add support for copying lists in head3 sections

Author: book

Porting/merge-deltas.pl

@@ -125,6 +125,41 @@ ( $tree, $directive, $pos = 0 )
           ->@[ 2 .. $delta->[$delta_list_pos]->$#* ];
     },
 
+    # =item entries inside a =head3
+    item_head3 =>  sub ( $master, $title, $delta ) {
+
+        # find the section in the delta and master
+        my ( $master_pos, $delta_pos ) =
+          map header_pos( $_, 1, $title ),
+          $master, $delta;
+
+        # loop over the =head2 in the section
+        while ( $delta_pos = next_header_pos( $delta, 2, $delta_pos ) ) {
+
+            my $section_title = $delta->[$delta_pos][2];
+            $master_pos =    # find the same =head2 in the master
+              header_pos( $master, 2, $section_title, $master_pos );
+
+            # loop over the =head3 in the section
+            while ( $delta_pos = next_header_pos( $delta, 3, $delta_pos ) ) {
+                $section_title = $delta->[$delta_pos][2];
+                $master_pos =    # find the same =head2 in the master
+                  header_pos( $master, 3, $section_title, $master_pos );
+
+                # find the =over in both
+                my ( $master_list_pos, $delta_list_pos ) = (
+                    next_directive_pos( $master, 'over-bullet', $master_pos ),
+                    next_directive_pos( $delta,  'over-bullet', $delta_pos )
+                );
+
+                # inject the list from delta into the master
+                push $master->[$master_list_pos]->@*,
+                  $delta->[$delta_list_pos]
+                  ->@[ 2 .. $delta->[$delta_list_pos]->$#* ];
+            }
+        }
+    },
+
     # copy the whole section content
     copy => sub ( $master, $title, $delta ) {
 
@@ -193,7 +228,7 @@ ( $tree, $directive, $pos = 0 )
     'Performance Enhancements'      => 'item',
     'Modules and Pragmata'          => 'skip',
     'Documentation'                 => 'head3',
-    'Diagnostics'                   => 'skip',
+    'Diagnostics'                   => 'item_head3',
     'Utility Changes'               => 'head2',
     'Configuration and Compilation' => 'item',
     'Testing'                       => 'item',