Endless loop on mutually recursive renders

[akimd]

Background

Brakeman version: 4.10.0
Rails version: 6.0.3.4
Ruby version: 2.5.7

Issue

We use partials that render partials, and this can be "recursive". Of course there are dynamic conditions for the calls to stop at some point, but statically, Brakeman does not see them and endlessly stacks calls:

For instance

$ grep 'render.*filters_list' app/views/*/_query_builder_filters_list.html.erb 
app/views/accesses/_query_builder_filters_list.html.erb:<%= render partial: '/profile_accesses/query_builder_filters_list' %>
...
app/views/profile_accesses/_query_builder_filters_list.html.erb:<%= render partial: '/accesses/query_builder_filters_list' %>

Other Error

Run Brakeman with --debug to see the full stack trace.

Rendering /accesses/_query_builder_filters_list (["Template:access_rules/_query_builder_filters_list"])
Rendering /profile_accesses/_query_builder_filters_list (["Template:access_rules/_query_builder_filters_list", "Template:accesses/_query_builder_filters_list"])
Rendering /accesses/_query_builder_filters_list (["Template:access_rules/_query_builder_filters_list", "Template:accesses/_query_builder_filters_list", "Template:profile_accesses/_query_builder_filters_list"])
Rendering /profile_accesses/_query_builder_filters_list (["Template:access_rules/_query_builder_filters_list", "Template:accesses/_query_builder_filters_list", "Template:profile_accesses/_query_builder_filters_list", "Template:accesses/_query_builder_filters_list"])
Rendering /accesses/_query_builder_filters_list (["Template:access_rules/_query_builder_filters_list", "Template:accesses/_query_builder_filters_list", "Template:profile_accesses/_query_builder_filters_list", "Template:accesses/_query_builder_filters_list", "Template:profile_accesses/_query_builder_filters_list"])
Rendering /profile_accesses/_query_builder_filters_list (["Template:access_rules/_query_builder_filters_list", "Template:accesses/_query_builder_filters_list", "Template:profile_accesses/_query_builder_filters_list", "Template:accesses/_query_builder_filters_list", "Template:profile_accesses/_query_builder_filters_list", "Template:accesses/_query_builder_filters_list"])
Rendering /accesses/_query_builder_filters_list (["Template:access_rules/_query_builder_filters_list", "Template:accesses/_query_builder_filters_list", "Template:profile_accesses/_query_builder_filters_list", "Template:accesses/_query_builder_filters_list", "Template:profile_accesses/_query_builder_filters_list", "Template:accesses/_query_builder_filters_list", "Template:profile_accesses/_query_builder_filters_list"])
...

Stack trace:

Traceback (most recent call last):
	11282: from /opt/ruby/bin/brakeman:23:in `<main>'
	11281: from /opt/ruby/bin/brakeman:23:in `load'
	11280: from /opt/ruby-2.5.7/lib/ruby/gems/2.5.0/gems/brakeman-4.10.0/bin/brakeman:10:in `<top (required)>'
	11279: from /opt/ruby-2.5.7/lib/ruby/gems/2.5.0/gems/brakeman-4.10.0/lib/brakeman/commandline.rb:20:in `start'
	11278: from /opt/ruby-2.5.7/lib/ruby/gems/2.5.0/gems/brakeman-4.10.0/lib/brakeman/commandline.rb:35:in `run'
	11277: from /opt/ruby-2.5.7/lib/ruby/gems/2.5.0/gems/brakeman-4.10.0/lib/brakeman/commandline.rb:166:in `run_report'
	11276: from /opt/ruby-2.5.7/lib/ruby/gems/2.5.0/gems/brakeman-4.10.0/lib/brakeman/commandline.rb:125:in `regular_report'
	11275: from /opt/ruby-2.5.7/lib/ruby/gems/2.5.0/gems/brakeman-4.10.0/lib/brakeman/commandline.rb:157:in `run_brakeman'
	 ... 11270 levels...
	    4: from /opt/ruby-2.5.7/lib/ruby/gems/2.5.0/gems/brakeman-4.10.0/bundle/ruby/2.7.0/gems/sexp_processor-4.15.1/lib/sexp.rb:65:in `map'
	    3: from /opt/ruby-2.5.7/lib/ruby/gems/2.5.0/gems/brakeman-4.10.0/bundle/ruby/2.7.0/gems/sexp_processor-4.15.1/lib/sexp.rb:65:in `map'
	    2: from /opt/ruby-2.5.7/lib/ruby/gems/2.5.0/gems/brakeman-4.10.0/lib/ruby_parser/bm_sexp.rb:592:in `block in inspect'
	    1: from /opt/ruby-2.5.7/lib/ruby/gems/2.5.0/gems/brakeman-4.10.0/lib/ruby_parser/bm_sexp.rb:590:in `inspect'
/opt/ruby-2.5.7/lib/ruby/gems/2.5.0/gems/brakeman-4.10.0/bundle/ruby/2.7.0/gems/sexp_processor-4.15.1/lib/sexp.rb:65:in `map': stack level too deep (SystemStackError)

Cheers!

[presidentbeef]

Interesting... this was definitely addressed in the past so I'll have to see why the loop detection is not working in this case.

[presidentbeef]

Ah... I think it's the / in the partial name that's evading the loop detection.

[akimd]

Great news, thank!