Fix issue where mixed readonly/read-write dirs didn't hard link

CHANGELOG.md

@@ -14,6 +14,11 @@ All notable changes to this project will be documented in this file.
 - Omit output of progress bar unless -v flag is present
 - Add thousands separator commas to output
 
+### Fixed
+
+- Fixed issue where removable files wouldn't be linked with non-removable
+  files.
+
 ## [3.0.0]
 
 ### Changed

lib/Directory/Simplify/Instruction/Generator.pm

@@ -145,17 +145,23 @@ sub instructions {
         my ($oldest_entry) = _oldest_mtime(@{$bucket});
 
         # Limit link/unlink operations to files in non-readonly directories
-        my @non_readonly;
+        my (@non_readonly, @readonly);
         foreach my $entry (@{$bucket}) {
             unless (-w $entry->{dirname}) {
                 carp "Warning: $entry->{name} not able to be unlinked!";
+                push @readonly, $entry;
+            } else {
+                push @non_readonly, $entry;
             }
-            push @non_readonly, $entry;
         }
 
         # Of the linkable files, find the file most embedded in the file system
         my @to_link = _more_linked(@non_readonly);
-        my $most_linked_entry = shift @to_link;
+        @readonly = _more_linked(@readonly);
+
+        # Select a basis for linkage, either the most-linked readonly entry (if
+        # any) or the most linked of the read-write entries.
+        my $most_linked_entry = shift @readonly // shift @to_link;
         foreach my $entry (@to_link) {
             # XXX there shouldn't be a need to update entries' link counts,
             # since this generates all the instructions at once