*: Ruby 2.0 compatibility branch

This branch is a special compatibility branch for
Ruby 2.0, 2.1, and 2.2.

It represents the last version of ruby-macho to support
these older Rubies.

Author: woodruffw

.travis.yml

@@ -1,5 +1,8 @@
 language: ruby
 rvm:
+    - 2.0
+    - 2.1
+    - 2.2
     - 2.3
     - 2.4
     - 2.5
@@ -8,5 +11,4 @@ sudo: false
 before_install:
   - gem update --system # https://github.com/travis-ci/travis-ci/issues/8978
 script:
-  - bundle exec rake
-  - bundle exec rubocop -D lib/
+  - ./run-tests

Gemfile

@@ -5,5 +5,6 @@ group :test do
   gem "codecov", require: false, group: :test
   gem "minitest"
   gem "rake"
-  gem "rubocop"
+
+  gem "rubocop" if RUBY_VERSION >= "2.2"
 end

Gemfile.lock

@@ -12,7 +12,7 @@
 # The primary namespace for ruby-macho.
 module MachO
   # release version
-  VERSION = "2.1.0".freeze
+  VERSION = "1.3.0".freeze
 
   # Opens the given filename as a MachOFile or FatFile, depending on its magic.
   # @param filename [String] the file being opened

lib/macho.rb

@@ -39,7 +39,11 @@ def self.new_from_machos(*machos, fat64: false)
       # put the smaller alignments further forwards in fat macho, so that we do less padding
       machos = machos.sort_by(&:segment_alignment)
 
-      bin = +""
+      bin = if String.instance_methods.include? :+@
+        +""
+      else
+        ""
+      end
 
       bin << Headers::FatHeader.new(magic, machos.size).serialize
       offset = Headers::FatHeader.bytesize + (machos.size * fa_klass.bytesize)

lib/macho/fat_file.rb

@@ -27,7 +27,7 @@ def self.padding_for(size, alignment)
     # @return [String] the null string (or empty string, for `size = 0`)
     # @raise [ArgumentError] if a non-positive nullpad is requested
     def self.nullpad(size)
-      raise ArgumentError, "size < 0: #{size}" if size.negative?
+      raise ArgumentError, "size < 0: #{size}" if size < 0
 
       "\x00" * size
     end

lib/macho/utils.rb

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 
 die() {
   echo "Error: $*" >&2
@@ -24,11 +24,17 @@ if ! bundle check ; then
 fi
 echo
 
-# Run rubocop.
-echo ">> Running style enforcement."
-bundle exec rubocop -DES
-result="$?"
-echo
+read -r major minor < <(ruby -e 'puts RUBY_VERSION' | awk -F. '{ print $1, $2 }')
+
+if [[ "${major}" -eq 2 && "${minor}" -ge 2 ]]; then
+    # Run rubocop.
+    echo ">> Running style enforcement."
+    bundle exec rubocop -DES lib/
+    result="$?"
+    echo ">> Done: ${result}."
+else
+    echo ">> Older ruby, skipping style enforcement."
+fi
 
 echo ">> Done: ${result}."