Fix PKG installer environment

This commit solves an issue where the environment handed to
`/usr/sbin/installer` is not the same as the environment used by the
graphical PKG installer.

This is evident in some post-install scripts, e. g. the
`component-10.pkg/Scripts/postinstall` script in the `dymo-label`
cask. The code says:

```
USER_ID=`id -u ${USER}`

launchctl bootstrap gui/$USER_ID /Library/LaunchAgents/com.dymo.dls.webservice.plist
```

The graphical installer will export e. g. `USER=alice`, and
everything works as intended.

However, `brew cask install` does not override `sudo`’s default,
which is `USER=ROOT`. This violates the assumptions in the script.

This commit fixes the issue by configuring `sudo` to override the
following environment variables with the proper user name:

- `LOGNAME`
- `USER`
- `USERNAME`

Library/Homebrew/cask/lib/hbc/artifact/pkg.rb

@@ -50,7 +50,13 @@ module Hbc
         end
         with_choices_file do |choices_path|
           args << "-applyChoiceChangesXML" << choices_path if choices_path
-          command.run!("/usr/sbin/installer", sudo: true, args: args, print_stdout: true)
+          logged_in_user = Utils.current_user
+          env = {
+            "LOGNAME" => logged_in_user,
+            "USER" => logged_in_user,
+            "USERNAME" => logged_in_user,
+          }
+          command.run!("/usr/sbin/installer", sudo: true, args: args, print_stdout: true, env: env)
         end
       end
 

Library/Homebrew/cask/lib/hbc/system_command.rb

@@ -37,7 +37,7 @@ module Hbc
       result
     end
 
-    def initialize(executable, args: [], sudo: false, input: [], print_stdout: false, print_stderr: true, must_succeed: false, path: ENV["PATH"], **options)
+    def initialize(executable, args: [], sudo: false, input: [], print_stdout: false, print_stderr: true, must_succeed: false, env: {}, **options)
       @executable = executable
       @args = args
       @sudo = sudo
@@ -47,7 +47,11 @@ module Hbc
       @must_succeed = must_succeed
       options.extend(HashValidator).assert_valid_keys(:chdir)
       @options = options
-      @path = path
+      @env = { "PATH" => ENV["PATH"] }.merge(env)
+
+      @env.keys.grep_v(/^[\w&&\D]\w*$/) do |name|
+        raise ArgumentError, "Invalid variable name: '#{name}'"
+      end
     end
 
     def command
@@ -56,14 +60,22 @@ module Hbc
 
     private
 
-    attr_reader :executable, :args, :input, :options, :processed_output, :processed_status, :path
+    attr_reader :executable, :args, :input, :options, :processed_output, :processed_status, :env
 
     attr_predicate :sudo?, :print_stdout?, :print_stderr?, :must_succeed?
 
     def sudo_prefix
       return [] unless sudo?
       askpass_flags = ENV.key?("SUDO_ASKPASS") ? ["-A"] : []
-      ["/usr/bin/sudo", *askpass_flags, "-E", "--"]
+      prefix = ["/usr/bin/sudo", *askpass_flags, "-E"]
+
+      env.each do |name, value|
+        sanitized_name = Shellwords.escape(name)
+        sanitized_value = Shellwords.escape(value)
+        prefix << "#{sanitized_name}=#{sanitized_value}"
+      end
+
+      prefix << "--"
     end
 
     def assert_success
@@ -85,7 +97,7 @@ module Hbc
       executable, *args = expanded_command
 
       raw_stdin, raw_stdout, raw_stderr, raw_wait_thr =
-        Open3.popen3({ "PATH" => path }, [executable, executable], *args, **options)
+        Open3.popen3(env, [executable, executable], *args, **options)
 
       write_input_to(raw_stdin)
       raw_stdin.close_write

Library/Homebrew/test/cask/artifact/pkg_spec.rb

@@ -15,6 +15,11 @@ describe Hbc::Artifact::Pkg, :cask do
         args: ["-pkg", cask.staged_path.join("MyFancyPkg", "Fancy.pkg"), "-target", "/"],
         sudo: true,
         print_stdout: true,
+        env: {
+          "LOGNAME" => ENV["USER"],
+          "USER" => ENV["USER"],
+          "USERNAME" => ENV["USER"],
+        },
       )
 
       pkg.install_phase(command: fake_system_command)
@@ -55,6 +60,11 @@ describe Hbc::Artifact::Pkg, :cask do
         args: ["-pkg", cask.staged_path.join("MyFancyPkg", "Fancy.pkg"), "-target", "/", "-applyChoiceChangesXML", cask.staged_path.join("/tmp/choices.xml")],
         sudo: true,
         print_stdout: true,
+        env: {
+          "LOGNAME" => ENV["USER"],
+          "USER" => ENV["USER"],
+          "USERNAME" => ENV["USER"],
+        },
       )
 
       pkg.install_phase(command: fake_system_command)

Library/Homebrew/test/cask/system_command_spec.rb

 describe Hbc::SystemCommand, :cask do
+  describe "#initialize" do
+    let(:env_args) { ["bash", "-c", 'printf "%s" "${A?}" "${B?}" "${C?}"'] }
+
+    describe "given some environment variables" do
+      subject {
+        described_class.new(
+          "env",
+          args: env_args,
+          env: { "A" => "1", "B" => "2", "C" => "3" },
+          must_succeed: true,
+        )
+      }
+
+      its("run!.stdout") { is_expected.to eq("123") }
+
+      describe "the resulting command line" do
+        it "does not include the given variables" do
+          expect(Open3)
+            .to receive(:popen3)
+            .with(a_hash_including("PATH"), ["env"] * 2, *env_args, {})
+            .and_call_original
+
+          subject.run!
+        end
+      end
+    end
+
+    describe "given some environment variables and sudo: true" do
+      subject {
+        described_class.new(
+          "env",
+          args: env_args,
+          env: { "A" => "1", "B" => "2", "C" => "3" },
+          must_succeed: true,
+          sudo: true,
+        )
+      }
+
+      describe "the resulting command line" do
+        it "includes the given variables explicitly" do
+          expect(Open3)
+            .to receive(:popen3)
+            .with(an_instance_of(Hash), ["/usr/bin/sudo"] * 2,
+                "-E", a_string_starting_with("PATH="),
+                "A=1", "B=2", "C=3", "--", "env", *env_args, {})
+            .and_wrap_original do |original_popen3, *_, &block|
+              original_popen3.call("/usr/bin/true", &block)
+            end
+
+          subject.run!
+        end
+      end
+    end
+  end
+
   describe "when the exit code is 0" do
     describe "its result" do
       subject { described_class.run("/usr/bin/true") }
@@ -134,4 +189,11 @@ describe Hbc::SystemCommand, :cask do
       }.to be_a_success
     end
   end
+
+  describe "given an invalid variable name" do
+    it "raises an ArgumentError" do
+      expect { described_class.run("true", env: { "1ABC" => true }) }
+        .to raise_error(ArgumentError, /variable name/)
+    end
+  end
 end

Library/Homebrew/test/support/helper/cask/fake_system_command.rb

 def sudo(*args)
-  %w[/usr/bin/sudo -E --] + args.flatten
+  ["/usr/bin/sudo", "-E", "PATH=#{ENV["PATH"]}", "--"] + args.flatten
 end
 
 module Hbc

Library/Homebrew/test/support/helper/spec/shared_examples/hbc_staged.rb

@@ -80,7 +80,7 @@ shared_examples Hbc::Staged do
     allow(staged).to receive(:Pathname).and_return(fake_pathname)
 
     Hbc::FakeSystemCommand.expects_command(
-      ["/usr/bin/sudo", "-E", "--", "/usr/sbin/chown", "-R", "--", "fake_user:staff", fake_pathname],
+      ["/usr/bin/sudo", "-E", "PATH=#{ENV["PATH"]}", "--", "/usr/sbin/chown", "-R", "--", "fake_user:staff", fake_pathname],
     )
 
     staged.set_ownership(fake_pathname.to_s)
@@ -93,7 +93,7 @@ shared_examples Hbc::Staged do
     allow(staged).to receive(:Pathname).and_return(fake_pathname)
 
     Hbc::FakeSystemCommand.expects_command(
-      ["/usr/bin/sudo", "-E", "--", "/usr/sbin/chown", "-R", "--", "fake_user:staff", fake_pathname, fake_pathname],
+      ["/usr/bin/sudo", "-E", "PATH=#{ENV["PATH"]}", "--", "/usr/sbin/chown", "-R", "--", "fake_user:staff", fake_pathname, fake_pathname],
     )
 
     staged.set_ownership([fake_pathname.to_s, fake_pathname.to_s])
@@ -105,7 +105,7 @@ shared_examples Hbc::Staged do
     allow(staged).to receive(:Pathname).and_return(fake_pathname)
 
     Hbc::FakeSystemCommand.expects_command(
-      ["/usr/bin/sudo", "-E", "--", "/usr/sbin/chown", "-R", "--", "other_user:other_group", fake_pathname],
+      ["/usr/bin/sudo", "-E", "PATH=#{ENV["PATH"]}", "--", "/usr/sbin/chown", "-R", "--", "other_user:other_group", fake_pathname],
     )
 
     staged.set_ownership(fake_pathname.to_s, user: "other_user", group: "other_group")