[GR-18163] Update patch feature finding to prefer the longest matching load path

PullRequest: truffleruby/3204

Author: bjfish

CHANGELOG.md

@@ -14,6 +14,7 @@ Bug fixes:
 * Fix `Integer#{<<,>>}` with RHS bignum and long (@eregon).
 * Fix a resource leak from allocators defined in C extensions (@aardvark179).
 * `SIGINT`/`Interrupt`/`Ctrl+C` now shows the backtrace and exits as signaled, like CRuby (@eregon).
+* Update patch feature finding to prefer the longest matching load path (#2605, @bjfish).
 
 Compatibility:
 

src/main/ruby/truffleruby/core/truffle/feature_loader.rb

@@ -219,10 +219,11 @@ def self.provide_feature(feature)
     end
 
     def self.relative_feature(expanded_path)
-      load_path_entry = get_expanded_load_path.find do |load_dir|
+      load_path_entries = get_expanded_load_path.select do |load_dir|
         expanded_path.start_with?(load_dir) and expanded_path[load_dir.size] == '/'
       end
-      if load_path_entry
+      if !load_path_entries.empty?
+        load_path_entry = load_path_entries.max_by(&:length)
         before_dot_rb = expanded_path.end_with?('.rb') ? -4 : -1
         expanded_path[load_path_entry.size+1..before_dot_rb]
       else