Install further packages automatically

PC has the notion of "dependent" or additional packages.  These are
defined in a standard "Package Control.sublime-settings" file, hosted
by the package.  (I.e. similar to the "dependencies.json".)

Installing such a package did not install the additional packages in one
go, neither did it notify about the incomplete install.  In the end, a
restart is enough and required to trigger `install_missing_packages()`
to catch up and install everything.

We have two options here.  (1) to bail out `install_package` with
`return None` and a message to tell the user to restart Sublime, or (2)
to install the packages in a recursive style.

Here we choose (2).

We patch `run_install_tasks` to notify about its outcome to fail the
parent task if necessary.  This way necessary restarts bubble up.

Author: kaste

package_control/package_manager.py

@@ -40,6 +40,7 @@
     regular_file_exists,
     zip_file_exists,
 )
+from .package_tasks import PackageTaskRunner
 from .package_version import PackageVersion, version_sort
 from .providers import CHANNEL_PROVIDERS, REPOSITORY_PROVIDERS
 from .providers.channel_provider import UncachedChannelRepositoryError
@@ -1600,6 +1601,43 @@ def install_package(self, package_name, unattended=False):
                     fail_early=False
                 )
 
+            try:
+                extra_pc_settings_json = package_zip.read(common_folder + 'Package Control.sublime-settings')
+                extra_pc_settings = json.loads(extra_pc_settings_json.decode('utf-8'))
+            except (KeyError):
+                pass
+            except (ValueError):
+                console_write(
+                    '''
+                    Failed to parse the Package Control.sublime-settings for "%s"
+                    ''',
+                    package_name
+                )
+            else:
+                wanted_packages = set(extra_pc_settings.get('installed_packages') or [])
+                pc_settings = sublime.load_settings(pc_settings_filename())
+                in_process_packages = load_list_setting(pc_settings, 'in_process_packages')
+                additional_packages = wanted_packages - in_process_packages - self.installed_packages()
+                if additional_packages:
+                    task_runner = PackageTaskRunner(self)
+                    tasks = task_runner.create_package_tasks(
+                        actions=(self.INSTALL, self.OVERWRITE),
+                        include_packages=additional_packages
+                    )
+                    if tasks:
+                        outcome = task_runner.run_install_tasks(
+                            tasks, unattended=unattended, package_kind='additional'
+                        )
+                        if outcome is False:
+                            console_write(
+                                '''
+                                Failed to install %s -
+                                deferring until next start
+                                ''',
+                                package_name
+                            )
+                            return None
+
             if package_name != old_package_name:
                 self.rename_package(old_package_name, package_name)
 

package_control/package_tasks.py

@@ -362,6 +362,10 @@ def run_install_tasks(self, tasks, progress=None, unattended=False, package_kind
         :param package_kind:
             A unicode string with an additional package attribute.
             (e.g.: `missing`, ...)
+
+        :return:
+            ``True``, if install was completed.
+            ``False``, if a restart is required.
         """
 
         if package_kind:
@@ -384,6 +388,7 @@ def run_install_tasks(self, tasks, progress=None, unattended=False, package_kind
 
         num_success = 0
 
+        success = True
         try:
             for task in tasks:
                 if progress:
@@ -393,6 +398,7 @@ def run_install_tasks(self, tasks, progress=None, unattended=False, package_kind
                     num_success += 1
                 # do not re-enable package if operation is deferred to next start
                 elif result is None:
+                    success = False
                     package_names.remove(task.package_name)
 
             if num_packages == 1:
@@ -412,6 +418,8 @@ def run_install_tasks(self, tasks, progress=None, unattended=False, package_kind
             time.sleep(0.7)
             self.reenable_packages({self.INSTALL: package_names})
 
+        return success
+
     def run_upgrade_tasks(self, tasks, progress=None, unattended=False):
         """
         Execute specified package update tasks