From 467d90a6dc14c802c37081643c70cc161b05e81f Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Wed, 23 May 2018 05:51:53 +0200
Subject: [PATCH] Don't fallback to tempdir when required directories exist.

When home directory is not writable, but the required .bundle is,
we should use it instead of falling back to use tempdirs.

This creates a workaround for more restrictive setups using Omnibus
Docker or any hardened setup, to overcome the annoyances introduced by #4951.
---
 lib/bundler.rb               |  3 ++-
 spec/bundler/bundler_spec.rb | 51 ++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/lib/bundler.rb b/lib/bundler.rb
index 9944ebd0513..e4f5bce75d0 100644
--- a/lib/bundler.rb
+++ b/lib/bundler.rb
@@ -159,12 +159,13 @@ def ruby_scope
     def user_home
       @user_home ||= begin
         home = Bundler.rubygems.user_home
+        dotbundle = home ? File.join(home, '.bundle') : nil
 
         warning = if home.nil?
           "Your home directory is not set."
         elsif !File.directory?(home)
           "`#{home}` is not a directory."
-        elsif !File.writable?(home)
+        elsif !File.writable?(home) && (!File.directory?(dotbundle) || !File.writable?(dotbundle))
           "`#{home}` is not writable."
         end
 
diff --git a/spec/bundler/bundler_spec.rb b/spec/bundler/bundler_spec.rb
index 131146119e1..c483701d6e8 100644
--- a/spec/bundler/bundler_spec.rb
+++ b/spec/bundler/bundler_spec.rb
@@ -199,6 +199,57 @@
         allow(File).to receive(:writable?).with(path).and_return true
         expect(Bundler.user_home).to eq(Pathname(path))
       end
+
+      context "is not a directory" do
+        it "should issue a warning and return a temporary user home" do
+          path = "/home/oggy"
+          allow(Bundler.rubygems).to receive(:user_home).and_return(path)
+          allow(File).to receive(:directory?).with(path).and_return false
+          allow(Etc).to receive(:getlogin).and_return("USER")
+          allow(Dir).to receive(:tmpdir).and_return("/TMP")
+          allow(FileTest).to receive(:exist?).with("/TMP/bundler/home").and_return(true)
+          expect(FileUtils).to receive(:mkpath).with("/TMP/bundler/home/USER")
+          message = <<EOF
+`/home/oggy` is not a directory.
+Bundler will use `/TMP/bundler/home/USER' as your home directory temporarily.
+EOF
+          expect(Bundler.ui).to receive(:warn).with(message)
+          expect(Bundler.user_home).to eq(Pathname("/TMP/bundler/home/USER"))
+        end
+      end
+
+      context "is not writable" do
+        let(:path) { "/home/oggy" }
+        let(:dotbundle) { "/home/oggy/.bundle" }
+
+        it "should issue a warning and return a temporary user home" do
+          allow(Bundler.rubygems).to receive(:user_home).and_return(path)
+          allow(File).to receive(:directory?).with(path).and_return true
+          allow(File).to receive(:writable?).with(path).and_return false
+          allow(File).to receive(:directory?).with(dotbundle).and_return false
+          allow(Etc).to receive(:getlogin).and_return("USER")
+          allow(Dir).to receive(:tmpdir).and_return("/TMP")
+          allow(FileTest).to receive(:exist?).with("/TMP/bundler/home").and_return(true)
+          expect(FileUtils).to receive(:mkpath).with("/TMP/bundler/home/USER")
+          message = <<EOF
+`/home/oggy` is not writable.
+Bundler will use `/TMP/bundler/home/USER' as your home directory temporarily.
+EOF
+          expect(Bundler.ui).to receive(:warn).with(message)
+          expect(Bundler.user_home).to eq(Pathname("/TMP/bundler/home/USER"))
+        end
+
+        context ".bundle exists and have correct permissions" do
+          it "should return the user home" do
+            allow(Bundler.rubygems).to receive(:user_home).and_return(path)
+            allow(File).to receive(:directory?).with(path).and_return true
+            allow(File).to receive(:writable?).with(path).and_return false
+            allow(File).to receive(:directory?).with(dotbundle).and_return true
+            allow(File).to receive(:writable?).with(dotbundle).and_return true
+            expect(Bundler.user_home).to eq(Pathname(path))
+          end
+        end
+      end
     end
 
     context "home directory is not set" do