Implement :checksum_hash mrbgem option.

This allows to use a mgem with a specific checksum hash.
The following modification were necessary to implement this
function:
  - add run_checkout build command to use 'git checkout'
  - skip shallow copy in case checksum_hash is used
  - make 'master' the default branch if branch isn't defined

1 files changed, 11 insertions, 2 deletions

diff --git a/tasks/mruby_build_commands.rake b/tasks/mruby_build_commands.rake
index d64b20ff3..4beb7e743 100644
--- a/tasks/mruby_build_commands.rake
+++ b/tasks/mruby_build_commands.rake
@@ -228,14 +228,15 @@ module MRuby
 
   class Command::Git < Command
     attr_accessor :flags
-    attr_accessor :clone_options, :pull_options
+    attr_accessor :clone_options, :pull_options, :checkout_options
 
     def initialize(build)
       super
       @command = 'git'
-      @flags = %w[--depth 1]
+      @flags = %w[]
       @clone_options = "clone %{flags} %{url} %{dir}"
       @pull_options = "pull"
+      @checkout_options = "checkout %{checksum_hash}"
     end
 
     def run_clone(dir, url, _flags = [])
@@ -250,6 +251,14 @@ module MRuby
       _run pull_options
       Dir.chdir root
     end
+
+    def run_checkout(dir, checksum_hash)
+      root = Dir.pwd
+      Dir.chdir dir
+      _pp "GIT CHECKOUT", checksum_hash
+      _run checkout_options, { :checksum_hash => checksum_hash }
+      Dir.chdir root
+    end
   end
 
   class Command::Mrbc < Command