From ea3498f9c9cadeaed7e6a155bc3c4585a17133c9 Mon Sep 17 00:00:00 2001
From: "Alan D. Salewski" <salewski@att.net>
Date: Thu, 9 Apr 2020 07:11:00 -0400
Subject: [PATCH] fixes #46 (unit tests): missing $HOME relevant only w/o
 passwd->pw_dir

When Ruby's `Dir` class obtains the user's home directory from the password
database via `getpwname(3)`, the `${HOME}` environment variable is not
consulted. In such a case, `Dir.home` will return the value from the `passwd`
struct's `pw_dir` member, and the last resort fallback use of `Dir.pwd` (by
`Netrc.home_path`) is not triggered.

The `test_missing_environment()` unit test was failing on my machine (Debian
GNU/Linux, amd64, libc6 2.28, Ruby 2.5) because it expected that by removing
the `${HOME}` environment variable the `Netrc` class would have constructed
its `default_path` from the `Dir.pwd` fallback. That was not the behavior,
though, when Ruby's `Dir.home` was able to return a valid, readable directory
from the password database (and the build process was not in that directory
when running the unit tests).

This change tweaks the unit test to conditionally expect the use of `Dir.home`
rather than `Dir.pwd`.
---
 test/test_netrc.rb | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/test/test_netrc.rb b/test/test_netrc.rb
index 73c5c25..dab0a38 100644
--- a/test/test_netrc.rb
+++ b/test/test_netrc.rb
@@ -200,7 +200,15 @@ def test_encrypted_roundtrip
   def test_missing_environment
     nil_home = nil
     ENV["HOME"], nil_home = nil_home, ENV["HOME"]
-    assert_equal File.join(Dir.pwd, '.netrc'), Netrc.default_path
+
+    # If user's home directory can be obtained via getpwnam(3) AND is
+    # readable, then the $HOME environment variable is not considered for
+    # building the Netrc default_path, and no fallback directory is
+    # referenced.
+    dflt_dir = Dir.respond_to?(:home) && File.readable?(Dir.home) \
+             ? Dir.home : Dir.pwd
+
+    assert_equal File.join(dflt_dir, '.netrc'), Netrc.default_path
   ensure
     ENV["HOME"], nil_home = nil_home, ENV["HOME"]
   end