From 1031879b87c137f2197ecf8c5af0d10da9d3a354 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Rodr=C3=ADguez?= <deivid.rodriguez@riseup.net>
Date: Sat, 30 Oct 2021 09:48:57 +0200
Subject: [PATCH] Leave ":" after MANPATH when not set

So that system man pages still work after a gem with man pages overrides
it.
---
 bundler/lib/bundler/runtime.rb     |  2 +-
 bundler/spec/runtime/setup_spec.rb | 71 +++++++++++++++++++++---------
 bundler/spec/support/filters.rb    |  1 +
 3 files changed, 51 insertions(+), 23 deletions(-)

diff --git a/bundler/lib/bundler/runtime.rb b/bundler/lib/bundler/runtime.rb
index 31e71388a685..c7276b0e2511 100644
--- a/bundler/lib/bundler/runtime.rb
+++ b/bundler/lib/bundler/runtime.rb
@@ -265,7 +265,7 @@ def setup_manpath
 
       return if manuals.empty?
       Bundler::SharedHelpers.set_env "MANPATH", manuals.concat(
-        ENV["MANPATH"].to_s.split(File::PATH_SEPARATOR)
+        ENV["MANPATH"] ? ENV["MANPATH"].to_s.split(File::PATH_SEPARATOR) : [""]
       ).uniq.join(File::PATH_SEPARATOR)
     end
 
diff --git a/bundler/spec/runtime/setup_spec.rb b/bundler/spec/runtime/setup_spec.rb
index 3cf373fe1ca3..00fed5201189 100644
--- a/bundler/spec/runtime/setup_spec.rb
+++ b/bundler/spec/runtime/setup_spec.rb
@@ -745,41 +745,68 @@ def clean_load_path(lp)
     expect(err).to be_empty
   end
 
-  describe "$MANPATH" do
-    before do
+  context "when the user has `MANPATH` set", :man do
+    before { ENV["MANPATH"] = "/foo#{File::PATH_SEPARATOR}" }
+
+    it "adds the gem's man dir to the MANPATH" do
       build_repo4 do
         build_gem "with_man" do |s|
           s.write("man/man1/page.1", "MANPAGE")
         end
       end
+
+      install_gemfile <<-G
+        source "#{file_uri_for(gem_repo4)}"
+        gem "with_man"
+      G
+
+      run "puts ENV['MANPATH']"
+      expect(out).to eq("#{default_bundle_path("gems/with_man-1.0/man")}#{File::PATH_SEPARATOR}/foo")
     end
+  end
 
-    context "when the user has one set" do
-      before { ENV["MANPATH"] = "/foo#{File::PATH_SEPARATOR}" }
+  context "when the user does not have `MANPATH` set", :man do
+    before { ENV.delete("MANPATH") }
 
-      it "adds the gem's man dir to the MANPATH" do
-        install_gemfile <<-G
-          source "#{file_uri_for(gem_repo4)}"
-          gem "with_man"
-        G
+    it "adds the gem's man dir to the MANPATH, leaving : in the end so that system man pages still work" do
+      build_repo4 do
+        build_gem "with_man" do |s|
+          s.write("man/man1/page.1", "MANPAGE")
+        end
 
-        run "puts ENV['MANPATH']"
-        expect(out).to eq("#{default_bundle_path("gems/with_man-1.0/man")}#{File::PATH_SEPARATOR}/foo")
+        build_gem "with_man_overriding_system_man" do |s|
+          s.write("man/man1/ls.1", "LS MANPAGE")
+        end
       end
-    end
 
-    context "when the user does not have one set" do
-      before { ENV.delete("MANPATH") }
+      install_gemfile <<-G
+        source "#{file_uri_for(gem_repo4)}"
+        gem "with_man"
+      G
 
-      it "adds the gem's man dir to the MANPATH" do
-        install_gemfile <<-G
-          source "#{file_uri_for(gem_repo4)}"
-          gem "with_man"
-        G
+      run <<~RUBY
+        puts ENV['MANPATH']
+        require "open3"
+        puts Open3.capture2e("man", "ls")[1].success?
+      RUBY
 
-        run "puts ENV['MANPATH']"
-        expect(out).to eq(default_bundle_path("gems/with_man-1.0/man").to_s)
-      end
+      expect(out).to eq("#{default_bundle_path("gems/with_man-1.0/man")}#{File::PATH_SEPARATOR}\ntrue")
+
+      install_gemfile <<-G
+        source "#{file_uri_for(gem_repo4)}"
+        gem "with_man_overriding_system_man"
+      G
+
+      run <<~RUBY
+        puts ENV['MANPATH']
+        require "open3"
+        puts Open3.capture2e("man", "ls")[0]
+      RUBY
+
+      lines = out.split("\n")
+
+      expect(lines).to include("#{default_bundle_path("gems/with_man_overriding_system_man-1.0/man")}#{File::PATH_SEPARATOR}")
+      expect(lines).to include("LS MANPAGE")
     end
   end
 
diff --git a/bundler/spec/support/filters.rb b/bundler/spec/support/filters.rb
index 0c1f27e47058..3b91897a2e13 100644
--- a/bundler/spec/support/filters.rb
+++ b/bundler/spec/support/filters.rb
@@ -34,6 +34,7 @@ def inspect
   config.filter_run_excluding :readline => Gem.win_platform?
   config.filter_run_excluding :jruby => RUBY_ENGINE != "jruby"
   config.filter_run_excluding :truffleruby => RUBY_ENGINE != "truffleruby"
+  config.filter_run_excluding :man => Gem.win_platform?
 
   config.filter_run_when_matching :focus unless ENV["CI"]
 end