File::Stat#directory? returns false for symlink to directory with trailing slash

[janko]

Environment

$ jruby -v
jruby 9.2.5.0 (2.5.0) 2018-12-06 6d5a228 Java HotSpot(TM) 64-Bit Server VM 25.40-b25 on 1.8.0_40-b27 +jit [darwin-x86_64]

$ uname -a
Darwin Jankos-MacBook-Pro-2.local 18.2.0 Darwin Kernel Version 18.2.0: Fri Oct  5 19:41:49 PDT 2018; root:xnu-4903.221.2~2/RELEASE_X86_64 x86_64

Expected behaviour

In MRI, when a Pathname instance points to a symlink, Pathname#find will follow the symlink if you add a trailing slash. To illustrate, this script:

require "pathname"
require "tmpdir"
require "fileutils"

source_path = "#{Dir.tmpdir}/foo"
link_path   = "#{Dir.tmpdir}/foo-symlink"

FileUtils.rm_rf(source_path)
FileUtils.mkdir(source_path)
FileUtils.touch("#{source_path}/file")

FileUtils.rm_f(link_path)
FileUtils.ln_s(source_path, link_path)

Pathname(link_path).find { |path| p path }
puts "===="
Pathname("#{link_path}/").find { |path| p path }

will output the following on MRI:

#<Pathname:/var/folders/k7/6zx6dx6x7ys3rv3srh0nyfj00000gn/T/foo-symlink>
====
#<Pathname:/var/folders/k7/6zx6dx6x7ys3rv3srh0nyfj00000gn/T/foo-symlink/>
#<Pathname:/var/folders/k7/6zx6dx6x7ys3rv3srh0nyfj00000gn/T/foo-symlink/file>

Actual behaviour

JRuby won't follow the symlink on trailing slash:

<Pathname:/var/folders/k7/6zx6dx6x7ys3rv3srh0nyfj00000gn/T/foo-symlink>
====
<Pathname:/var/folders/k7/6zx6dx6x7ys3rv3srh0nyfj00000gn/T/foo-symlink/>

[janko]

I managed to narrow it down to the discrepancy in File::Stat#directory? when referencing symlinks. This script:

require "tmpdir"
require "fileutils"

source_path = "#{Dir.tmpdir}/foo"
link_path   = "#{Dir.tmpdir}/foo-symlink"

FileUtils.mkdir_p(source_path)
FileUtils.ln_s(source_path, link_path, force: true)

puts File.lstat(link_path).directory?
puts File.lstat("#{link_path}/").directory?

outputs on MRI:

false
true

but on JRuby it outputs:

false
false

[nomadium]

Thanks for narrowing down the issue. I could reproduce this issue in the master branch with MacOS (10.13.3) and with Linux (Debian unstable).

[enebo]

@janko I merged @nomadium patch. Can you try jruby-head and verify this is fixed for you? I am closing as solved unless you come back and say it isn't totally fixed yet.