Merge Bundler 2.1.0.pre.3

  Features:
    - Add caller information to some deprecation messages to make them easier to fix [#7361](https://github.com/bundler/bundler/pull/7361)
    - Reconcile `bundle cache` vs `bundle package` everywhere. Now in docs, CLI help and everywhere else `bundle cache` is the preferred version and `bundle package` remains as an alias [#7389](https://github.com/bundler/bundler/pull/7389)
    - Display some basic `bundler` documentation together with ruby's RDoc based documentation [#7394](https://github.com/bundler/bundler/pull/7394)

  Bugfixes:
    - Fix typos deprecation message and upgrading docs [#7374](https://github.com/bundler/bundler/pull/7374)
    - Deprecation warnings about `taint` usage on ruby 2.7 [#7385](https://github.com/bundler/bundler/pull/7385)
    - Fix `--help` flag not correctly delegating to `man` when used with command aliases [#7388](https://github.com/bundler/bundler/pull/7388)
    - `bundle add` should cache newly added gems if an application cache exists [#7393](https://github.com/bundler/bundler/pull/7393)
    - Stop using an insecure folder as a "fallback home" when user home is not defined [#7416](https://github.com/bundler/bundler/pull/7416)
    - Fix `bundler/inline` warning about `Bundler.root` redefinition [#7417](https://github.com/bundler/bundler/pull/7417)

3 files changed, 49 insertions, 7 deletions

diff --git a/lib/bundler/cli/add.rb b/lib/bundler/cli/add.rb
index 7c6235f17c..07b951f1ef 100644
--- a/lib/bundler/cli/add.rb
+++ b/lib/bundler/cli/add.rb
@@ -21,6 +21,7 @@ module Bundler
 
     def perform_bundle_install
       Installer.install(Bundler.root, Bundler.definition)
+      Bundler.load.cache if Bundler.app_cache.exist?
     end
 
     def inject_dependencies
diff --git a/lib/bundler/cli/cache.rb b/lib/bundler/cli/cache.rb
new file mode 100644
index 0000000000..5e8420990f
--- /dev/null
+++ b/lib/bundler/cli/cache.rb
@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+module Bundler
+  class CLI::Cache
+    attr_reader :options
+
+    def initialize(options)
+      @options = options
+    end
+
+    def run
+      Bundler.ui.level = "error" if options[:quiet]
+      Bundler.settings.set_command_option_if_given :path, options[:path]
+      Bundler.settings.set_command_option_if_given :cache_path, options["cache-path"]
+
+      setup_cache_all
+      install
+
+      # TODO: move cache contents here now that all bundles are locked
+      custom_path = Bundler.settings[:path] if options[:path]
+
+      Bundler.settings.temporary(:cache_all_platforms => options["all-platforms"]) do
+        Bundler.load.cache(custom_path)
+      end
+    end
+
+  private
+
+    def install
+      require_relative "install"
+      options = self.options.dup
+      options["local"] = false if Bundler.settings[:cache_all_platforms]
+      Bundler::CLI::Install.new(options).run
+    end
+
+    def setup_cache_all
+      all = options.fetch(:all, Bundler.feature_flag.cache_all? || nil)
+
+      Bundler.settings.set_command_option_if_given :cache_all, all
+
+      if Bundler.definition.has_local_dependencies? && !Bundler.feature_flag.cache_all?
+        Bundler.ui.warn "Your Gemfile contains path and git dependencies. If you want "    \
+          "to cache them as well, please pass the --all flag. This will be the default " \
+          "on Bundler 3.0."
+      end
+    end
+  end
+end
diff --git a/lib/bundler/cli/exec.rb b/lib/bundler/cli/exec.rb
index 0b0e991ea5..0a1edbdbbd 100644
--- a/lib/bundler/cli/exec.rb
+++ b/lib/bundler/cli/exec.rb
@@ -43,15 +43,11 @@ module Bundler
     end
 
     def kernel_exec(*args)
-      ui = Bundler.ui
-      Bundler.ui = nil
       Kernel.exec(*args)
     rescue Errno::EACCES, Errno::ENOEXEC
-      Bundler.ui = ui
       Bundler.ui.error "bundler: not executable: #{cmd}"
       exit 126
     rescue Errno::ENOENT
-      Bundler.ui = ui
       Bundler.ui.error "bundler: command not found: #{cmd}"
       Bundler.ui.warn "Install missing gem executables with `bundle install`"
       exit 127
@@ -62,15 +58,12 @@ module Bundler
       ARGV.replace(args)
       $0 = file
       Process.setproctitle(process_title(file, args)) if Process.respond_to?(:setproctitle)
-      ui = Bundler.ui
-      Bundler.ui = nil
       require_relative "../setup"
       TRAPPED_SIGNALS.each {|s| trap(s, "DEFAULT") }
       Kernel.load(file)
     rescue SystemExit, SignalException
       raise
     rescue Exception => e # rubocop:disable Lint/RescueException
-      Bundler.ui = ui
       Bundler.ui.error "bundler: failed to load command: #{cmd} (#{file})"
       backtrace = e.backtrace ? e.backtrace.take_while {|bt| !bt.start_with?(__FILE__) } : []
       abort "#{e.class}: #{e.message}\n  #{backtrace.join("\n  ")}"