[ruby-dev:35685] encoding of Dir#path

以下のように、Dir#path で返ってくるもののエンコーディングが、
Dir.open に渡したものと異なるのは変ではないでしょうか。

% ./ruby -Ku -ve '
dirname = "/tmp/\x91\x92\x93"
Dir.mkdir(dirname)
p [dirname, dirname.encoding]
d = Dir.open(dirname)
dirname2 = d.path
p [dirname2, dirname2.encoding]
'
ruby 1.9.0 (2008-07-29 revision 18257) [i686-linux]
["/tmp/\x91\x92\x93", #<Encoding:UTF-8>]
["/tmp/\x91\x92\x93", #<Encoding:EUC-JP>]

というわけで以下のようにするのはどうでしょう。

Index: dir.c
===================================================================
--- dir.c	(revision 18254)
+++ dir.c	(working copy)
@@ -290,16 +290,21 @@ VALUE rb_cDir;
 
 struct dir_data {
     DIR *dir;
-    char *path;
+    VALUE path;
     rb_encoding *extenc;
 };
 
 static void
+mark_dir(struct dir_data *dir)
+{
+    rb_gc_mark(dir->path);
+}
+
+static void
 free_dir(struct dir_data *dir)
 {
     if (dir) {
 	if (dir->dir) closedir(dir->dir);
-	if (dir->path) xfree(dir->path);
     }
     xfree(dir);
 }
@@ -310,10 +315,10 @@ static VALUE
 dir_s_alloc(VALUE klass)
 {
     struct dir_data *dirp;
-    VALUE obj = Data_Make_Struct(klass, struct dir_data, 0, free_dir, dirp);
+    VALUE obj = Data_Make_Struct(klass, struct dir_data, mark_dir, free_dir, dirp);
 
     dirp->dir = NULL;
-    dirp->path = NULL;
+    dirp->path = Qnil;
     dirp->extenc = NULL;
 
     return obj;
@@ -358,9 +363,8 @@ dir_initialize(int argc, VALUE *argv, VA
 
     Data_Get_Struct(dir, struct dir_data, dp);
     if (dp->dir) closedir(dp->dir);
-    if (dp->path) xfree(dp->path);
     dp->dir = NULL;
-    dp->path = NULL;
+    dp->path = Qnil;
     dp->extenc = extencoding;
     dp->dir = opendir(RSTRING_PTR(dirname));
     if (dp->dir == NULL) {
@@ -372,7 +376,7 @@ dir_initialize(int argc, VALUE *argv, VA
 	    rb_sys_fail(RSTRING_PTR(dirname));
 	}
     }
-    dp->path = strdup(RSTRING_PTR(dirname));
+    dp->path = rb_str_dup_frozen(dirname);
 
     return dir;
 }
@@ -392,7 +396,7 @@ static VALUE
 dir_s_open(int argc, VALUE *argv, VALUE klass)
 {
     struct dir_data *dp;
-    VALUE dir = Data_Make_Struct(klass, struct dir_data, 0, free_dir, dp);
+    VALUE dir = Data_Make_Struct(klass, struct dir_data, mark_dir, free_dir, dp);
 
     dir_initialize(argc, argv, dir);
     if (rb_block_given_p()) {
@@ -441,9 +445,9 @@ dir_inspect(VALUE dir)
     struct dir_data *dirp;
 
     Data_Get_Struct(dir, struct dir_data, dirp);
-    if (dirp->path) {
+    if (!NIL_P(dirp->path)) {
 	const char *c = rb_obj_classname(dir);
-	return rb_sprintf("#<%s:%s>", c, dirp->path);
+	return rb_sprintf("#<%s:%s>", c, RSTRING_PTR(dirp->path));
     }
     return rb_funcall(dir, rb_intern("to_s"), 0, 0);
 }
@@ -463,8 +467,8 @@ dir_path(VALUE dir)
     struct dir_data *dirp;
 
     Data_Get_Struct(dir, struct dir_data, dirp);
-    if (!dirp->path) return Qnil;
-    return dir_enc_str(rb_str_new2(dirp->path), dirp);
+    if (NIL_P(dirp->path)) return Qnil;
+    return rb_str_dup(dirp->path);
 }
 
 /*
-- 
[田中 哲][たなか あきら][Tanaka Akira]