diff --git a/Library/Homebrew/test/unpack_strategy/directory_spec.rb b/Library/Homebrew/test/unpack_strategy/directory_spec.rb index d1320f808cf0c..232a8d4b31353 100644 --- a/Library/Homebrew/test/unpack_strategy/directory_spec.rb +++ b/Library/Homebrew/test/unpack_strategy/directory_spec.rb @@ -9,6 +9,7 @@ mktmpdir.tap do |path| FileUtils.touch path/"file" FileUtils.ln_s "file", path/"symlink" + FileUtils.ln path/"file", path/"hardlink" FileUtils.mkdir path/"folder" FileUtils.ln_s "folder", path/"folderSymlink" end @@ -26,6 +27,11 @@ expect(unpack_dir/"folderSymlink").to be_a_symlink end + it "preserves hardlinks" do + strategy.extract(to: unpack_dir) + expect((unpack_dir/"file").stat.ino).to eq (unpack_dir/"hardlink").stat.ino + end + it "preserves permissions of contained files" do FileUtils.chmod 0644, path/"file" diff --git a/Library/Homebrew/unpack_strategy/directory.rb b/Library/Homebrew/unpack_strategy/directory.rb index 62c76284bd014..8db0bc9fde4db 100644 --- a/Library/Homebrew/unpack_strategy/directory.rb +++ b/Library/Homebrew/unpack_strategy/directory.rb @@ -20,11 +20,29 @@ def self.can_extract?(path) sig { override.params(unpack_dir: Pathname, basename: Pathname, verbose: T::Boolean).void } def extract_to_dir(unpack_dir, basename:, verbose:) - path.children.each do |child| - system_command! "cp", - args: ["-pR", (child.directory? && !child.symlink?) ? "#{child}/." : child, - unpack_dir/child.basename], - verbose: + path_children = path.children + return if path_children.empty? + + existing = unpack_dir.children + + # We run a few cp attempts in the following order: + # + # 1. Start with `-al` to create hardlinks rather than copying files if the source and + # target are on the same filesystem. On macOS, this is the only cp option that can + # preserve hardlinks but it is only available since macOS 12.3 (file_cmds-353.100.22). + # 2. Try `-a` as GNU `cp -a` preserves hardlinks. macOS `cp -a` is identical to `cp -pR`. + # 3. Fall back on `-pR` to handle the case where GNU `cp -a` failed. This may happen if + # installing into a filesystem that doesn't support hardlinks like an exFAT USB drive. + cp_arg_attempts = ["-a", "-pR"] + cp_arg_attempts.unshift("-al") if path.stat.dev == unpack_dir.stat.dev + + cp_arg_attempts.each do |arg| + args = [arg, *path_children, unpack_dir] + must_succeed = print_stderr = (arg == cp_arg_attempts.last) + result = system_command("cp", args:, verbose:, must_succeed:, print_stderr:) + break if result.success? + + FileUtils.rm_r(unpack_dir.children - existing) end end end