extmk.rb: fix with-ext condition

* ext/extmk.rb: if no with-ext option is given, dafault to
  enable everything.  [ruby-dev:49108] [Bug #11280]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50966 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Fri Jun 19 07:58:11 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/extmk.rb: if no with-ext option is given, dafault to
+	  enable everything.  [ruby-dev:49108] [Bug #11280]
+
 Fri Jun 19 06:30:07 2015  Koichi Sasada  <ko1@atdot.net>
 
 	* bootstraptest/test_method.rb: remove a test because $SAFE=2 was

ext/extmk.rb

@@ -503,7 +503,7 @@ default_exclude_exts =
   end
 withes, withouts = [["--with", nil], ["--without", default_exclude_exts]].collect {|w, d|
   if !(w = %w[-extensions -ext].collect {|o|arg_config(w+o)}).any?
-    d ? proc {|c1| d.any?(&c1)} : proc {false}
+    d ? proc {|c1| d.any?(&c1)} : proc {true}
   elsif (w = w.grep(String)).empty?
     proc {true}
   else