[ruby-dev:42069] Re: [Bug #3708] Array#permutation がおかしな結果を返す

まつもと ゆきひろです

In message "Re: [ruby-dev:42068] Re: [Bug #3708] Array#permutation 	がおかしな結果を返す"
    on Wed, 18 Aug 2010 18:16:13 +0900, Kenta Murata <[e-mail]> writes:

|On 2010/08/18, at 16:33, Shumpei Akai wrote:
|
|> Array#permutationの結果に，配列に含まれていないはずの値が入っています
|> 
|> % ./ruby_head -e "p [0,1,2,3,4][1,4].permutation.to_a"
|> [[0, 1, 2, 3], [0, 1, 3, 2], [0, 2, 1, 3], [0, 2, 3, 1], [0, 3, 1, 2], [0, 3, 2, 1], [1, 0, 2, 3], [1, 0, 3, 2], [1, 2, 0, 3], [1, 2, 3, 0], [1, 3, 0, 2], [1, 3, 2, 0], [2, 0, 1, 3], [2, 0, 3, 1], [2, 1, 0, 3], [2, 1, 3, 0], [2, 3, 0, 1], [2, 3, 1, 0], [3, 0, 1, 2], [3, 0, 2, 1], [3, 1, 0, 2], [3, 1, 2, 0], [3, 2, 0, 1], [3, 2, 1, 0]]
|> 
|> 
|> [0,1,2,3,4][1,4] は [1, 2, 3, 4] なので0は含まれないはずです．
|> 
|> 
|> % ./ruby_head -e "p [0,1,2,3][1,3].permutation.to_a"
|> だと正しく動きます
|
|
|ary_make_shared 関数を以下のように修正すると正常に動作します。
|
|diff --git a/array.c b/array.c
|index 51d3ad2..ea4fe43 100644
|--- a/array.c
|+++ b/array.c
|@@ -409,10 +409,7 @@ static VALUE
| ary_make_shared(VALUE ary)
| {
|     assert(!ARY_EMBED_P(ary));
|-    if (ARY_SHARED_P(ary)) {
|-       return ARY_SHARED(ary);
|-    }
|-    else if (ARY_SHARED_ROOT_P(ary)) {
|+    if (ARY_SHARED_P(ary) || ARY_SHARED_ROOT_P(ary)) {
|        return ary;
|     }
|     else if (OBJ_FROZEN(ary)) {

なるほど。コミットして下さい。