fake.rb: fix builddir

* tool/fake.rb (prehook): consider the case building under the
  source directory.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52439 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 1 deletions

diff --git a/tool/fake.rb b/tool/fake.rb
index b2bdd086c4..9fe95a5bd6 100644
--- a/tool/fake.rb
+++ b/tool/fake.rb
@@ -41,7 +41,7 @@ prehook = proc do |extmk|
       dir.shift
       pwd.shift
     end
-    builddir = File.join([".."]*pwd.size + dir)
+    builddir = File.join((pwd.empty? ? ["."] : [".."]*pwd.size) + dir)
     builddir = "." if builddir.empty?
   end
   join = proc {|*args| File.join(*args).sub!(/\A(?:\.\/)*/, '')}