extmk.rb: fix with-ext condition

* ext/extmk.rb: configure intersection of with-ext and not
  without-ext, as withouts is no longer true by default if
  with-ext option is given.  [ruby-dev:49108] [Bug #11280]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50959 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Thu Jun 18 23:25:51 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/extmk.rb: configure intersection of with-ext and not
+	  without-ext, as withouts is no longer true by default if
+	  with-ext option is given.  [ruby-dev:49108] [Bug #11280]
+
 Thu Jun 18 23:20:46 2015  SHIBATA Hiroshi  <hsbt@ruby-lang.org>
 
 	* include/ruby/ruby.h: $SAFE=2 is now obsolete.

ext/extmk.rb

@@ -514,7 +514,7 @@ withes, withouts = [["--with", nil], ["--without", default_exclude_exts]].collec
 }
 cond = proc {|ext, *|
   cond1 = proc {|n| File.fnmatch(n, ext)}
-  withes.call(cond1) or !withouts.call(cond1)
+  withes.call(cond1) and !withouts.call(cond1)
 }
 ($extension || %w[*]).each do |e|
   e = e.sub(/\A(?:\.\/)+/, '')