Ensure that Gem::Specification#git_version can be called safely in a repo with no commits.

2 files changed, 10 insertions, 6 deletions

diff --git a/lib/bundler/rubygems_ext.rb b/lib/bundler/rubygems_ext.rb
index 9f50d9621b..6661d2039c 100644
--- a/lib/bundler/rubygems_ext.rb
+++ b/lib/bundler/rubygems_ext.rb
@@ -57,7 +57,9 @@ module Gem
 
     def git_version
       if @loaded_from && File.exist?(File.join(full_gem_path, ".git"))
-        sha = Bundler::SharedHelpers.chdir(full_gem_path){ `git rev-parse HEAD`.strip }
+        sha = Bundler::SharedHelpers.chdir(full_gem_path) do
+          null_command("git rev-parse HEAD").strip
+        end
         " #{sha[0..6]}"
       end
     end
@@ -94,6 +96,12 @@ module Gem
       gemfile
     end
 
+    # TODO: Do not rely on /dev/null.
+    # see https://github.com/bundler/bundler/blob/98f79a1d/lib/bundler/source/git/git_proxy.rb#L97-101
+    def null_command(command)
+      `#{command} 2>#{Bundler::NULL}`.tap {|out| return `#{command}` if out.empty? }
+    end
+
   end
 
   class Dependency
diff --git a/lib/bundler/source/git/git_proxy.rb b/lib/bundler/source/git/git_proxy.rb
index 7d8b5d404b..a059a7cf89 100644
--- a/lib/bundler/source/git/git_proxy.rb
+++ b/lib/bundler/source/git/git_proxy.rb
@@ -101,11 +101,7 @@ module Bundler
         # If it doesn't, everything will work fine, but the user
         # will get the $stderr messages as well.
         def git_null(command)
-          if !Bundler::WINDOWS && File.exist?("/dev/null")
-            git("#{command} 2>/dev/null", false)
-          else
-            git(command, false)
-          end
+          git("#{command} 2>#{Bundler::NULL}", false)
         end
 
         def git(command, check_errors=true)