#

You can add this current_url method in the ApplicationController to return the current URL and allow merging in other parameters

# https://x.com/y/1?page=1 
# + current_url( :page => 3 )
# = https://x.com/y/1?page=3
def current_url(overwrite={})
    url_for :only_path => false, :params => params.merge(overwrite)
end
Example Usage:

current_url --> http://...
current_url(:page=>4) --> http://...&page=4

So I used request.env["HTTP_REFERER"] which stores the URL of the last reloaded request.

Here's an excerpt from the partial to make a decision

- if request.env["HTTP_REFERER"].to_s.scan("history").length > 0
  - back_url = user_history_issue_path(@user, list: "needed_type")
- else
  - back_url = user_needed_type_issue_path(@user)
- remote ||= false
=link_to t("static.back"), back_url, :remote => remote

request.original_url
or
request.env["HTTP_REFERER"]
or
request.env['REQUEST_URI']

How about sending signal to the ruby process, and creating a handler for the signal which dumps all stacks?

From http://le-huy.blogspot.com/2012/04/dump-backtrace-of-all-threads-in-ruby.html we have this example :

require 'pp'

def backtrace_for_all_threads(signame)
  File.open("/tmp/ruby_backtrace_#{Process.pid}.txt","a") do |f|
      f.puts "--- got signal #{signame}, dump backtrace for all threads at #{Time.now}"
      if Thread.current.respond_to?(:backtrace)
        Thread.list.each do |t|
          f.puts t.inspect
          PP.pp(t.backtrace.delete_if {|frame| frame =~ /^#{File.expand_path(__FILE__)}/},
               f) # remove frames resulting from calling this method
        end
      else
          PP.pp(caller.delete_if {|frame| frame =~ /^#{File.expand_path(__FILE__)}/},
               f) # remove frames resulting from calling this method
      end
  end
end

Signal.trap(29) do
  backtrace_for_all_threads("INFO")
end
Then we need to send the signal to the appropriate process :

ps afxw | grep ruby
kill -29 <pid>
ls -l /tmp/ruby*
vi /tmp/ruby_backtrace_...

You can throw an exception at any time, and then look at the $@ predefined variable, which returns an array of backtrace data. E.g. put this in foo.rb:

begin                                                                        
  raise 'foo'                                                                
rescue                                                                       
  puts $@                                                                    
end