[polari/wip/fmuellner/fix-regex-lockup: 3/3] utils: Simplify URL regex to only support one layer of parentheses

[Florian Müllner <fmuellner src gnome org>]

commit ecb171a1f85b91edb2e455307de955519810cbf1
Author: Florian Müllner <fmuellner gnome org>
Date:   Sat Feb 24 23:52:39 2018 +0100

    utils: Simplify URL regex to only support one layer of parentheses
    
    The author of the original URL-matching regex warns[0] that the pattern may
    cause certain regex engines to lock up with certain input, namely patterns
    that contain parentheses. It turns out SpiderMonkey is affected, but rather
    than switching to the author's improved version (that is still crazy), sim-
    plify the pattern a bit by removing support for nested parentheses in URLs.
    Even a single pair of parentheses is extremely rare, so this is unlikely to
    make a noticeable difference (other than not locking up SpiderMonkey of
    course) ...
    
    [0] http://daringfireball.net/2010/07/improved_regex_for_matching_urls
    
    https://gitlab.gnome.org/GNOME/polari/issues/46

 src/utils.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/utils.js b/src/utils.js
index 6c381a0..ea1f75e 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -49,7 +49,7 @@ const MAX_PASTE_TITLE_LENGTH = 25;
 const IMGUR_CLIENT_ID = '4109e59177ec95e';
 
 // http://daringfireball.net/2010/07/improved_regex_for_matching_urls
-const _balancedParens = '\\((?:[^\\s()<>]+|(?:\\(?:[^\\s()<>]+\\)))*\\)';
+const _balancedParens = '\\([^\\s()<>]+\\)';
 const _leadingJunk = '[\\s`(\\[{\'\\"<\u00AB\u201C\u2018]';
 const _notTrailingJunk = '[^\\s`!()\\[\\]{};:\'\\".,<>?\u00AB\u00BB\u201C\u201D\u2018\u2019]';