Bug #20348: Memory leak with method kwargs in ERB template

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin23]
• Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN

[davidtaylorhq (David Taylor)]

Evaluating ERB templates with kwarg method calls leads to unbounded growth in memory use.

Example script:

require "erb"

def noop(kwarg1:); end

template = ERB.new("<%= noop kwarg1: false %>")

50.times do
  10_000.times do
    template.result(binding)
  end
  GC.start;
  puts "Object Count: #{ObjectSpace.count_objects[:TOTAL]}"
end

When run, this script will print something like:

Object Count: 53825
Object Count: 80432
Object Count: 105811
Object Count: 137331
Object Count: 179491
Object Count: 179491
Object Count: 236389
...

This issue does not occur when the keyword argument is replaced with a positional argument.

I can reproduce the issue using Ruby 3.0.6, 3.1.4, 3.2.3 and 3.3.0.

The issue does not reproduce using Ruby 2.7.8.

[jeremyevans0 (Jeremy Evans)]

This has been fixed in the master branch. However, I'm not sure which commit fixed it.

[byroot (Jean Boussier)]

I suspect it's https://github.com/ruby/ruby/pull/9973, trying to confirm.

[byroot (Jean Boussier)]

• Status changed from Open to Closed

Confirmed, this is a duplicate of [Bug #19907]. I'll make that one for backport.

[byroot (Jean Boussier)]

• Related to Bug #19907: Method calls with keyword arguments in eval leaks callcache and callinfo objects added