Introduce install_or_cli_help and use it default bundle command

bundler/lib/bundler/cli.rb

@@ -120,20 +120,28 @@ def cli_help
       self.class.send(:class_options_help, shell)
     end
 
+    desc "install_or_cli_help", "Tries to run bundle install but prints a summary of bundler commands if there is no Gemfile", hide: true
+    def install_or_cli_help
+      invoke_other_command("install")
+    rescue GemfileNotFound => error
+      Bundler.ui.error error.message, wrap: true
+      invoke_other_command("cli_help")
+    end
+
     def self.default_command(meth = nil)
       return super if meth
 
-      default_cli_command = Bundler.settings[:default_cli_command]
-      return default_cli_command if default_cli_command
-
-      Bundler.ui.warn(<<~MSG)
-        In the next version of Bundler, running `bundle` without argument will no longer run `bundle install`.
-        Instead, the `help` command will be displayed.
-
-        If you'd like to keep the previous behaviour please run `bundle config set default_cli_command install --global`.
-      MSG
+      unless Bundler.settings[:default_cli_command]
+        Bundler.ui.info <<-MSG
+          In the feature version of Bundler, running `bundle` without argument will no longer run `bundle install`.
+          Instead, the `cli_help` command will be displayed. Please use `bundle install` explicitly for scripts like CI/CD.
+          If you wish to use feature behavior now with `bundle config set default_cli_command cli_help --global`
+          or you can continue to use the old behavior with `bundle config set default_cli_command install_or_cli_help --global`.
+          This message will be removed after a default_cli_command value is set.
+        MSG
+      end
 
-      "install"
+      Bundler.settings[:default_cli_command] || "install_or_cli_help"
     end
 
     class_option "no-color", type: :boolean, desc: "Disable colorization in output"
@@ -723,6 +731,19 @@ def current_command
       config[:current_command]
     end
 
+    def invoke_other_command(name)
+      _, _, config = @_initializer
+      original_command = config[:current_command]
+      command = self.class.all_commands[name]
+      config[:current_command] = command
+      send(name)
+    ensure
+      config[:current_command] = original_command
+    end
+
+    def current_command=(command)
+    end
+
     def print_command
       return unless Bundler.ui.debug?
       cmd = current_command

bundler/lib/bundler/vendor/thor/lib/thor.rb

@@ -625,7 +625,7 @@ def normalize_command_name(meth) #:nodoc:
     # alias name.
     def find_command_possibilities(meth)
       len = meth.to_s.length
-      possibilities = all_commands.merge(map).keys.select { |n| meth == n[0, len] }.sort
+      possibilities = all_commands.reject { |_k, c| c.hidden? }.merge(map).keys.select { |n| meth == n[0, len] }.sort
       unique_possibilities = possibilities.map { |k| map[k] || k }.uniq
 
       if possibilities.include?(meth)

bundler/spec/bundler/cli_spec.rb

@@ -87,16 +87,11 @@ def out_with_macos_man_workaround
   end
 
   context "with no arguments" do
-    it "installs and log a warning by default" do
+    it "tries to installs by default but print help on missing Gemfile" do
       bundle "", raise_on_error: false
-      expect(err).to include("running `bundle` without argument will no longer run `bundle install`.")
       expect(err).to include("Could not locate Gemfile")
-    end
+      expect(out).to include("In the feature version of Bundler")
 
-    it "prints a concise help message when default_cli_command set to cli_help" do
-      bundle "config set default_cli_command cli_help"
-      bundle ""
-      expect(err).to be_empty
       expect(out).to include("Bundler version #{Bundler::VERSION}").
         and include("\n\nBundler commands:\n\n").
         and include("\n\n  Primary commands:\n").
@@ -105,8 +100,9 @@ def out_with_macos_man_workaround
     end
 
     it "runs bundle install when default_cli_command set to install" do
-      bundle "config set default_cli_command install"
+      bundle "config set default_cli_command install_or_cli_help"
       bundle "", raise_on_error: false
+      expect(out).to_not include("In the feature version of Bundler")
       expect(err).to include("Could not locate Gemfile")
     end
   end

bundler/spec/other/cli_dispatch_spec.rb

@@ -15,6 +15,6 @@
 
   it "print a friendly error when ambiguous" do
     bundle "in", raise_on_error: false
-    expect(err).to eq("Ambiguous command in matches [info, init, inject, install]")
+    expect(err).to eq("Ambiguous command in matches [info, init, install]")
   end
 end

tool/automatiek/thor-v1.4.0.patch

@@ -1,3 +1,17 @@
+diff --git a/bundler/lib/bundler/vendor/thor/lib/thor.rb b/bundler/lib/bundler/vendor/thor/lib/thor.rb
+index bfd9f5c914..945bdbd551 100644
+--- a/bundler/lib/bundler/vendor/thor/lib/thor.rb
++++ b/bundler/lib/bundler/vendor/thor/lib/thor.rb
+@@ -625,7 +625,7 @@ def normalize_command_name(meth) #:nodoc:
+     # alias name.
+     def find_command_possibilities(meth)
+       len = meth.to_s.length
+-      possibilities = all_commands.merge(map).keys.select { |n| meth == n[0, len] }.sort
++      possibilities = all_commands.reject { |_k, c| c.hidden? }.merge(map).keys.select { |n| meth == n[0, len] }.sort
+       unique_possibilities = possibilities.map { |k| map[k] || k }.uniq
+
+       if possibilities.include?(meth)
+
 diff --git a/bundler/lib/bundler/vendor/thor/lib/thor/runner.rb b/bundler/lib/bundler/vendor/thor/lib/thor/runner.rb
 index 95f8b16e31..f0ce6df96c 100644
 --- a/bundler/lib/bundler/vendor/thor/lib/thor/runner.rb