Hello,
I''ve run into a bug with the implementation of gsub in
https://github.com/rails/rails/blob/master/activesupport/lib/active_support/core_ext/string/output_safety.rb
My code is essentially this... (my pattern captures values to the
global variables $1, $2)
text.gsub(pattern) do |match|
# uses match, $1, $2
end
When running this, my match var is passed correctly, but $1 and $2 are
nil. If I remove gsub from the list of UNSAFE_STRING_METHODS gsub
works as expected, so gsub is currently broken in Rails as far as I
can see.
To test this you can do the following (do this in Rails 3-1... Rails
3-0 gsub is broken even more right now)...
Broken (using SafeBuffer)...
ruby-1.9.2-p290 :001 > ActiveSupport::SafeBuffer.new("capture
this").gsub(/(capture) (this)/){|match| p match, $1, $2}
"capture this"
nil
nil
Good (using String)...
ruby-1.9.2-p290 :004 > String.new("capture this").gsub(/(capture)
(this)/){|match| p match, $1, $2}
"capture this"
"capture"
"this"
Basically the current code doesn''t persist the values of the globals
$1, $2, etc.
def #{unsafe_method}(*args, &block) # def gsub(*args, &block)
to_str.#{unsafe_method}(*args, &block)
end
I did some testing to rewrite this method and $1 and $2 are in fact
set in the overridden method, but they are nil inside the block of the
method outside of the override. The actual fix for this is somewhat
beyond my knowledge of ruby, as I thought global variables would
remain global, but something else is going on here. I read that some
of the special global vars are in fact treated as locals, so I''m not
sure if this is the case here.
Any ideas on how to fix this properly? Suggestions welcome so I can
submit a patch.
Andrew
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There is a discussion about SaffeBuffer#gsub in https://github.com/rails/rails/issues/1555 -- Guillermo Iguaran Sent with Sparrow (http://www.sparrowmailapp.com) On Saturday, August 13, 2011 at 12:42 PM, Andrew Kaspick wrote:> Hello, > > I''ve run into a bug with the implementation of gsub in > https://github.com/rails/rails/blob/master/activesupport/lib/active_support/core_ext/string/output_safety.rb > > My code is essentially this... (my pattern captures values to the > global variables $1, $2) > > text.gsub(pattern) do |match| > # uses match, $1, $2 > end > > When running this, my match var is passed correctly, but $1 and $2 are > nil. If I remove gsub from the list of UNSAFE_STRING_METHODS gsub > works as expected, so gsub is currently broken in Rails as far as I > can see. > > To test this you can do the following (do this in Rails 3-1... Rails > 3-0 gsub is broken even more right now)... > > Broken (using SafeBuffer)... > ruby-1.9.2-p290 :001 > ActiveSupport::SafeBuffer.new("capture > this").gsub(/(capture) (this)/){|match| p match, $1, $2} > "capture this" > nil > nil > > Good (using String)... > ruby-1.9.2-p290 :004 > String.new("capture this").gsub(/(capture) > (this)/){|match| p match, $1, $2} > "capture this" > "capture" > "this" > > Basically the current code doesn''t persist the values of the globals > $1, $2, etc. > > def #{unsafe_method}(*args, &block) # def gsub(*args, &block) > to_str.#{unsafe_method}(*args, &block) > end > > I did some testing to rewrite this method and $1 and $2 are in fact > set in the overridden method, but they are nil inside the block of the > method outside of the override. The actual fix for this is somewhat > beyond my knowledge of ruby, as I thought global variables would > remain global, but something else is going on here. I read that some > of the special global vars are in fact treated as locals, so I''m not > sure if this is the case here. > > Any ideas on how to fix this properly? Suggestions welcome so I can > submit a patch. > > Andrew > > -- > You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. > To post to this group, send email to rubyonrails-core@googlegroups.com (mailto:rubyonrails-core@googlegroups.com). > To unsubscribe from this group, send email to rubyonrails-core+unsubscribe@googlegroups.com (mailto:rubyonrails-core+unsubscribe@googlegroups.com). > For more options, visit this group at http://groups.google.com/group/rubyonrails-core?hl=en.-- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. To post to this group, send email to rubyonrails-core@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-core+unsubscribe@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-core?hl=en.
Ah, thanks. Glad to see it''s being worked on. I should have searched the issues first. I''ll use my work around of using String.new(text) to force the standard gsub usage. Thanks again On Sat, Aug 13, 2011 at 12:46 PM, Guillermo Iguaran <guilleiguaran@gmail.com> wrote:> There is a discussion about SaffeBuffer#gsub > in https://github.com/rails/rails/issues/1555 > > -- > Guillermo Iguaran > Sent with Sparrow > > On Saturday, August 13, 2011 at 12:42 PM, Andrew Kaspick wrote: > > Hello, > > I''ve run into a bug with the implementation of gsub in > https://github.com/rails/rails/blob/master/activesupport/lib/active_support/core_ext/string/output_safety.rb > > My code is essentially this... (my pattern captures values to the > global variables $1, $2) > > text.gsub(pattern) do |match| > # uses match, $1, $2 > end > > When running this, my match var is passed correctly, but $1 and $2 are > nil. If I remove gsub from the list of UNSAFE_STRING_METHODS gsub > works as expected, so gsub is currently broken in Rails as far as I > can see. > > To test this you can do the following (do this in Rails 3-1... Rails > 3-0 gsub is broken even more right now)... > > Broken (using SafeBuffer)... > ruby-1.9.2-p290 :001 > ActiveSupport::SafeBuffer.new("capture > this").gsub(/(capture) (this)/){|match| p match, $1, $2} > "capture this" > nil > nil > > Good (using String)... > ruby-1.9.2-p290 :004 > String.new("capture this").gsub(/(capture) > (this)/){|match| p match, $1, $2} > "capture this" > "capture" > "this" > > Basically the current code doesn''t persist the values of the globals > $1, $2, etc. > > def #{unsafe_method}(*args, &block) # def gsub(*args, &block) > to_str.#{unsafe_method}(*args, &block) > end > > I did some testing to rewrite this method and $1 and $2 are in fact > set in the overridden method, but they are nil inside the block of the > method outside of the override. The actual fix for this is somewhat > beyond my knowledge of ruby, as I thought global variables would > remain global, but something else is going on here. I read that some > of the special global vars are in fact treated as locals, so I''m not > sure if this is the case here. > > Any ideas on how to fix this properly? Suggestions welcome so I can > submit a patch. > > Andrew > > -- > You received this message because you are subscribed to the Google Groups > "Ruby on Rails: Core" group. > To post to this group, send email to rubyonrails-core@googlegroups.com. > To unsubscribe from this group, send email to > rubyonrails-core+unsubscribe@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/rubyonrails-core?hl=en. > > -- > You received this message because you are subscribed to the Google Groups > "Ruby on Rails: Core" group. > To post to this group, send email to rubyonrails-core@googlegroups.com. > To unsubscribe from this group, send email to > rubyonrails-core+unsubscribe@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/rubyonrails-core?hl=en. >-- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. To post to this group, send email to rubyonrails-core@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-core+unsubscribe@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-core?hl=en.