Bug #14959
Updated by y4m4p (Masahiro Yamashita) over 6 years ago
# Disclaimer
Sorry about the problem being rails, and not ruby specific. I couldn't narrow down the problem and wording it correctly.
As it turns out that the problem derived from the ruby vm used in my Rails application, I decided to create the issue here.
## Backstory
I have created this issue in rails/rails. (https://github.com/rails/rails/issues/33460)
I became aware that this issue derives from Shopify/bootsnap (https://github.com/Shopify/bootsnap/issues/182)
The member there told me that this is an issue with the ruby vm itself, so I have created this issue here.
Please refer for more information in the above link.
# Reproduction
## Reproduction Project:
https://github.com/y4m4p/rails_issue_33460
## Project Dependency
program version
ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-darwin17]
Rails 5.2.0
Bundler 1.16.1
Mysql 5.7.21 Homebrew
## Reproduction method
~~~ ruby
def helper_method
if true
link_to 'page', some_view_path(foo: 'true')
else
link_to 'somewhere', some_view_path(foo: 'false')
end
end
~~~
### Crash condition
Writing this helper method under "app/helper" directory in Rails which satisfies all of the next particular conditions will crash the Rails server application with
KERN_INVALID_ADDRESS at 0x0000000000000000.
* Writing a condition with
~~~ ruby
if true
...
else
...
~~~
OR
~~~ ruby
if false
...
else
...
~~~
* Write a path using the "link_to" helper and a "url_helper (xxx_path)" which contains a "request parameter" (xxx_path(some_parameter: 'x')).
* Writing the process under the statement that will never be used.
For example, if you write the "if" sentence with "if true" then you must write your process under the "else" statement and vice versa.
### Non crashing condition
* Writing the "if" condition with a instance variable or constant.
~~~ ruby
def helper_method
condition = true
if condition
...
else
...
end
end
~~~
* Do not write the specific "link_to" helper process under the statement that will never be used.
~~~ ruby
def helper_method
if true
link_to 'somewhere', web_pages_some_view_path(foo: 'true')
else
# link_to 'somewhere', web_pages_some_view_path(foo: 'false') <= comment out
end
end
~~~
* Do not write the request parameter for the "url_helper" path.
~~~ ruby
def helper_method
if true
link_to 'somewhere', web_pages_some_view_path(foo: 'true') #<= Writing the request parameter in the used statement is OK
else
link_to 'somewhere', web_pages_some_other_view_path
end
end
~~~
* Do not write the process in helper. But rather, writing the process in the view itself will not crash.
~~~ ruby
# app/view/web_pages/some_view.html.erb
<%= if true
link_to 'somewhere', web_pages_some_view_path(foo: 'true')
else
link_to 'somewhere', web_pages_some_view_path(foo: 'false')
end %>
~~~
## Expected
Should render correct views with link and not crash.
Even though I am writing the "if" condition with "true" which makes the "else" statement useless, but this should work as intended. (Just render the "true" statement.)