->[0]}{-colname} )
             : ( $ret->{identity_map}{$colinfos->{$rhs_ref->[0]}{-colname}} = $colinfos->{$lhs}{-colname} )
           ;
+
+          # well, what do you know!
+          $identity_map_incomplete--;
         }
       }
       elsif (
@@ -2656,6 +2691,10 @@ sub _resolve_relationship_condition {
     }
   }
 
+  $ret->{identity_map_matches_condition} = ($identity_map_incomplete ? 0 : 1)
+    if $ret->{identity_map};
+
+
   # FIXME - temporary, to fool the idiotic check in SQLMaker::_join_condition
   $ret->{condition} = { -and => [ $ret->{condition} ] } unless (
     $ret->{condition} eq UNRESOLVABLE_CONDITION
@@ -2667,6 +2706,50 @@ sub _resolve_relationship_condition {
     )
   );
 
+
+  if( DBIx::Class::_ENV_::ASSERT_NO_INCONSISTENT_RELATIONSHIP_RESOLUTION ) {
+
+    my $sqlm =
+      dbic_internal_try { $self->schema->storage->sql_maker }
+        ||
+      (
+        require DBIx::Class::SQLMaker
+          and
+        DBIx::Class::SQLMaker->new
+      )
+    ;
+
+    local $sqlm->{_dequalify_idents} = 1;
+
+    my ($cond_as_sql, $identmap_as_sql) = map
+      { join ' : ', map { defined $_ ? $_ : '{UNDEF}' } $sqlm->_recurse_where($_) }
+      (
+        $ret->{condition},
+
+        { map {
+          # inverse because of how the idmap is declared
+          $ret->{identity_map}{$_} => { -ident => $_ }
+        } keys %{$ret->{identity_map}} },
+      )
+    ;
+
+    emit_loud_diag(
+      confess => 1,
+      msg => sprintf (
+        "Resolution of %s produced inconsistent metadata:\n\n"
+      . "returned value of 'identity_map_matches_condition':    %s\n"
+      . "returned 'condition' rendered as de-qualified SQL:     %s\n"
+      . "returned 'identity_map' rendered as de-qualified SQL:  %s\n\n"
+      . "The condition declared on the misclassified relationship is: %s ",
+        $exception_rel_id,
+        ( $ret->{identity_map_matches_condition} || 0 ),
+        $cond_as_sql,
+        $identmap_as_sql,
+        dump_value( $rel_info->{cond} ),
+      ),
+    ) if ( $ret->{identity_map_matches_condition} xor ( $cond_as_sql eq $identmap_as_sql ) );
+  }
+
   $ret;
 }
 

lib/DBIx/Class/SQLMaker.pm

@@ -191,7 +191,7 @@ sub _assert_bindval_matches_bindtype () { 1 };
 
 # poor man's de-qualifier
 sub _quote {
-  $_[0]->next::method( ( $_[0]{_dequalify_idents} and ! ref $_[1] )
+  $_[0]->next::method( ( $_[0]{_dequalify_idents} and defined $_[1] and ! ref $_[1] )
     ? $_[1] =~ / ([^\.]+) $ /x
     : $_[1]
   );

lib/DBIx/Class/_Util.pm

@@ -52,6 +52,7 @@ BEGIN {
         DBIC_ASSERT_NO_INTERNAL_INDIRECT_CALLS
         DBIC_ASSERT_NO_ERRONEOUS_METAINSTANCE_USE
         DBIC_ASSERT_NO_FAILING_SANITY_CHECKS
+        DBIC_ASSERT_NO_INCONSISTENT_RELATIONSHIP_RESOLUTION
         DBIC_STRESSTEST_UTF8_UPGRADE_GENERATED_COLLAPSER_SOURCE
         DBIC_STRESSTEST_COLUMN_INFO_UNAWARE_STORAGE
       )