From: naruse@...
Date: 2017-03-22T13:27:35+00:00
Subject: [ruby-dev:50033] [Ruby trunk Bug#13352][Rejected] RegExp infinite	looping

Issue #13352 has been updated by naruse (Yui NARUSE).

Status changed from Open to Rejected

323字目の * を削ってください。
```
(?=\W)\W?(?:(?:(?:\/\*<)?[\'\"]?([\w_\$]+)[\'\"]?(?:>\*\/\s+this)?|(this))\.(\$scope|json)|([\'\"](?:\$scope|json)[\'\"]))((\.)(inputObjects)|(\.)(spreadSheets)(?:\.[\'\"]?([^\.\'\"\|\s,]+)[\'\"]?|\[[\'\"]?((?:[^\'\"\]\[]*|\[[^\]]*\])*)[\'\"]?\])(\.)(model))\s*(?:\.[\'\"]?([^\.\'\"\|\s,]+)[\'\"]?|\[[\'\"]?((?:[^\'\"\]\[]|\[[^\]]*\])*)[\'\"]?\])
```

正規表現の解析には例えば以下のサイトを使うことが出来ます。
https://regex101.com/

この類の正規表現を検出するのはトレードオフがあるのでRubyもnodeも標準では難しいと思いますが、
nodeならば例えば https://github.com/uhop/node-re2 だとこの問題を回避できます。

----------------------------------------
Bug #13352: RegExp infinite looping
https://bugs.ruby-lang.org/issues/13352#change-63730

* Author: jumnichi_kose (小瀬 淳一)
* Status: Rejected
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: 2.3.3p222 (2016-11-21 revision 56859) [x64-mingw32],  ruby 2.2.4p230 (2015-12-16 revision 53155) [i386-mingw32]
* Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN
----------------------------------------
ruby entered an infinite loop with the following three steps.

~~~ ruby
r = /(?=\W)\W?(?:(?:(?:\/\*<)?[\'\"]?([\w_\$]+)[\'\"]?(?:>\*\/\s+this)?|(this))\.(\$scope|json)|([\'\"](?:\$scope|json)[\'\"]))((\.)(inputObjects)|(\.)(spreadSheets)(?:\.[\'\"]?([^\.\'\"\|\s,]+)[\'\"]?|\[[\'\"]?((?:[^\'\"\]\[]*|\[[^\]]*\])*)[\'\"]?\])(\.)(model))\s*(?:\.[\'\"]?([^\.\'\"\|\s,]+)[\'\"]?|\[[\'\"]?((?:[^\'\"\]\[]*|\[[^\]]*\])*)[\'\"]?\])/
txt = ".model |,| 'anController'.$scope.inputObjects['fieldName .../* !! comment ...*/"
txt.scan r
~~~

Node.js also falls into an infinite loop.
~~~ javascript
var r = /(?=\W)\W?(?:(?:(?:\/\*<)?[\'\"]?([\w_\$]+)[\'\"]?(?:>\*\/\s+this)?|(this))\.(\$scope|json)|([\'\"](?:\$scope|json)[\'\"]))((\.)(inputObjects)|(\.)(spreadSheets)(?:\.[\'\"]?([^\.\'\"\|\s,]+)[\'\"]?|\[[\'\"]?((?:[^\'\"\]\[]*|\[[^\]]*\])*)[\'\"]?\])(\.)(model))\s*(?:\.[\'\"]?([^\.\'\"\|\s,]+)[\'\"]?|\[[\'\"]?((?:[^\'\"\]\[]*|\[[^\]]*\])*)[\'\"]?\])/
var txt = ".model |,| 'anController'.$scope.inputObjects['fieldName .../* !! comment ...*/"

var s =r.exec (txt)

console.log(s)


~~~





-- 
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