X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=t%2Fresultset%2Frowparser_internals.t;h=67215eb0976dd58974490ce79150824327f80d43;hb=e10d9d292bb2b14a31b45f36bd25b6610bd2e71d;hp=5bcf939986a2f57721135c540850644b1af5f651;hpb=4e9fc3f33df616fb7340d05e304ff985b9cce9cb;p=dbsrgits%2FDBIx-Class.git

diff --git a/t/resultset/rowparser_internals.t b/t/resultset/rowparser_internals.t
index 5bcf939..67215eb 100644
--- a/t/resultset/rowparser_internals.t
+++ b/t/resultset/rowparser_internals.t
@@ -1,102 +1,232 @@
+BEGIN { do "./t/lib/ANFANG.pm" or die ( $@ || $! ) }
+
 use strict;
 use warnings;
 
 use Test::More;
-use lib qw(t/lib);
+
 use DBICTest;
 use B::Deparse;
+use DBIx::Class::_Util 'perlstring';
 
 my $schema = DBICTest->init_schema(no_deploy => 1);
-my $infmap = [qw/single_track.cd.artist.name year/];
+my $infmap = [qw/
+  single_track.cd.artist.name
+  year
+/];
 
 is_same_src (
-  $schema->source ('CD')->_mk_row_parser({
+  ($schema->source ('CD')->_mk_row_parser({
     inflate_map => $infmap,
-  }),
+  }))[0],
   '$_ = [
     { year => $_->[1] },
-    { single_track => [
-      undef,
-      { cd => [
+    { single_track => ( ! defined( $_->[0]) )
+      ? bless( [
         undef,
-        { artist => [
-          { name  => $_->[0] },
+        { cd => [
+          undef,
+          { artist => [
+            { name  => $_->[0] },
+          ] },
         ] },
-      ]},
-    ]},
+      ], __NBC__ )
+      : [
+        undef,
+        { cd => [
+          undef,
+          { artist => [
+            { name  => $_->[0] },
+          ] },
+        ] },
+      ]
+    },
   ] for @{$_[0]}',
   'Simple 1:1 descending non-collapsing parser',
 );
 
 $infmap = [qw/
+  single_track.cd.artist.cds.tracks.title
   single_track.cd.artist.artistid
   year
-  single_track.cd.artist.cds.tracks.title
   single_track.cd.artist.cds.cdid
   title
   artist
 /];
+
 is_same_src (
-  $schema->source ('CD')->_mk_row_parser({
+  ($schema->source ('CD')->_mk_row_parser({
     inflate_map => $infmap,
-  }),
+  }))[0],
   '$_ = [
-    { artist => $_->[5], title => $_->[4], year => $_->[1] },
-    { single_track => [
-      undef,
-      { cd => [
-        undef,
-        { artist => [
-          { artistid => $_->[0] },
-          { cds => [
-            { cdid => $_->[3] },
-            { tracks => [
-              { title => $_->[2] }
-            ] },
-          ] },
-        ] },
-      ] },
-    ] },
+    { artist => $_->[5], title => $_->[4], year => $_->[2] },
+    {
+      single_track => ( (! defined $_->[0] ) && (! defined $_->[1]) && (! defined $_->[3] ) )
+        ? bless( [
+          undef,
+          {
+            cd => [
+              undef,
+              {
+                artist => [
+                  { artistid => $_->[1] },
+                  {
+                    cds => ( (! defined $_->[0] ) && ( ! defined $_->[3] ) )
+                      ? bless ([
+                        { cdid => $_->[3] },
+                        {
+                          tracks => ( ! defined $_->[0] )
+                            ? bless ( [{ title => $_->[0] }], __NBC__ )
+                            : [{ title => $_->[0] }]
+                        }
+                      ], __NBC__)
+                      : [
+                        { cdid => $_->[3] },
+                        {
+                          tracks => ( ! defined $_->[0] )
+                            ? bless ( [{ title => $_->[0] }], __NBC__ )
+                            : [{ title => $_->[0] }]
+                        }
+                      ]
+                  }
+                ]
+              }
+            ]
+          }
+        ], __NBC__)
+        : [
+          undef,
+          {
+            cd => [
+              undef,
+              {
+                artist => [
+                  { artistid => $_->[1] },
+                  {
+                    cds => ( (! defined $_->[0] ) && ( ! defined $_->[3] ) )
+                      ? bless ([
+                        { cdid => $_->[3] },
+                        {
+                          tracks => ( ! defined $_->[0] )
+                            ? bless ( [{ title => $_->[0] }], __NBC__ )
+                            : [{ title => $_->[0] }]
+                        }
+                      ], __NBC__)
+                      : [
+                        { cdid => $_->[3] },
+                        {
+                          tracks => ( ! defined $_->[0] )
+                            ? bless ( [{ title => $_->[0] }], __NBC__ )
+                            : [{ title => $_->[0] }]
+                        }
+                      ]
+                  }
+                ]
+              }
+            ]
+          }
+        ]
+    }
   ] for @{$_[0]}',
   '1:1 descending non-collapsing parser terminating with chained 1:M:M',
 );
 
+is_same_src (
+  ($schema->source ('CD')->_mk_row_parser({
+    prune_null_branches => 1,
+    inflate_map => $infmap,
+  }))[0],
+  '$_ = [
+    { artist => $_->[5], title => $_->[4], year => $_->[2] },
+    {
+      single_track => ( (! defined $_->[0] ) && (! defined $_->[1]) && (! defined $_->[3] ) ) ? undef : [
+        undef,
+        {
+          cd => [
+            undef,
+            {
+              artist => [
+                { artistid => $_->[1] },
+                {
+                  cds => ( (! defined $_->[0] ) && ( ! defined $_->[3] ) ) ? undef : [
+                    { cdid => $_->[3] },
+                    {
+                      tracks => ( ! defined $_->[0] ) ? undef : [
+                        { title => $_->[0] },
+                      ]
+                    }
+                  ]
+                }
+              ]
+            }
+          ]
+        }
+      ]
+    }
+  ] for @{$_[0]}',
+  '1:1 descending non-collapsing pruning parser terminating with chained 1:M:M',
+);
+
+is_same_src (
+  ($schema->source ('CD')->_mk_row_parser({
+    hri_style => 1,
+    prune_null_branches => 1,
+    inflate_map => $infmap,
+  }))[0],
+  '$_ = {
+      artist => $_->[5], title => $_->[4], year => $_->[2],
+
+      ( single_track => ( (! defined $_->[0] ) && (! defined $_->[1]) && (! defined $_->[3] ) )
+        ? undef
+        : {
+            cd =>
+              {
+                artist => {
+                    artistid => $_->[1],
+                    ( cds => ( (! defined $_->[0] ) && ( ! defined $_->[3] ) )
+                      ? undef
+                      : {
+                          cdid => $_->[3],
+                          ( tracks => ( ! defined $_->[0] )
+                            ? undef
+                            : { title => $_->[0] }
+                          )
+                        }
+                    )
+                  }
+              }
+          }
+      )
+    } for @{$_[0]}',
+  '1:1 descending non-collapsing HRI-direct parser terminating with chained 1:M:M',
+);
+
+
+
 is_deeply (
-  $schema->source('CD')->_resolve_collapse({map { $infmap->[$_] => $_ } 0 .. $#$infmap}),
+  ($schema->source('CD')->_resolve_collapse({ as => {map { $infmap->[$_] => $_ } 0 .. $#$infmap} })),
   {
-    -node_index => 1,
-    -node_id => [ 4, 5 ],
-    -branch_id => [ 0, 2, 3, 4, 5 ],
+    -identifying_columns => [ 4, 5 ],
 
     single_track => {
-      -node_index => 2,
-      -node_id => [ 4, 5],
-      -branch_id => [ 0, 2, 3, 4, 5],
+      -identifying_columns => [ 1, 4, 5 ],
       -is_optional => 1,
       -is_single => 1,
 
       cd => {
-        -node_index => 3,
-        -node_id => [ 4, 5 ],
-        -branch_id => [ 0, 2, 3, 4, 5 ],
+        -identifying_columns => [ 1, 4, 5 ],
         -is_single => 1,
 
         artist => {
-          -node_index => 4,
-          -node_id => [ 0 ],
-          -branch_id => [ 0, 2, 3 ],
+          -identifying_columns => [ 1, 4, 5 ],
           -is_single => 1,
 
           cds => {
-            -node_index => 5,
-            -node_id => [ 3 ],
-            -branch_id => [ 2, 3 ],
+            -identifying_columns => [ 1, 3, 4, 5 ],
             -is_optional => 1,
 
             tracks => {
-              -node_index => 6,
-              -node_id => [ 2, 3 ],
-              -branch_id => [ 2, 3 ],
+              -identifying_columns => [ 0, 1, 3, 4, 5 ],
               -is_optional => 1,
             },
           },
@@ -108,48 +238,219 @@ is_deeply (
 );
 
 is_same_src (
-  $schema->source ('CD')->_mk_row_parser({
+  ($schema->source ('CD')->_mk_row_parser({
     inflate_map => $infmap,
     collapse => 1,
-  }),
-  ' my($rows_pos, $result_pos, $cur_row, @cur_row_ids, @collapse_idx, $is_new_res) = (0, 0);
+  }))[0],
+  ' my $rows_pos = 0;
+    my ($result_pos, @collapse_idx, $cur_row_data, %cur_row_ids);
 
-    while ($cur_row = (
-      ( $rows_pos >= 0 and $_[0][$rows_pos++] ) or do { $rows_pos = -1; undef } )
-        ||
+    while ($cur_row_data = (
+      (
+        $rows_pos >= 0
+          and
+        (
+          $_[0][$rows_pos++]
+            or
+          ( ($rows_pos = -1), undef )
+        )
+      )
+        or
       ( $_[1] and $_[1]->() )
-    ) {
+    ) ) {
 
-      $cur_row_ids[$_] = defined $cur_row->[$_] ? $cur_row->[$_] : "\xFF\xFFN\xFFU\xFFL\xFFL\xFF\xFF"
-        for (0, 2, 3, 4, 5);
 
-      # a present cref implies lazy prefetch, implies a supplied stash in $_[2]
-      $_[1] and $result_pos and unshift(@{$_[2]}, $cur_row) and last
-        if $is_new_res = ! $collapse_idx[1]{$cur_row_ids[4]}{$cur_row_ids[5]};
+      # NULL checks
+      # mandatory => { 4 => 1, 5 => 1 }
+      # from_first_encounter => [ [ 1, 3, 0 ] ]
+      #
+      ( defined( $cur_row_data->[4] ) or $_[3]->{4} = 1 ),
 
-      $collapse_idx[1]{$cur_row_ids[4]}{$cur_row_ids[5]} ||= [{ artist => $cur_row->[5], title => $cur_row->[4], year => $cur_row->[1] }];
-      $collapse_idx[1]{$cur_row_ids[4]}{$cur_row_ids[5]}[1]{single_track} ||= $collapse_idx[2]{$cur_row_ids[4]}{$cur_row_ids[5]};
-      $collapse_idx[2]{$cur_row_ids[4]}{$cur_row_ids[5]}[1]{cd} ||= $collapse_idx[3]{$cur_row_ids[4]}{$cur_row_ids[5]};
-      $collapse_idx[3]{$cur_row_ids[4]}{$cur_row_ids[5]}[1]{artist} ||= $collapse_idx[4]{$cur_row_ids[0]} ||= [{ artistid => $cur_row->[0] }];
+      ( defined( $cur_row_data->[5] ) or $_[3]->{5} = 1 ),
 
-      $collapse_idx[4]{$cur_row_ids[0]}[1]{cds} ||= [];
-      push @{$collapse_idx[4]{$cur_row_ids[0]}[1]{cds}}, $collapse_idx[5]{$cur_row_ids[3]} ||= [{ cdid => $cur_row->[3] }]
-        unless $collapse_idx[5]{$cur_row_ids[3]};
+      (
+        ( not defined $cur_row_data->[1] )
+        ? (
+            ( not defined $cur_row_data->[3] )
+              and
+            ( not defined $cur_row_data->[0] )
+              or
+            ( $_[3]->{1} = 1 )
+          )
+      : ( not defined $cur_row_data->[3] )
+        ? (
+            ( not defined $cur_row_data->[0] )
+              or
+            ( $_[3]->{3} = 1 )
+        )
+      : ()
+      ),
 
-      $collapse_idx[5]{$cur_row_ids[3]}[1]{tracks} ||= [];
-      push @{$collapse_idx[5]{$cur_row_ids[3]}[1]{tracks}}, $collapse_idx[6]{$cur_row_ids[2]}{$cur_row_ids[3]} ||= [{ title => $cur_row->[2] }]
-        unless $collapse_idx[6]{$cur_row_ids[2]}{$cur_row_ids[3]};
+      ( keys %{$_[3]} and (
+        ( @{$_[2]} = $cur_row_data ),
+        ( $result_pos = 0 ),
+        last
+      ) ),
+
+
+      ( @cur_row_ids{0,1,3,4,5} = (
+        ( $cur_row_data->[0] // "\0NULL\xFF$rows_pos\xFF0\0" ),
+        ( $cur_row_data->[1] // "\0NULL\xFF$rows_pos\xFF1\0" ),
+        ( $cur_row_data->[3] // "\0NULL\xFF$rows_pos\xFF3\0" ),
+        ( $cur_row_data->[4] ),
+        ( $cur_row_data->[5] ),
+      ) ),
+
+      # a present cref in $_[1] implies lazy prefetch, implies a supplied stash in $_[2]
+      ( $_[1] and $result_pos and ! $collapse_idx[0]{$cur_row_ids{4}}{$cur_row_ids{5}} and (unshift @{$_[2]}, $cur_row_data) and last ),
+
+      # the rowdata itself for root node
+      ( $collapse_idx[0]{$cur_row_ids{4}}{$cur_row_ids{5}} //= $_[0][$result_pos++] = [{ artist => $cur_row_data->[5], title => $cur_row_data->[4], year => $cur_row_data->[2] }] ),
+
+      # prefetch data of single_track (placed in root)
+      ( $collapse_idx[0]{$cur_row_ids{4}}{$cur_row_ids{5}}[1]{single_track} //= $collapse_idx[1]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}} = [] ),
+      ( defined($cur_row_data->[1]) or bless( $collapse_idx[0]{$cur_row_ids{4}}{$cur_row_ids{5}}[1]{single_track}, __NBC__ ) ),
+
+      # prefetch data of cd (placed in single_track)
+      ( $collapse_idx[1]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}}[1]{cd} //= $collapse_idx[2]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}} = [] ),
+
+      # prefetch data of artist ( placed in single_track->cd)
+      ( $collapse_idx[2]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}}[1]{artist} //= $collapse_idx[3]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}} = [{ artistid => $cur_row_data->[1] }] ),
+
+      # prefetch data of cds (if available)
+      (
+        (! $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{3}}{$cur_row_ids{4}}{$cur_row_ids{5}} )
+          and
+        push @{$collapse_idx[3]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}}[1]{cds}}, (
+          $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{3}}{$cur_row_ids{4}}{$cur_row_ids{5}} = [{ cdid => $cur_row_data->[3] }]
+        )
+      ),
+      ( defined($cur_row_data->[3]) or bless( $collapse_idx[3]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}}[1]{cds}, __NBC__ ) ),
+
+      # prefetch data of tracks (if available)
+      (
+        (! $collapse_idx[5]{$cur_row_ids{0}}{$cur_row_ids{1}}{$cur_row_ids{3}}{$cur_row_ids{4}}{$cur_row_ids{5}} )
+          and
+        push @{$collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{3}}{$cur_row_ids{4}}{$cur_row_ids{5}}[1]{tracks}}, (
+          $collapse_idx[5]{$cur_row_ids{0}}{$cur_row_ids{1}}{$cur_row_ids{3}}{$cur_row_ids{4}}{$cur_row_ids{5}} = [{ title => $cur_row_data->[0] }]
+        )
+      ),
+      ( defined($cur_row_data->[0]) or bless( $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{3}}{$cur_row_ids{4}}{$cur_row_ids{5}}[1]{tracks}, __NBC__ ) ),
 
-      $_[0][$result_pos++] = $collapse_idx[1]{$cur_row_ids[4]}{$cur_row_ids[5]}
-        if $is_new_res;
     }
-    splice @{$_[0]}, $result_pos;
+    $#{$_[0]} = $result_pos - 1;
   ',
   'Same 1:1 descending terminating with chained 1:M:M but with collapse',
 );
 
+is_same_src (
+  ($schema->source ('CD')->_mk_row_parser({
+    inflate_map => $infmap,
+    collapse => 1,
+    hri_style => 1,
+    prune_null_branches => 1,
+  }))[0],
+  ' my $rows_pos = 0;
+    my ($result_pos, @collapse_idx, $cur_row_data, %cur_row_ids);
+
+    while ($cur_row_data = (
+      (
+        $rows_pos >= 0
+          and
+        (
+          $_[0][$rows_pos++]
+            or
+          ( ($rows_pos = -1), undef )
+        )
+      )
+        or
+      ( $_[1] and $_[1]->() )
+    ) ) {
+
+
+      # NULL checks
+      # mandatory => { 4 => 1, 5 => 1 }
+      # from_first_encounter => [ [ 1, 3, 0 ] ]
+      #
+      ( defined( $cur_row_data->[4] ) or $_[3]->{4} = 1 ),
+
+      ( defined( $cur_row_data->[5] ) or $_[3]->{5} = 1 ),
+
+      (
+        ( not defined $cur_row_data->[1] )
+        ? (
+          ( not defined $cur_row_data->[3] )
+            and
+          ( not defined $cur_row_data->[0] )
+            or
+          ( $_[3]->{1} = 1 )
+        )
+      : ( not defined $cur_row_data->[3] )
+        ? (
+          ( not defined $cur_row_data->[0] )
+            or
+          ( $_[3]->{3} = 1 )
+        )
+      : ()
+      ),
+
+      ( keys %{$_[3]} and (
+        ( @{$_[2]} = $cur_row_data ),
+        ( $result_pos = 0 ),
+        last
+      ) ),
+
+
+      ( @cur_row_ids{0, 1, 3, 4, 5} = @{$cur_row_data}[0, 1, 3, 4, 5] ),
+
+      # a present cref in $_[1] implies lazy prefetch, implies a supplied stash in $_[2]
+      ( $_[1] and $result_pos and ! $collapse_idx[0]{$cur_row_ids{4}}{$cur_row_ids{5}} and (unshift @{$_[2]}, $cur_row_data) and last ),
+
+      # the rowdata itself for root node
+      ( $collapse_idx[0]{$cur_row_ids{4}}{$cur_row_ids{5}} //= $_[0][$result_pos++] = { artist => $cur_row_data->[5], title => $cur_row_data->[4], year => $cur_row_data->[2] } ),
+
+      # prefetch data of single_track (placed in root)
+      ( (! defined($cur_row_data->[1]) ) ? $collapse_idx[0]{$cur_row_ids{4}}{$cur_row_ids{5}}{single_track} = undef : do {
+        ( $collapse_idx[0]{$cur_row_ids{4}}{$cur_row_ids{5}}{single_track} //= $collapse_idx[1]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}} = {} ),
+
+        # prefetch data of cd (placed in single_track)
+        ( $collapse_idx[1]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}}{cd} //= $collapse_idx[2]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}} = {} ),
+
+        # prefetch data of artist ( placed in single_track->cd)
+        ( $collapse_idx[2]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}}{artist} //= $collapse_idx[3]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}} = { artistid => $cur_row_data->[1] } ),
+
+        # prefetch data of cds (if available)
+        ( (! defined $cur_row_data->[3] ) ? $collapse_idx[3]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}}{cds} = [] : do {
+
+          (
+            (! $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{3}}{$cur_row_ids{4}}{$cur_row_ids{5}} )
+              and
+            push @{$collapse_idx[3]{$cur_row_ids{1}}{$cur_row_ids{4}}{$cur_row_ids{5}}{cds}}, (
+              $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{3}}{$cur_row_ids{4}}{$cur_row_ids{5}} = { cdid => $cur_row_data->[3] }
+            )
+          ),
+
+          # prefetch data of tracks (if available)
+          (( ! defined $cur_row_data->[0] ) ? $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{3}}{$cur_row_ids{4}}{$cur_row_ids{5}}{tracks} = [] : do {
+
+            (
+              (! $collapse_idx[5]{$cur_row_ids{0}}{$cur_row_ids{1}}{$cur_row_ids{3}}{$cur_row_ids{4}}{$cur_row_ids{5}} )
+                and
+              push @{$collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{3}}{$cur_row_ids{4}}{$cur_row_ids{5}}{tracks}}, (
+                $collapse_idx[5]{$cur_row_ids{0}}{$cur_row_ids{1}}{$cur_row_ids{3}}{$cur_row_ids{4}}{$cur_row_ids{5}} = { title => $cur_row_data->[0] }
+              )
+            ),
+          } ),
+        } ),
+      } ),
+    }
+    $#{$_[0]} = $result_pos - 1;
+  ',
+  'Same 1:1 descending terminating with chained 1:M:M but with collapse, HRI-direct',
+);
+
 $infmap = [qw/
-  tracks.lyrics.lyric_versions.text
+  tracks.lyrics.existing_lyric_versions.text
   existing_single_track.cd.artist.artistid
   existing_single_track.cd.artist.cds.year
   year
@@ -159,43 +460,32 @@ $infmap = [qw/
   latest_cd
   existing_single_track.cd.artist.cds.tracks.title
   existing_single_track.cd.artist.cds.genreid
+  tracks.lyrics.existing_lyric_versions.lyric_id
 /];
 
 is_deeply (
-  $schema->source('CD')->_resolve_collapse({map { $infmap->[$_] => $_ } 0 .. $#$infmap}),
+  $schema->source('CD')->_resolve_collapse({ as => {map { $infmap->[$_] => $_ } 0 .. $#$infmap} }),
   {
-    -node_index => 1,
-    -node_id => [ 1 ], # existing_single_track.cd.artist.artistid
-    -branch_id => [ 0, 1, 5, 6, 8 ],
+    -identifying_columns => [ 1 ], # existing_single_track.cd.artist.artistid
 
     existing_single_track => {
-      -node_index => 2,
-      -node_id => [ 1 ], # existing_single_track.cd.artist.artistid
-      -branch_id => [ 1, 6, 8 ],
+      -identifying_columns => [ 1 ], # existing_single_track.cd.artist.artistid
       -is_single => 1,
 
       cd => {
-        -node_index => 3,
-        -node_id => [ 1 ], # existing_single_track.cd.artist.artistid
-        -branch_id => [ 1, 6, 8 ],
+        -identifying_columns => [ 1 ], # existing_single_track.cd.artist.artistid
         -is_single => 1,
 
         artist => {
-          -node_index => 4,
-          -node_id => [ 1 ], # existing_single_track.cd.artist.artistid
-          -branch_id => [ 1, 6, 8 ],
+          -identifying_columns => [ 1 ], # existing_single_track.cd.artist.artistid
           -is_single => 1,
 
           cds => {
-            -node_index => 5,
-            -node_id => [ 6 ], # existing_single_track.cd.artist.cds.cdid
-            -branch_id => [ 6, 8 ],
+            -identifying_columns => [ 1, 6 ], # existing_single_track.cd.artist.cds.cdid
             -is_optional => 1,
 
             tracks => {
-              -node_index => 6,
-              -node_id => [ 6, 8 ], # existing_single_track.cd.artist.cds.cdid, existing_single_track.cd.artist.cds.tracks.title
-              -branch_id => [ 6, 8 ],
+              -identifying_columns => [ 1, 6, 8 ], # existing_single_track.cd.artist.cds.cdid, existing_single_track.cd.artist.cds.tracks.title
               -is_optional => 1,
             }
           }
@@ -203,23 +493,16 @@ is_deeply (
       }
     },
     tracks => {
-      -node_index => 7,
-      -node_id => [ 1, 5 ], # existing_single_track.cd.artist.artistid, tracks.title
-      -branch_id => [ 0, 1, 5 ],
+      -identifying_columns => [ 1, 5 ], # existing_single_track.cd.artist.artistid, tracks.title
       -is_optional => 1,
 
       lyrics => {
-        -node_index => 8,
-        -node_id => [ 1, 5 ], # existing_single_track.cd.artist.artistid, tracks.title
-        -branch_id => [ 0, 1, 5 ],
+        -identifying_columns => [ 1, 5, 10 ], # existing_single_track.cd.artist.artistid, tracks.title, tracks.lyrics.existing_lyric_versions.lyric_id
         -is_single => 1,
         -is_optional => 1,
 
-        lyric_versions => {
-          -node_index => 9,
-          -node_id => [ 0, 1, 5 ], # tracks.lyrics.lyric_versions.text, existing_single_track.cd.artist.artistid, tracks.title
-          -branch_id => [ 0, 1, 5 ],
-          -is_optional => 1,
+        existing_lyric_versions => {
+          -identifying_columns => [ 0, 1, 5, 10 ], # tracks.lyrics.existing_lyric_versions.text, existing_single_track.cd.artist.artistid, tracks.title, tracks.lyrics.existing_lyric_versions.lyric_id
         },
       },
     }
@@ -228,74 +511,967 @@ is_deeply (
 );
 
 is_same_src (
-  $schema->source ('CD')->_mk_row_parser({
+  ($schema->source ('CD')->_mk_row_parser({
     inflate_map => $infmap,
     collapse => 1,
-  }),
-  ' my ($rows_pos, $result_pos, $cur_row, @cur_row_ids, @collapse_idx, $is_new_res) = (0,0);
+  }))[0],
+  ' my $rows_pos = 0;
+    my ($result_pos, @collapse_idx, $cur_row_data, %cur_row_ids);
 
-    while ($cur_row = (
-      ( $rows_pos >= 0 and $_[0][$rows_pos++] ) or do { $rows_pos = -1; undef } )
-        ||
+    while ($cur_row_data = (
+      (
+        $rows_pos >= 0
+          and
+        (
+          $_[0][$rows_pos++]
+            or
+          ( ($rows_pos = -1), undef )
+        )
+      )
+        or
       ( $_[1] and $_[1]->() )
-    ) {
+    ) ) {
 
-      $cur_row_ids[$_] = defined $cur_row->[$_] ? $cur_row->[$_] : "\xFF\xFFN\xFFU\xFFL\xFFL\xFF\xFF"
-        for (0, 1, 5, 6, 8);
 
-      $is_new_res = ! $collapse_idx[1]{$cur_row_ids[1]} and (
-        $_[1] and $result_pos and (unshift @{$_[2]}, $cur_row) and last
-      );
+      # NULL checks
+      # mandatory => { 1 => 1 }
+      # from_first_encounter => [ [6, 8], [5, 10, 0] ],
+      #
+      ( defined( $cur_row_data->[1] ) or $_[3]->{1} = 1 ),
 
-      $collapse_idx[1]{$cur_row_ids[1]} ||= [{ latest_cd => $cur_row->[7], year => $cur_row->[3], genreid => $cur_row->[4] }];
+      (
+        ( not defined $cur_row_data->[6] )
+        ? (
+          ( not defined $cur_row_data->[8] )
+            or
+          ( $_[3]->{6} = 1 )
+        )
+      : ()
+      ),
 
-      $collapse_idx[1]{$cur_row_ids[1]}[1]{existing_single_track} ||= $collapse_idx[2]{$cur_row_ids[1]};
-      $collapse_idx[2]{$cur_row_ids[1]}[1]{cd} ||= $collapse_idx[3]{$cur_row_ids[1]};
-      $collapse_idx[3]{$cur_row_ids[1]}[1]{artist} ||= $collapse_idx[4]{$cur_row_ids[1]} ||= [{ artistid => $cur_row->[1] }];
+      (
+        ( not defined $cur_row_data->[5] )
+        ? (
+          ( not defined $cur_row_data->[10] )
+            and
+          ( not defined $cur_row_data->[0] )
+            or
+          ( $_[3]->{5} = 1 )
+          )
+      : ( not defined $cur_row_data->[10] )
+        ? (
+          ( not defined $cur_row_data->[0] )
+            or
+          ( $_[3]->{10} = 1 )
+        )
+      : ()
+      ),
 
-      $collapse_idx[4]{$cur_row_ids[1]}[1]{cds} ||= [];
-      push @{ $collapse_idx[4]{$cur_row_ids[1]}[1]{cds} }, $collapse_idx[5]{$cur_row_ids[6]} ||= [{ cdid => $cur_row->[6], genreid => $cur_row->[9], year => $cur_row->[2] }]
-        unless $collapse_idx[5]{$cur_row_ids[6]};
+      ( keys %{$_[3]} and (
+        ( @{$_[2]} = $cur_row_data ),
+        ( $result_pos = 0 ),
+        last
+      ) ),
 
-      $collapse_idx[5]{$cur_row_ids[6]}[1]{tracks} ||= [];
-      push @{ $collapse_idx[5]{$cur_row_ids[6]}[1]{tracks} }, $collapse_idx[6]{$cur_row_ids[6]}{$cur_row_ids[8]} ||= [{ title => $cur_row->[8] }]
-        unless $collapse_idx[6]{$cur_row_ids[6]}{$cur_row_ids[8]};
 
-      $collapse_idx[1]{$cur_row_ids[1]}[1]{tracks} ||= [];
-      push @{ $collapse_idx[1]{$cur_row_ids[1]}[1]{tracks} }, $collapse_idx[7]{$cur_row_ids[1]}{$cur_row_ids[5]} ||= [{ title => $cur_row->[5] }]
-        unless $collapse_idx[7]{$cur_row_ids[1]}{$cur_row_ids[5]};
+      ( @cur_row_ids{0, 1, 5, 6, 8, 10} = (
+        $cur_row_data->[0] // "\0NULL\xFF$rows_pos\xFF0\0",
+        $cur_row_data->[1],
+        $cur_row_data->[5] // "\0NULL\xFF$rows_pos\xFF5\0",
+        $cur_row_data->[6] // "\0NULL\xFF$rows_pos\xFF6\0",
+        $cur_row_data->[8] // "\0NULL\xFF$rows_pos\xFF8\0",
+        $cur_row_data->[10] // "\0NULL\xFF$rows_pos\xFF10\0",
+      ) ),
 
-      $collapse_idx[7]{$cur_row_ids[1]}{$cur_row_ids[5]}[1]{lyrics} ||= $collapse_idx[8]{$cur_row_ids[1]}{$cur_row_ids[5] };
+      # a present cref in $_[1] implies lazy prefetch, implies a supplied stash in $_[2]
+      ( $_[1] and $result_pos and ! $collapse_idx[0]{$cur_row_ids{1}} and (unshift @{$_[2]}, $cur_row_data) and last ),
 
-      $collapse_idx[8]{$cur_row_ids[1]}{$cur_row_ids[5]}[1]{lyric_versions} ||= [];
-      push @{ $collapse_idx[8]{$cur_row_ids[1]}{$cur_row_ids[5]}[1]{lyric_versions} }, $collapse_idx[9]{$cur_row_ids[0]}{$cur_row_ids[1]}{$cur_row_ids[5]} ||= [{ text => $cur_row->[0] }]
-        unless $collapse_idx[9]{$cur_row_ids[0]}{$cur_row_ids[1]}{$cur_row_ids[5]};
+      ( $collapse_idx[0]{$cur_row_ids{1}} //= $_[0][$result_pos++] = [{ genreid => $cur_row_data->[4], latest_cd => $cur_row_data->[7], year => $cur_row_data->[3] }] ),
 
-      $_[0][$result_pos++] = $collapse_idx[1]{$cur_row_ids[1]}
-        if $is_new_res;
+      ( $collapse_idx[0]{$cur_row_ids{1}}[1]{existing_single_track} //= $collapse_idx[1]{$cur_row_ids{1}} = [] ),
+      ( $collapse_idx[1]{$cur_row_ids{1}}[1]{cd} //= $collapse_idx[2]{$cur_row_ids{1}} = [] ),
+      ( $collapse_idx[2]{$cur_row_ids{1}}[1]{artist} //= $collapse_idx[3]{$cur_row_ids{1}} = [{ artistid => $cur_row_data->[1] }] ),
+
+      (
+        (! $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{6}} )
+          and
+        push @{ $collapse_idx[3]{$cur_row_ids{1}}[1]{cds} }, (
+          $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{6}} = [{ cdid => $cur_row_data->[6], genreid => $cur_row_data->[9], year => $cur_row_data->[2] }]
+        )
+      ),
+      ( defined($cur_row_data->[6]) or bless( $collapse_idx[3]{$cur_row_ids{1}}[1]{cds}, __NBC__ ) ),
+
+      (
+        (! $collapse_idx[5]{$cur_row_ids{1}}{$cur_row_ids{6}}{$cur_row_ids{8}} )
+          and
+        push @{ $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{6}}[1]{tracks} }, (
+          $collapse_idx[5]{$cur_row_ids{1}}{$cur_row_ids{6}}{$cur_row_ids{8}} = [{ title => $cur_row_data->[8] }]
+        )
+      ),
+      ( defined($cur_row_data->[8]) or bless( $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{6}}[1]{tracks}, __NBC__ ) ),
+
+      (
+        (! $collapse_idx[6]{$cur_row_ids{1}}{$cur_row_ids{5}} )
+          and
+        push @{ $collapse_idx[0]{$cur_row_ids{1}}[1]{tracks} }, (
+          $collapse_idx[6]{$cur_row_ids{1}}{$cur_row_ids{5}} = [{ title => $cur_row_data->[5] }]
+        )
+      ),
+      ( defined($cur_row_data->[5]) or bless( $collapse_idx[0]{$cur_row_ids{1}}[1]{tracks}, __NBC__ ) ),
+
+      ( $collapse_idx[6]{$cur_row_ids{1}}{$cur_row_ids{5}}[1]{lyrics} //= $collapse_idx[7]{$cur_row_ids{1}}{$cur_row_ids{5}}{$cur_row_ids{10}} = [] ),
+      ( defined($cur_row_data->[10]) or bless( $collapse_idx[6]{$cur_row_ids{1}}{$cur_row_ids{5}}[1]{lyrics}, __NBC__ ) ),
+
+      (
+        (! $collapse_idx[8]{$cur_row_ids{0}}{$cur_row_ids{1}}{$cur_row_ids{5}}{$cur_row_ids{10}} )
+          and
+        push @{ $collapse_idx[7]{$cur_row_ids{1}}{$cur_row_ids{5}}{$cur_row_ids{10}}[1]{existing_lyric_versions} }, (
+          $collapse_idx[8]{$cur_row_ids{0}}{$cur_row_ids{1}}{$cur_row_ids{5}}{$cur_row_ids{10}} = [{ lyric_id => $cur_row_data->[10], text => $cur_row_data->[0] }]
+        )
+      ),
     }
 
-    splice @{$_[0]}, $result_pos;
+    $#{$_[0]} = $result_pos - 1;
   ',
   'Multiple has_many on multiple branches torture test',
 );
 
+is_same_src (
+  ($schema->source ('CD')->_mk_row_parser({
+    inflate_map => $infmap,
+    collapse => 1,
+    prune_null_branches => 1,
+  }))[0],
+  ' my $rows_pos = 0;
+    my ($result_pos, @collapse_idx, $cur_row_data, %cur_row_ids);
+
+    while ($cur_row_data = (
+      (
+        $rows_pos >= 0
+          and
+        (
+          $_[0][$rows_pos++]
+            or
+          ( ($rows_pos = -1), undef )
+        )
+      )
+        or
+      ( $_[1] and $_[1]->() )
+    ) ) {
+
+
+      # NULL checks
+      # mandatory => { 1 => 1 }
+      # from_first_encounter => [ [6, 8], [5, 10, 0] ],
+      #
+      ( defined( $cur_row_data->[1] ) or $_[3]->{1} = 1 ),
+
+      (
+        ( not defined $cur_row_data->[6] )
+        ? (
+          ( not defined $cur_row_data->[8] )
+            or
+          ( $_[3]->{6} = 1 )
+        )
+      : ()
+      ),
+
+      (
+        ( not defined $cur_row_data->[5] )
+        ? (
+          ( not defined $cur_row_data->[10] )
+            and
+          ( not defined $cur_row_data->[0] )
+            or
+          ( $_[3]->{5} = 1 )
+          )
+      : ( not defined $cur_row_data->[10] )
+        ? (
+          ( not defined $cur_row_data->[0] )
+            or
+          ( $_[3]->{10} = 1 )
+        )
+      : ()
+      ),
+
+      ( keys %{$_[3]} and (
+        ( @{$_[2]} = $cur_row_data ),
+        ( $result_pos = 0 ),
+        last
+      ) ),
+
+
+      ( @cur_row_ids{( 0, 1, 5, 6, 8, 10 )} = @{$cur_row_data}[( 0, 1, 5, 6, 8, 10 )] ),
+
+      # a present cref in $_[1] implies lazy prefetch, implies a supplied stash in $_[2]
+      ( $_[1] and $result_pos and ! $collapse_idx[0]{$cur_row_ids{1}} and (unshift @{$_[2]}, $cur_row_data) and last ),
+
+      ( $collapse_idx[0]{$cur_row_ids{1}} //= $_[0][$result_pos++] = [{ genreid => $cur_row_data->[4], latest_cd => $cur_row_data->[7], year => $cur_row_data->[3] }] ),
+
+      ( $collapse_idx[0]{$cur_row_ids{1}}[1]{existing_single_track} //= $collapse_idx[1]{$cur_row_ids{1}} = [] ),
+      ( $collapse_idx[1]{$cur_row_ids{1}}[1]{cd} //= $collapse_idx[2]{$cur_row_ids{1}} = [] ),
+      ( $collapse_idx[2]{$cur_row_ids{1}}[1]{artist} //= $collapse_idx[3]{$cur_row_ids{1}} = [{ artistid => $cur_row_data->[1] }] ),
+
+      ( (! defined($cur_row_data->[6])) ? $collapse_idx[3]{$cur_row_ids{1}}[1]{cds} = [] : do {
+        (
+          (! $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{6}} )
+            and
+          push @{ $collapse_idx[3]{$cur_row_ids{1}}[1]{cds} }, (
+            $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{6}} = [{ cdid => $cur_row_data->[6], genreid => $cur_row_data->[9], year => $cur_row_data->[2] }]
+          )
+        ),
+
+        ( (! defined($cur_row_data->[8]) ) ? $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{6}}[1]{tracks} = [] : do {
+          (
+            (! $collapse_idx[5]{$cur_row_ids{1}}{$cur_row_ids{6}}{$cur_row_ids{8}} )
+              and
+            push @{ $collapse_idx[4]{$cur_row_ids{1}}{$cur_row_ids{6}}[1]{tracks} }, (
+              $collapse_idx[5]{$cur_row_ids{1}}{$cur_row_ids{6}}{$cur_row_ids{8}} = [{ title => $cur_row_data->[8] }]
+            )
+          ),
+        } ),
+      } ),
+
+      ( (! defined($cur_row_data->[5]) ) ? $collapse_idx[0]{$cur_row_ids{1}}[1]{tracks} = [] : do {
+
+        (
+          (! $collapse_idx[6]{$cur_row_ids{1}}{$cur_row_ids{5}} )
+            and
+          push @{ $collapse_idx[0]{$cur_row_ids{1}}[1]{tracks} }, (
+            $collapse_idx[6]{$cur_row_ids{1}}{$cur_row_ids{5}} = [{ title => $cur_row_data->[5] }]
+          )
+        ),
+
+        ( (! defined($cur_row_data->[10]) ) ? $collapse_idx[6]{$cur_row_ids{1}}{$cur_row_ids{5}}[1]{lyrics} = [] : do {
+
+          ( $collapse_idx[6]{$cur_row_ids{1}}{$cur_row_ids{5}}[1]{lyrics} //= $collapse_idx[7]{$cur_row_ids{1}}{$cur_row_ids{5}}{$cur_row_ids{10}} = [] ),
+
+          (
+            (! $collapse_idx[8]{$cur_row_ids{0}}{$cur_row_ids{1}}{$cur_row_ids{5}}{$cur_row_ids{10}} )
+              and
+            push @{ $collapse_idx[7]{$cur_row_ids{1}}{$cur_row_ids{5}}{$cur_row_ids{10}}[1]{existing_lyric_versions} }, (
+              $collapse_idx[8]{$cur_row_ids{0}}{$cur_row_ids{1}}{$cur_row_ids{5}}{$cur_row_ids{10}} = [{ lyric_id => $cur_row_data->[10], text => $cur_row_data->[0] }]
+            )
+          ),
+        } ),
+      } ),
+    }
+
+    $#{$_[0]} = $result_pos - 1;
+  ',
+  'Multiple has_many on multiple branches with branch pruning torture test',
+);
+
+$infmap = [
+  'single_track.trackid',                   # (0) definitive link to root from 1:1:1:1:M:M chain
+  'year',                                   # (1) non-unique
+  'tracks.cd',                              # (2) \ together both uniqueness for second multirel
+  'tracks.title',                           # (3) / and definitive link back to root
+  'single_track.cd.artist.cds.cdid',        # (4) to give uniquiness to ...tracks.title below
+  'single_track.cd.artist.cds.year',        # (5) non-unique
+  'single_track.cd.artist.artistid',        # (6) uniqufies entire parental chain
+  'single_track.cd.artist.cds.genreid',     # (7) nullable
+  'single_track.cd.artist.cds.tracks.title',# (8) unique when combined with ...cds.cdid above
+];
+
+is_deeply (
+  $schema->source('CD')->_resolve_collapse({ as => {map { $infmap->[$_] => $_ } 0 .. $#$infmap} }),
+  {
+    -identifying_columns => [],
+    -identifying_columns_variants => [
+      [ 0 ], [ 2 ],
+    ],
+    single_track => {
+      -identifying_columns => [ 0 ],
+      -is_optional => 1,
+      -is_single => 1,
+      cd => {
+        -identifying_columns => [ 0 ],
+        -is_single => 1,
+        artist => {
+          -identifying_columns => [ 0 ],
+          -is_single => 1,
+          cds => {
+            -identifying_columns => [ 0, 4 ],
+            -is_optional => 1,
+            tracks => {
+              -identifying_columns => [ 0, 4, 8 ],
+              -is_optional => 1,
+            }
+          }
+        }
+      }
+    },
+    tracks => {
+      -identifying_columns => [ 2, 3 ],
+      -is_optional => 1,
+    }
+  },
+  'Correct underdefined root collapse map constructed'
+);
+
+is_same_src (
+  ($schema->source ('CD')->_mk_row_parser({
+    inflate_map => $infmap,
+    collapse => 1,
+  }))[0],
+  ' my $rows_pos = 0;
+    my ($result_pos, @collapse_idx, $cur_row_data, %cur_row_ids);
+
+    while ($cur_row_data = (
+      (
+        $rows_pos >= 0
+          and
+        (
+          $_[0][$rows_pos++]
+            or
+          ( ($rows_pos = -1), undef )
+        )
+      )
+        or
+      ( $_[1] and $_[1]->() )
+    ) ) {
+
+
+      # NULL checks
+      #
+      # from_first_encounter => [ [0, 4, 8] ]
+      # all_or_nothing => [ { 2 => 1, 3 => 1 } ]
+      (
+        ( not defined $cur_row_data->[0] )
+        ? (
+          ( not defined $cur_row_data->[4] )
+            and
+          ( not defined $cur_row_data->[8] )
+            or
+          ( $_[3]->{0} = 1 )
+          )
+      : ( not defined $cur_row_data->[4] )
+        ? (
+          ( not defined $cur_row_data->[8] )
+            or
+          ( $_[3]->{4} = 1 )
+        )
+      : ()
+      ),
+
+      (
+        (
+          ( not defined $cur_row_data->[2] )
+            and
+          ( not defined $cur_row_data->[3] )
+        )
+          or
+        (
+          ( defined($cur_row_data->[2]) or $_[3]->{2} = 1 ),
+          ( defined($cur_row_data->[3]) or $_[3]->{3} = 1 ),
+        )
+      ),
+
+      ( keys %{$_[3]} and (
+        ( @{$_[2]} = $cur_row_data ),
+        ( $result_pos = 0 ),
+        last
+      ) ),
+
+
+      ( @cur_row_ids{( 0, 2, 3, 4, 8 )} = (
+        $cur_row_data->[0] // "\0NULL\xFF$rows_pos\xFF0\0",
+        $cur_row_data->[2] // "\0NULL\xFF$rows_pos\xFF2\0",
+        $cur_row_data->[3] // "\0NULL\xFF$rows_pos\xFF3\0",
+        $cur_row_data->[4] // "\0NULL\xFF$rows_pos\xFF4\0",
+        $cur_row_data->[8] // "\0NULL\xFF$rows_pos\xFF8\0",
+      )),
+
+      # cache expensive set of ops in a non-existent rowid slot
+      ( $cur_row_ids{10} = (
+        ( ( defined $cur_row_data->[0] ) && (join "\xFF", q{}, $cur_row_ids{0}, q{} ))
+          or
+        ( ( defined $cur_row_data->[2] ) && (join "\xFF", q{}, $cur_row_ids{2}, q{} ))
+          or
+        "\0$rows_pos\0"
+      )),
+
+      # a present cref in $_[1] implies lazy prefetch, implies a supplied stash in $_[2]
+      ( $_[1] and $result_pos and ! $collapse_idx[0]{$cur_row_ids{10}} and (unshift @{$_[2]}, $cur_row_data) and last ),
+
+      ( $collapse_idx[0]{$cur_row_ids{10}} //= $_[0][$result_pos++] = [{ year => $$cur_row_data[1] }] ),
+
+      ( $collapse_idx[0]{$cur_row_ids{10}}[1]{single_track} //= ($collapse_idx[1]{$cur_row_ids{0}} = [{ trackid => $cur_row_data->[0] }]) ),
+      ( defined($cur_row_data->[0]) or bless ( $collapse_idx[0]{$cur_row_ids{10}}[1]{single_track}, __NBC__ ) ),
+
+      ( $collapse_idx[1]{$cur_row_ids{0}}[1]{cd} //= $collapse_idx[2]{$cur_row_ids{0}} = [] ),
+
+      ( $collapse_idx[2]{$cur_row_ids{0}}[1]{artist} //= ($collapse_idx[3]{$cur_row_ids{0}} = [{ artistid => $cur_row_data->[6] }]) ),
+
+      (
+        (! $collapse_idx[4]{$cur_row_ids{0}}{$cur_row_ids{4}} )
+          and
+        push @{$collapse_idx[3]{$cur_row_ids{0}}[1]{cds}}, (
+          $collapse_idx[4]{$cur_row_ids{0}}{$cur_row_ids{4}} = [{ cdid => $cur_row_data->[4], genreid => $cur_row_data->[7], year => $cur_row_data->[5] }]
+        )
+      ),
+      ( defined($cur_row_data->[4]) or bless ( $collapse_idx[3]{$cur_row_ids{0}}[1]{cds}, __NBC__ ) ),
+
+      (
+        (! $collapse_idx[5]{$cur_row_ids{0}}{$cur_row_ids{4}}{$cur_row_ids{8}} )
+          and
+        push @{$collapse_idx[4]{$cur_row_ids{0}}{$cur_row_ids{4}}[1]{tracks}}, (
+            $collapse_idx[5]{$cur_row_ids{0}}{$cur_row_ids{4}}{$cur_row_ids{8}} = [{ title => $cur_row_data->[8] }]
+        )
+      ),
+      ( defined($cur_row_data->[8]) or bless ( $collapse_idx[4]{$cur_row_ids{0}}{$cur_row_ids{4}}[1]{tracks}, __NBC__ ) ),
+
+      (
+        (! $collapse_idx[6]{$cur_row_ids{2}}{$cur_row_ids{3}} )
+          and
+        push @{$collapse_idx[0]{$cur_row_ids{10}}[1]{tracks}}, (
+          $collapse_idx[6]{$cur_row_ids{2}}{$cur_row_ids{3}} = [{ cd => $$cur_row_data[2], title => $cur_row_data->[3] }]
+        )
+      ),
+      ( defined($cur_row_data->[2]) or bless ( $collapse_idx[0]{$cur_row_ids{10}}[1]{tracks}, __NBC__ ) ),
+    }
+
+    $#{$_[0]} = $result_pos - 1;
+  ',
+  'Multiple has_many on multiple branches with underdefined root torture test',
+);
+
+is_same_src (
+  ($schema->source ('CD')->_mk_row_parser({
+    inflate_map => $infmap,
+    collapse => 1,
+    hri_style => 1,
+    prune_null_branches => 1,
+  }))[0],
+  ' my $rows_pos = 0;
+    my ($result_pos, @collapse_idx, $cur_row_data, %cur_row_ids);
+
+    while ($cur_row_data = (
+      (
+        $rows_pos >= 0
+          and
+        (
+          $_[0][$rows_pos++]
+            or
+          ( ($rows_pos = -1), undef )
+        )
+      )
+        or
+      ( $_[1] and $_[1]->() )
+    ) ) {
+
+
+      # NULL checks
+      #
+      # from_first_encounter => [ [0, 4, 8] ]
+      # all_or_nothing => [ { 2 => 1, 3 => 1 } ]
+      (
+        ( not defined $cur_row_data->[0] )
+        ? (
+          ( not defined $cur_row_data->[4] )
+            and
+          ( not defined $cur_row_data->[8] )
+            or
+          ( $_[3]->{0} = 1 )
+          )
+      : ( not defined $cur_row_data->[4] )
+        ? (
+          ( not defined $cur_row_data->[8] )
+            or
+          ( $_[3]->{4} = 1 )
+        )
+      : ()
+      ),
+
+      (
+        (
+          ( not defined $cur_row_data->[2] )
+            and
+          ( not defined $cur_row_data->[3] )
+        )
+          or
+        (
+          ( defined($cur_row_data->[2]) or $_[3]->{2} = 1 ),
+          ( defined($cur_row_data->[3]) or $_[3]->{3} = 1 ),
+        )
+      ),
+
+      ( keys %{$_[3]} and (
+        ( @{$_[2]} = $cur_row_data ),
+        ( $result_pos = 0 ),
+        last
+      ) ),
+
+
+      # do not care about nullability here
+      ( @cur_row_ids{( 0, 2, 3, 4, 8 )} = @{$cur_row_data}[( 0, 2, 3, 4, 8 )] ),
+
+      # cache expensive set of ops in a non-existent rowid slot
+      ( $cur_row_ids{10} = (
+        ( ( defined $cur_row_data->[0] ) && (join "\xFF", q{}, $cur_row_ids{0}, q{} ))
+          or
+        ( ( defined $cur_row_data->[2] ) && (join "\xFF", q{}, $cur_row_ids{2}, q{} ))
+          or
+        "\0$rows_pos\0"
+      )),
+
+      # a present cref in $_[1] implies lazy prefetch, implies a supplied stash in $_[2]
+      ( $_[1] and $result_pos and ! $collapse_idx[0]{$cur_row_ids{10}} and (unshift @{$_[2]}, $cur_row_data) and last ),
+
+      ( $collapse_idx[0]{$cur_row_ids{10}} //= $_[0][$result_pos++] = { year => $$cur_row_data[1] } ),
+
+      ( (! defined $cur_row_data->[0] ) ? $collapse_idx[0]{$cur_row_ids{10}}{single_track} = undef : do {
+
+        ( $collapse_idx[0]{$cur_row_ids{10}}{single_track} //= ($collapse_idx[1]{$cur_row_ids{0}} = { trackid => $$cur_row_data[0] }) ),
+
+        ( $collapse_idx[1]{$cur_row_ids{0}}{cd} //= $collapse_idx[2]{$cur_row_ids{0}} = {} ),
+
+        ( $collapse_idx[2]{$cur_row_ids{0}}{artist} //= ($collapse_idx[3]{$cur_row_ids{0}} = { artistid => $$cur_row_data[6] }) ),
+
+        ( (! defined $cur_row_data->[4] ) ? $collapse_idx[3]{$cur_row_ids{0}}{cds} = [] : do {
+
+          (
+            (! $collapse_idx[4]{$cur_row_ids{0}}{$cur_row_ids{4}} )
+              and
+            push @{$collapse_idx[3]{$cur_row_ids{0}}{cds}}, (
+                $collapse_idx[4]{$cur_row_ids{0}}{$cur_row_ids{4}} = { cdid => $$cur_row_data[4], genreid => $$cur_row_data[7], year => $$cur_row_data[5] }
+            )
+          ),
+
+          ( (! defined $cur_row_data->[8] ) ? $collapse_idx[4]{$cur_row_ids{0}}{$cur_row_ids{4}}{tracks} = [] : do {
+
+            (! $collapse_idx[5]{$cur_row_ids{0}}{$cur_row_ids{4}}{$cur_row_ids{8}} )
+              and
+            push @{$collapse_idx[4]{$cur_row_ids{0}}{$cur_row_ids{4}}{tracks}}, (
+                $collapse_idx[5]{$cur_row_ids{0}}{$cur_row_ids{4}}{$cur_row_ids{8}} = { title => $$cur_row_data[8] }
+            ),
+          } ),
+        } ),
+      } ),
+
+      ( (! defined $cur_row_data->[2] ) ? $collapse_idx[0]{$cur_row_ids{10}}{tracks} = [] : do {
+        (
+          (! $collapse_idx[6]{$cur_row_ids{2}}{$cur_row_ids{3}} )
+            and
+          push @{$collapse_idx[0]{$cur_row_ids{10}}{tracks}}, (
+            $collapse_idx[6]{$cur_row_ids{2}}{$cur_row_ids{3}} = { cd => $$cur_row_data[2], title => $$cur_row_data[3] }
+          )
+        ),
+      } ),
+    }
+
+    $#{$_[0]} = $result_pos - 1;
+  ',
+  'Multiple has_many on multiple branches with underdefined root, HRI-direct torture test',
+);
+
+
+$infmap = [
+  'single_track.lyrics.track_id',             # (0) random optional 1:1:1 chain
+  'year',                                     # (1) non-unique
+  'tracks.cd',                                # (2) \ together both uniqueness for second multirel
+  'tracks.title',                             # (3) / and definitive link back to root
+  'single_track.cd.artist.cds.cdid',          # (4) to give uniquiness to ...tracks.title below
+  'single_track.cd.artist.cds.year',          # (5) non-unique
+  'single_track.cd.artist.artistid',          # (6) uniqufies entire parental chain
+  'single_track.cd.artist.cds.genreid',       # (7) nullable
+  'single_track.cd.artist.cds.tracks.title',  # (8) unique when combined with ...cds.cdid above
+  'single_track.lyrics.lyric_versions.text',  # (9) unique combined with the single_track.lyrics 1:1:1
+];
+
+is_deeply (
+  $schema->source('CD')->_resolve_collapse({ as => {map { $infmap->[$_] => $_ } 0 .. $#$infmap} }),
+  {
+    -identifying_columns => [],
+    -identifying_columns_variants => [
+      [ 2 ], [ 6 ],
+    ],
+    single_track => {
+      -identifying_columns => [ 6 ],
+      -is_optional => 1,
+      -is_single => 1,
+      cd => {
+        -identifying_columns => [ 6 ],
+        -is_single => 1,
+        artist => {
+          -identifying_columns => [ 6 ],
+          -is_single => 1,
+          cds => {
+            -identifying_columns => [ 4, 6 ],
+            -is_optional => 1,
+            tracks => {
+              -identifying_columns => [ 4, 6, 8 ],
+              -is_optional => 1,
+            }
+          }
+        }
+      },
+      lyrics => {
+        -identifying_columns => [ 0, 6 ],
+        -is_optional => 1,
+        -is_single => 1,
+        lyric_versions => {
+          -identifying_columns => [ 0, 6, 9 ],
+          -is_optional => 1,
+        },
+      },
+    },
+    tracks => {
+      -identifying_columns => [ 2, 3 ],
+      -is_optional => 1,
+    }
+  },
+  'Correct underdefined root tripple-has-many-torture collapse map constructed'
+);
+
+is_same_src (
+  ($schema->source ('CD')->_mk_row_parser({
+    inflate_map => $infmap,
+    collapse => 1,
+    hri_style => 1,
+    prune_null_branches => 1,
+  }))[0],
+  ' my $rows_pos = 0;
+    my ($result_pos, @collapse_idx, $cur_row_data, %cur_row_ids);
+
+    while ($cur_row_data = (
+      (
+        $rows_pos >= 0
+          and
+        (
+          $_[0][$rows_pos++]
+            or
+          ( ($rows_pos = -1), undef )
+        )
+      )
+        or
+      ( $_[1] and $_[1]->() )
+    ) ) {
+
+      # NULL checks
+      #
+      # from_first_encounter => [ [6, 4, 8], [6, 0, 9] ]
+      # all_or_nothing => [ { 2 => 1, 3 => 1 } ]
+      (
+        ( not defined $cur_row_data->[6] )
+        ? (
+          ( not defined $cur_row_data->[4] )
+            and
+          ( not defined $cur_row_data->[8] )
+            or
+          ( $_[3]->{6} = 1 )
+          )
+      : ( not defined $cur_row_data->[4] )
+        ? (
+          ( not defined $cur_row_data->[8] )
+            or
+          ( $_[3]->{4} = 1 )
+          )
+      : ()
+      ),
+
+      (
+        ( not defined $cur_row_data->[6] )
+        ? (
+          ( not defined $cur_row_data->[0] )
+            and
+          ( not defined $cur_row_data->[9] )
+            or
+          ( $_[3]->{6} = 1 )
+          )
+      : ( not defined $cur_row_data->[0] )
+        ? (
+          ( not defined $cur_row_data->[9] )
+            or
+          ( $_[3]->{0} = 1 )
+          )
+      : ()
+      ),
+
+      (
+        (
+          ( not defined $cur_row_data->[2] )
+            and
+          ( not defined $cur_row_data->[3] )
+        )
+          or
+        (
+          ( defined($cur_row_data->[2]) or $_[3]->{2} = 1 ),
+          ( defined($cur_row_data->[3]) or $_[3]->{3} = 1 ),
+        )
+      ),
+
+      ( keys %{$_[3]} and (
+        ( @{$_[2]} = $cur_row_data ),
+        ( $result_pos = 0 ),
+        last
+      ) ),
+
+
+      # do not care about nullability here
+      ( @cur_row_ids{( 0, 2, 3, 4, 6, 8, 9 )} = @{$cur_row_data}[( 0, 2, 3, 4, 6, 8, 9 )] ),
+
+      # cache expensive set of ops in a non-existent rowid slot
+      ( $cur_row_ids{11} = (
+        ( ( defined $cur_row_data->[2] ) && (join "\xFF", q{}, $cur_row_ids{2}, q{} ))
+          or
+        ( ( defined $cur_row_data->[6] ) && (join "\xFF", q{}, $cur_row_ids{6}, q{} ))
+          or
+        "\0$rows_pos\0"
+      )),
+
+      # a present cref in $_[1] implies lazy prefetch, implies a supplied stash in $_[2]
+      ( $_[1] and $result_pos and ! $collapse_idx[0]{$cur_row_ids{11}} and (unshift @{$_[2]}, $cur_row_data) and last ),
+
+      ( $collapse_idx[0]{$cur_row_ids{11}} //= $_[0][$result_pos++] = { year => $$cur_row_data[1] } ),
+
+      ( (! defined $cur_row_data->[6] ) ? $collapse_idx[0]{$cur_row_ids{11}}{single_track} = undef : do {
+
+        ( $collapse_idx[0]{$cur_row_ids{11}}{single_track} //= ( $collapse_idx[1]{$cur_row_ids{6}} = {} ) ),
+
+        ( $collapse_idx[1]{$cur_row_ids{6}}{cd} //= $collapse_idx[2]{$cur_row_ids{6}} = {} ),
+
+        ( $collapse_idx[2]{$cur_row_ids{6}}{artist} //= ($collapse_idx[3]{$cur_row_ids{6}} = { artistid => $$cur_row_data[6] }) ),
+
+        ( (! defined $cur_row_data->[4] ) ? $collapse_idx[3]{$cur_row_ids{6}}{cds} = [] : do {
+
+          (
+            (! $collapse_idx[4]{$cur_row_ids{4}}{$cur_row_ids{6}} )
+              and
+            push @{$collapse_idx[3]{$cur_row_ids{6}}{cds}}, (
+                $collapse_idx[4]{$cur_row_ids{4}}{$cur_row_ids{6}} = { cdid => $$cur_row_data[4], genreid => $$cur_row_data[7], year => $$cur_row_data[5] }
+            )
+          ),
+
+          ( (! defined $cur_row_data->[8] ) ? $collapse_idx[4]{$cur_row_ids{4}}{$cur_row_ids{6}}{tracks} = [] : do {
+
+            (! $collapse_idx[5]{$cur_row_ids{4}}{$cur_row_ids{6}}{$cur_row_ids{8}} )
+              and
+            push @{$collapse_idx[4]{$cur_row_ids{4}}{$cur_row_ids{6}}{tracks}}, (
+                $collapse_idx[5]{$cur_row_ids{4}}{$cur_row_ids{6}}{$cur_row_ids{8}} = { title => $$cur_row_data[8] }
+            ),
+          } ),
+        } ),
+
+        ( ( ! defined $cur_row_data->[0] ) ? $collapse_idx[1]{ $cur_row_ids{6} }{"lyrics"} = undef : do {
+
+          ( $collapse_idx[1]{ $cur_row_ids{6} }{"lyrics"} //= ( $collapse_idx[6]{ $cur_row_ids{0} }{ $cur_row_ids{6} } = { "track_id" => $cur_row_data->[0] } ) ),
+
+          ( ( ! defined $cur_row_data->[9] ) ? $collapse_idx[6]{ $cur_row_ids{0} }{ $cur_row_ids{6} }{"lyric_versions"} = [] : do {
+            (
+              (! $collapse_idx[7]{ $cur_row_ids{0} }{ $cur_row_ids{6} }{ $cur_row_ids{9} })
+                and
+              push @{$collapse_idx[6]{ $cur_row_ids{0} }{ $cur_row_ids{6} }{"lyric_versions"}}, (
+                $collapse_idx[7]{ $cur_row_ids{0} }{ $cur_row_ids{6} }{ $cur_row_ids{9} } = { "text" => $cur_row_data->[9] }
+              ),
+            ),
+          } ),
+        } ),
+      } ),
+
+      ( (! defined $cur_row_data->[2] ) ? $collapse_idx[0]{$cur_row_ids{11}}{tracks} = [] : do {
+        (
+          (! $collapse_idx[8]{$cur_row_ids{2}}{$cur_row_ids{3}} )
+            and
+          push @{$collapse_idx[0]{$cur_row_ids{11}}{tracks}}, (
+            $collapse_idx[8]{$cur_row_ids{2}}{$cur_row_ids{3}} = { cd => $$cur_row_data[2], title => $$cur_row_data[3] }
+          )
+        ),
+      } ),
+    }
+
+    $#{$_[0]} = $result_pos - 1;
+  ',
+  'Tripple multiple has_many on multiple branches with underdefined root, HRI-direct torture test',
+);
+
+is_same_src (
+  ($schema->source ('Owners')->_mk_row_parser({
+    inflate_map => [qw( books.title books.owner )],
+    collapse => 1,
+    prune_null_branches => 1,
+  }))[0],
+  ' my $rows_pos = 0;
+    my ($result_pos, @collapse_idx, $cur_row_data, %cur_row_ids );
+
+    while ($cur_row_data = (
+      (
+        $rows_pos >= 0
+          and
+        (
+          $_[0][$rows_pos++]
+            or
+          ( ($rows_pos = -1), undef )
+        )
+      )
+        or
+      ( $_[1] and $_[1]->() )
+    ) ) {
+
+      ( @cur_row_ids{0,1} = @{$cur_row_data}[0,1] ),
+
+      ( $cur_row_ids{3} = (
+        ( ( defined $cur_row_data->[1] ) && (join "\xFF", q{}, $cur_row_ids{1}, q{} ))
+          or
+        "\0${rows_pos}\0"
+      )),
+
+      ( $_[1] and $result_pos and ! $collapse_idx[0]{$cur_row_ids{3}} and (unshift @{$_[2]}, $cur_row_data) and last ),
+
+      # empty data for the root node
+      ( $collapse_idx[0]{$cur_row_ids{3}} //= $_[0][$result_pos++] = [] ),
+
+      ( ( ! defined $cur_row_data->[0] ) ? $collapse_idx[0]{$cur_row_ids{3}}[1]{"books"} = [] : do {
+        ( ! $collapse_idx[1]{$cur_row_ids{0}} )
+          and
+        push @{$collapse_idx[0]{$cur_row_ids{3}}[1]{books}},
+          $collapse_idx[1]{$cur_row_ids{0}} = [ { owner => $cur_row_data->[1], title => $cur_row_data->[0] } ]
+      } ),
+    }
+
+    $#{$_[0]} = $result_pos - 1; # truncate the passed in array to where we filled it with results
+  ',
+  'Non-premultiplied implicit collapse with missing join columns',
+);
+
+is_same_src (
+  ($schema->source('Artist')->_mk_row_parser({
+    inflate_map => [qw( artistid cds.artist cds.title cds.tracks.title )],
+    collapse => 1,
+    prune_null_branches => 1,
+  }))[0],
+  ' my $rows_pos = 0;
+    my ($result_pos, @collapse_idx, $cur_row_data, %cur_row_ids );
+
+    while ($cur_row_data = (
+      (
+        $rows_pos >= 0
+          and
+        (
+          $_[0][$rows_pos++]
+            or
+          ( ($rows_pos = -1), undef )
+        )
+      )
+        or
+      ( $_[1] and $_[1]->() )
+    ) ) {
+
+      # NULL checks
+      #
+      # mandatory => { 0 => 1 }
+      # from_first_encounter => [ [1, 2, 3] ]
+      # all_or_nothing => [ { 1 => 1, 2 => 1 } ]
+
+      ( defined( $cur_row_data->[0] ) or $_[3]->{0} = 1 ),
+
+      (
+        ( not defined $cur_row_data->[1] )
+        ? (
+          ( not defined $cur_row_data->[2] )
+            and
+          ( not defined $cur_row_data->[3] )
+            or
+          $_[3]->{1} = 1
+          )
+      : ( not defined $cur_row_data->[2] )
+        ? (
+          ( not defined $cur_row_data->[3] )
+            or
+          $_[3]->{2} = 1
+          )
+      : ()
+      ),
+
+      (
+        (
+          ( not defined $cur_row_data->[1] )
+            and
+          ( not defined $cur_row_data->[2] )
+        )
+          or
+        (
+          ( defined($cur_row_data->[1]) or $_[3]->{1} = 1 ),
+          ( defined($cur_row_data->[2]) or $_[3]->{2} = 1 ),
+        )
+      ),
+
+      ( keys %{$_[3]} and (
+        ( @{$_[2]} = $cur_row_data ),
+        ( $result_pos = 0 ),
+        last
+      ) ),
+
+
+      ( @cur_row_ids{( 0, 1, 2, 3 )} = @{$cur_row_data}[ 0, 1, 2, 3 ] ),
+
+      ( $_[1] and $result_pos and ! $collapse_idx[0]{$cur_row_ids{0}} and (unshift @{$_[2]}, $cur_row_data) and last ),
+
+      ( $collapse_idx[0]{ $cur_row_ids{0} }
+          //= $_[0][$result_pos++] = [ { "artistid" => $cur_row_data->[0] } ]
+      ),
+
+      ( ( ! defined $cur_row_data->[1] ) ? $collapse_idx[0]{ $cur_row_ids{0} }[1]{"cds"} = [] : do {
+
+        (
+          ! $collapse_idx[1]{ $cur_row_ids{0} }{ $cur_row_ids{1} }{ $cur_row_ids{2} }
+            and
+          push @{$collapse_idx[0]{ $cur_row_ids{0} }[1]{"cds"}},
+            $collapse_idx[1]{ $cur_row_ids{0} }{ $cur_row_ids{1} }{ $cur_row_ids{2} }
+              = [ { "artist" => $cur_row_data->[1], "title" => $cur_row_data->[2] } ]
+        ),
+
+        ( ( ! defined $cur_row_data->[3] ) ? $collapse_idx[1]{ $cur_row_ids{0} }{ $cur_row_ids{1} }{ $cur_row_ids{2} }[1]{"tracks"} = [] : do {
+          (
+            ! $collapse_idx[2]{ $cur_row_ids{0} }{ $cur_row_ids{1} }{ $cur_row_ids{2} }{ $cur_row_ids{3} }
+              and
+            push @{$collapse_idx[1]{ $cur_row_ids{0} }{ $cur_row_ids{1} }{ $cur_row_ids{2} }[1]{"tracks"}},
+              $collapse_idx[2]{ $cur_row_ids{0} }{ $cur_row_ids{1} }{ $cur_row_ids{2} }{ $cur_row_ids{3} }
+                = [ { "title" => $cur_row_data->[3] } ]
+          ),
+        } ),
+      } ),
+    }
+
+    $#{$_[0]} = $result_pos - 1
+  ',
+  'A rolled out version of inflate map of misled_rowparser.t'
+);
+
 done_testing;
 
 my $deparser;
-sub is_same_src {
+sub is_same_src { SKIP: {
+
+  skip "Skipping comparison of unicode-poisoned source", 1
+    if DBIx::Class::_ENV_::STRESSTEST_UTF8_UPGRADE_GENERATED_COLLAPSER_SOURCE;
+
   $deparser ||= B::Deparse->new;
   local $Test::Builder::Level = $Test::Builder::Level + 1;
 
-  my ($got, $expect) = map {
+  my ($got, $expect) = @_;
+
+  skip "Not testing equality of source containing defined-or operator on this perl $]", 1
+    if ( "$]" < 5.010 and $expect =~ m!\Q//=! );
+
+  $expect =~ s/__NBC__/perlstring($DBIx::Class::ResultSource::RowParser::Util::null_branch_class)/ge;
+
+  $expect = "sub { use strict; use warnings FATAL => 'uninitialized';\n$expect\n  }";
+
+  my @normalized = map {
     my $cref = eval "sub { $_ }" or do {
       fail "Coderef does not compile!\n\n$@\n\n$_";
       return undef;
     };
     $deparser->coderef2text($cref);
-  } @_[0,1];
-
-  is ($got, $expect, $_[2]||() )
-    or note ("Originals source:\n\n$_[0]\n\n$_[1]\n");
-}
+  } ($got, $expect);
 
+  &is (@normalized, $_[2]||() ) or do {
+    eval { require Test::Differences }
+      ? &Test::Differences::eq_or_diff( @normalized, $_[2]||() )
+      : note ("Original sources:\n\n$got\n\n$expect\n")
+    ;
+    exit 1;
+  };
+} }