# \[Bug #1198\] corrupted iteratoin during "enum\_for :inject"

**URL:** <https://www.ruby-forum.com/t/bug-1198-corrupted-iteratoin-during-enum-for-inject/161200>\
**Category:** Development\
**Created:** [February 24, 2009, 9:14am UTC](https://www.ruby-forum.com/t/bug-1198-corrupted-iteratoin-during-enum-for-inject/161200 "2009-02-24T09:14:18Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![Shyouhei\_U](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/94ad74/32.png) [@Shyouhei\_U](https://www.ruby-forum.com/u/Shyouhei_U)\
**Post date:** [February 24, 2009, 9:14am UTC](https://www.ruby-forum.com/t/bug-1198-corrupted-iteratoin-during-enum-for-inject/161200/1 "2009-02-24T09:14:18Z")

</div>

Bug #1198: corrupted iteratoin during “enum\_for :inject”  
[http://redmine.ruby-lang.org/issues/show/1198](http://redmine.ruby-lang.org/issues/show/1198)

e$B5/I\<\<Te(B: Shyouhei U.  
e$B%9%F!\<%?%9e(B: Open, e$BM%@hEYe(B: Normal  
e$B%+%F%4%je(B: core  
ruby -v: ruby 1.9.2dev (2009-02-24 trunk 22589) [x86\_64-linux]

e$B0J2\<$N$h$&$K!"e(B1.8e$B$He(B1.9e$B$Ge(Benum\_for(:inject)e$B$7$?$H$-$N?6$kIq$$$,0c$&$h$&$G$9!#e(B

zsh % ruby -ve ‘[:x].enum\_for(:inject, :y).with\_index {|\*a| p a }’  
ruby 1.8.7p5000 (2009-02-24 revision 22586) [x86\_64-linux]  
[[:y, :x], 0]

zsh % ruby -ve ‘[:x].enum\_for(:inject, :y).with\_index {|\*a| p a }’  
ruby 1.9.2dev (2009-02-24 trunk 22589) [x86\_64-linux]  
[:y, 0]

---

<div class="post-metadata">

**Author:** ![Shyouhei\_U](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/94ad74/32.png) [@Shyouhei\_U](https://www.ruby-forum.com/u/Shyouhei_U)\
**Post date:** [February 24, 2009, 11:31am UTC](https://www.ruby-forum.com/t/bug-1198-corrupted-iteratoin-during-enum-for-inject/161200/2 "2009-02-24T11:31:16Z")

</div>

e$B%A%1%C%He(B #1198 e$B$,99?7$5$l$^$7$?!#e(B (by Akinori MUSHA)

e$B%U%!%$%ke(B with\_index-compat.patch e$BDI2Ce(B

e$B?6$kIq$$$,0c$&$N$Oe(B (each\_)with\_index e$B$NJ}$G$9!#e(B  
1.9e$B$G$O!“%$%F%l!\<%?4X?t$NBh0l0z?t$K$O:G=i$N0z?t$@$1$,EO$k$h$&$K$J$j!“e(B  
e$BB?CM$r\<h$j$?$1$l$PBh;0Bh;M0z?t$Ge(Bargc/argve$B$r8+$kI,MW$,$”$j$^$9!#e(B  
e$B$3$NJQ99$KBP1~$9$kJQ99$,;$5$l$F$$$J$$$?$a!”$=$N$h$&$J5sF0$K$J$C$F$$$^$9!#e(B

## e$BC1$Ke(B1.8e$B$HF1$8$h$&$K?6$kIq$o$;$k$?$a$K$OE:IU$N%Q%C%A$G$$$$$O$:$G$9!#e(B

[http://redmine.ruby-lang.org/issues/show/1198](http://redmine.ruby-lang.org/issues/show/1198)

---

<div class="post-metadata">

**Author:** ![Shyouhei\_U](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/94ad74/32.png) [@Shyouhei\_U](https://www.ruby-forum.com/u/Shyouhei_U)\
**Post date:** [February 24, 2009, 11:56am UTC](https://www.ruby-forum.com/t/bug-1198-corrupted-iteratoin-during-enum-for-inject/161200/3 "2009-02-24T11:56:00Z")

</div>

e$B%A%1%C%He(B #1198 e$B$,99?7$5$l$^$7$?!#e(B (by Akinori MUSHA)

e$B%U%!%$%ke(B with\_index-incompat.patch e$BDI2Ce(B

e$B$?$@!"$3$N\>l9gJ,$1$Oe(B1.9e$B$G@0M}$7$?C1CM!&B?CM$N07$$$N0l4S@-$rJx$9$3$H$K$b$J$k$N$Ge(B  
e$B$b$&\>/$79M$($?J}$,$$$$$H;W$$$^$9!#e(B

with\_index-compat.patch e$B$NDL$j!"e(B1.8e$B$G$O!"e(B

- yield() e$B$5$l$?$ie(B yield(nil, idx) e$B$9$ke(B
- yield(single) e$B$5$l$?$ie(B yield(single, idx) e$B$9$ke(B
- yield(\*multiple) e$B$5$l$?$ie(B yield(multiple, idx) e$B$9$ke(B

e$B$H$$$&$$$S$D$J;EMM$G!“C1CM$+B?CM$+$rCN$C$F$$$J$$$H@5$7$$%3!\<%I$,=q$1$J$$\>l9g$,$”$j$^$9!#e(B

1.9e$B$G$Oe(B { |\*args, idx| … } e$B$H\<u$1\<h$jJ}$,$G$-$k$N$G!"C1$Ke(B

- yield(\*any) e$B$5$l$?$ie(B yield(\*any, idx) e$B$9$ke(B

e$B$H$$$&$9$C$-$j$7$?;EMM$KJQ99$9$k$H$$$&A\*Br;h$b==J,$K9M$($i$l$^$9!#e(B

## e$B8\_49@-$,:GBg$N\>c32$G$9$1$I$M!D!#e(B

[http://redmine.ruby-lang.org/issues/show/1198](http://redmine.ruby-lang.org/issues/show/1198)

---

<div class="post-metadata">

**Author:** ![Shyouhei\_U](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/94ad74/32.png) [@Shyouhei\_U](https://www.ruby-forum.com/u/Shyouhei_U)\
**Post date:** [February 24, 2009, 11:40am UTC](https://www.ruby-forum.com/t/bug-1198-corrupted-iteratoin-during-enum-for-inject/161200/4 "2009-02-24T11:40:03Z")

</div>

e$B$^$D$b$He(B e$B$f$-$R$m$G$9e(B

In message “Re: [ruby-dev:38076] [Bug #1198] corrupted iteratoin during  
“enum\_for :inject””  
on Tue, 24 Feb 2009 19:29:44 +0900, Akinori MUSHA  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|e$B?6$kIq$$$,0c$&$N$Oe(B (each\_)with\_index e$B$NJ}$G$9!#e(B  
|1.9e$B$G$O!“%$%F%l!\<%?4X?t$NBh0l0z?t$K$O:G=i$N0z?t$@$1$,EO$k$h$&$K$J$j!“e(B  
|e$BB?CM$r\<h$j$?$1$l$PBh;0Bh;M0z?t$Ge(Bargc/argve$B$r8+$kI,MW$,$”$j$^$9!#e(B  
|e$B$3$NJQ99$KBP1~$9$kJQ99$,;$5$l$F$$$J$$$?$a!”$=$N$h$&$J5sF0$K$J$C$F$$$^$9!#e(B  
|  
|e$BC1$Ke(B1.8e$B$HF1$8$h$&$K?6$kIq$o$;$k$?$a$K$OE:IU$N%Q%C%A$G$$$$$O$:$G$9!#e(B

e$B%3%\_%C%H$7$F$/$@$5$$!#e(B

---

<div class="post-metadata">

**Author:** ![Shyouhei\_U](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/94ad74/32.png) [@Shyouhei\_U](https://www.ruby-forum.com/u/Shyouhei_U)\
**Post date:** [March 13, 2009, 11:52am UTC](https://www.ruby-forum.com/t/bug-1198-corrupted-iteratoin-during-enum-for-inject/161200/5 "2009-03-13T11:52:03Z")

</div>

e$B$^$D$b$He(B e$B$f$-$R$m$G$9e(B

In message “Re: [ruby-dev:38078] [Bug #1198] corrupted iteratoin during  
“enum\_for :inject””  
on Tue, 24 Feb 2009 19:53:59 +0900, Akinori MUSHA  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|e$B%U%!%$%ke(B with\_index-incompat.patch e$BDI2Ce(B  
|  
|e$B$?$@!"$3$N\>l9gJ,$1$Oe(B1.9e$B$G@0M}$7$?C1CM!&B?CM$N07$$$N0l4S@-$rJx$9$3$H$K$b$J$k$N$Ge(B  
|e$B$b$&\>/$79M$($?J}$,$$$$$H;W$$$^$9!#e(B

e$B$&!\<$`!#e(B

|1.9e$B$G$Oe(B { |\*args, idx| … } e$B$H\<u$1\<h$jJ}$,$G$-$k$N$G!"C1$Ke(B  
|  
|- yield(\*any) e$B$5$l$?$ie(B yield(_any, idx) e$B$9$ke(B  
|  
|e$B$H$$$&$9$C$-$j$7$?;EMM$KJQ99$9$k$H$$$&A_Br;h$b==J,$K9M$($i$l$^$9!#e(B

e$B$J$k$[$I!#e(B

|e$B8\_49@-$,:GBg$N\>c32$G$9$1$I$M!D!#e(B

e$B$^$:8=:\_$Ne(B1.9.1e$B$N5sF0$OL@$i$+$K%P%0$J$N$G=$@5$9$kI,MW$,$“$ke(B  
e$B$H;W$$$^$9!#$=$l$r$I$NJ}8~$KD\>$9$+$G$9$,!”$3$3$OHs8\_49$G$b$9$Ce(B  
e$B$-$j$7$?=$@5$NJ}$,K\>$^$7$$$N$G$O$J$$$G$7$g$&$+!#e(B

e$BIp\<T$5$s$,%3%\_%C%H$5$l$^$9$+!)e(B

```
                            e$B$^$D$b$He(B e$B$f$-$R$me(B /:|)

```

---

<div class="post-metadata">

**Author:** ![Shyouhei\_U](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/94ad74/32.png) [@Shyouhei\_U](https://www.ruby-forum.com/u/Shyouhei_U)\
**Post date:** [March 17, 2009, 10:17am UTC](https://www.ruby-forum.com/t/bug-1198-corrupted-iteratoin-during-enum-for-inject/161200/6 "2009-03-17T10:17:36Z")

</div>

e$B%A%1%C%He(B #1198 e$B$,99?7$5$l$^$7$?!#e(B (by Akinori MUSHA)

e$B%9%F!\<%?%9e(B Opene$B$+$ie(BClosede$B$KJQ99e(B  
e$B?JD=e(B % 0e$B$+$ie(B100e$B$KJQ99e(B

## Applied in changeset r22992.

[http://redmine.ruby-lang.org/issues/show/1198](http://redmine.ruby-lang.org/issues/show/1198)

---

<div class="post-metadata">

**Author:** ![Shyouhei\_U](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/94ad74/32.png) [@Shyouhei\_U](https://www.ruby-forum.com/u/Shyouhei_U)\
**Post date:** [March 17, 2009, 9:52am UTC](https://www.ruby-forum.com/t/bug-1198-corrupted-iteratoin-during-enum-for-inject/161200/7 "2009-03-17T09:52:58Z")

</div>

At Fri, 13 Mar 2009 19:47:54 +0900,  
matz wrote:

> |1.9では { |\*args, idx| … } と受け取り方ができるので、単に  
> と思います。それをどの方向に直すかですが、ここは非互換でもすっ  
> きりした修正の方が望ましいのではないでしょうか。

　Enumerator#each\_with\_index については明らかなバグと言える挙動  
だったのですが、 Enumerable#each\_with\_index は1.8と同じ仕様で  
動いていたことがわかりました。

% ruby-1.9.1 -e ‘Enumerator.new{|y| y.yield(); y.yield(1); y.yield(1,2)  
}.to\_a.each\_with\_index {|\*x| p x}’  
[nil, 0]  
[1, 1]  
[[1, 2], 2]

この両者で挙動が食い違うわけにもいかないので、少なくとも1.9系列は  
1.8仕様で行くしかなさそうです。

　ただし、 with\_index のみ変えるというのはありかもしれません。  
いや、そんな違いはわかりにくいからなしかな…。