Issue #13932 has been updated by jeremyevans0 (Jeremy Evans).

Status changed from Open to Closed

This patch appears to change a general behavior of `require` even when extension libraries are not involved.  For example, it changes the behavior of this code:

```ruby
Dir.mkdir('a')
Dir.mkdir('b')
File.write('a/c.rb', '$a = 1')
File.write('b/c.rb', '$a = 2')

$:.unshift('a')
require 'c'
p $a
$:.unshift('b')
require 'c'
p $a
# Before: 2
# With Patch: 1
```

I don't think Ruby's current behavior here is a bug.  `require` will not load the same file path a second time, but it will load a different file path for the same argument if there has been a change to the load path.  The documentation for `require` describes this behavior: `A file will not be loaded again if its path already appears in $"` (saying nothing about the argument to `require`).  As the current behavior does not appear to be a bug, I'm going to close this.

----------------------------------------
Bug #13932: [PATCH] Extension libraries take precedence in checks of later Kernel.#require calls for features without file extensions
https://bugs.ruby-lang.org/issues/13932#change-87525

* Author: akihikodaki (Akihiko Odaki)
* Status: Closed
* Priority: Normal
* ruby -v: ruby 2.5.0dev (2017-09-23 trunk 60002) [x86_64-linux]
* Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN
----------------------------------------
Extension libraries take precedence in checks of later `Kernel.#require` calls for features without file extensions. That behavior is inconsistent with the first call, and can cause problems.

For instance, feature `openssl` has `openssl.rb` and `openssl.so`, but it assumes `openssl.rb` will always be loaded when it gets required. That assumption works for the first call of `Kernel.#require`, but for the later calls, `require` assumes `openssl.so` is being required and checks if the file is valid for the requirement.

Usually that is not so problematic since it just check if `openssl.so`, which is already required by `openssl.rb`, is required or not. However, if there is a new alternative `openssl.rb` in `$:`, the file will be loaded and conflict with the feature already loaded.
The below is a code example.

~~~Ruby
p $:.include? '/usr/lib/ruby/2.4.0' # true
p $:.include? '/home/aki/mastodon/vendor/bundle/ruby/2.4.0/gems/openssl-2.0.5/lib' # false

p $".include? '/usr/lib/ruby/2.4.0/openssl/openssl.rb' # false
p $".include? '/home/aki/mastodon/vendor/bundle/ruby/2.4.0/gems/openssl-2.0.5/lib/openssl.rb' # false

require 'openssl'

p $".include? '/usr/lib/ruby/2.4.0/openssl/openssl.rb' # true
p $".include? '/home/aki/mastodon/vendor/bundle/ruby/2.4.0/gems/openssl-2.0.5/lib/openssl.rb' # false

$:.unshift '/home/aki/mastodon/vendor/bundle/ruby/2.4.0/gems/openssl-2.0.5/lib'
require 'openssl'

p $".include? '/home/aki/mastodon/vendor/bundle/ruby/2.4.0/gems/openssl-2.0.5/lib/openssl.rb' # true (unexpected)
~~~

---Files--------------------------------
load.patch (2.42 KB)


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