Issue #5322 has been reported by Rasmus Rønn Nielsen.

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Bug #5322: URI.decode_www_form_component very slow with certain inputs
http://redmine.ruby-lang.org/issues/5322

Author: Rasmus Rønn Nielsen
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 1.9.2
ruby -v: ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin11.0.1]


When calling the following I get what I'd expect. An error.

 URI.decode_www_form_component("aaaaaaaaaaaaaaaaaaaa%")

Here's the IRB output:

 ruby-1.9.2-p290 :003 > URI.decode_www_form_component("aaaaaaaaaaaaaaaaaaaa%")
 ArgumentError: invalid %-encoding (aaaaaaaaaaaaaaaaaaaa%)
 from /Users/rasmus/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/uri/common.rb:778:in `decode_www_form_component'
 from (irb):3
 rom /Users/rasmus/.rvm/rubies/ruby-1.9.2-p290/bin/irb:16:in `<main>'

But as I add more characters to the string, the execution becomes much much slower. I would expect it to be a lot faster than it is.

 URI.decode_www_form_component("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa%")

Add more characters and the call would take hours, if not days.

Related blog post: http://rrn.dk/running-ruby-process-callstack

I've reproduced this bug on these rubies:
ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin11.0.1]
ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-linux]



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