Fix `dir_config` cache for -include and -lib options

Set to "--with-" options, not "--without-" keys.

1 files changed, 6 insertions, 2 deletions

diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index ec869c812a..6da7dde5f1 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -1803,9 +1803,13 @@ SRC
     end
 
     idir = with_config(target + "-include", idefault)
-    $arg_config.last[1] ||= "${#{target}-dir}/include"
+    if conf = $arg_config.assoc("--with-#{target}-include")
+      conf[1] ||= "${#{target}-dir}/include"
+    end
     ldir = with_config(target + "-lib", ldefault)
-    $arg_config.last[1] ||= "${#{target}-dir}/#{_libdir_basename}"
+    if conf = $arg_config.assoc("--with-#{target}-lib")
+      conf[1] ||= "${#{target}-dir}/#{_libdir_basename}"
+    end
 
     idirs = idir ? Array === idir ? idir.dup : idir.split(File::PATH_SEPARATOR) : []
     if defaults