Issue #9087 has been reported by mg (Dawid Grzesiak).

----------------------------------------
Bug #9087: swallowing "s" letters when "i" flag is on
https://bugs.ruby-lang.org/issues/9087

Author: mg (Dawid Grzesiak)
Status: Open
Priority: Low
Assignee: 
Category: regexp
Target version: 
ruby -v: ruby 2.0.0p0 (2013-02-24 revision 39474) [i686-linux]
Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN


# This regexp is removing 's' characters from the string
irb(main):091:0> "fdsa-f fdas5_-423432".gsub /[_\W]/i, ''
=> "fdaffda5423432"

# While this is not:
irb(main):092:0> "fdsa-f fdas5_-423432".gsub /[_\W]/, ''
=> "fdsaffdas5423432"
irb(main):093:0> "fdsa-f fdas5_-423432".gsub /[^0-9a-z]/i, ''
=> "fdsaffdas5423432"


-- 
http://bugs.ruby-lang.org/