repo: refactor help output handling

Currently we have the behavior:
* `repo`: Equivalent to `repo help` -- only shows common subcommands
  (with short description), and then exits 0.
* `repo --help`: Shows repo's core options, lists all commands (no
  specific info), and then exits 0.

The first case is not behaving well:
* If you run `repo` without a specific subcommand, that's an error,
  so we should be exiting 1 instead.
* Showing only subcommands and no actual option summary makes it seem
  like repo itself doesn't take any options.  This confuses users.

Let's rework things a bit.  Now we have the behavior:
* `repo`: Shows repo's core options, lists all commands (no specific
  info), and then exits 1.
* `repo --help`: Shows repo's core options, shows common subcommands
  (with short description), and then exits 0.
* `repo --help-all`: Shows repo's core options, shows all subcommands
  (with short description), and then exits 0.

Basically we swap the behavior of `repo` and `repo --help`, and fix
the exit status when the subcommand is missing.

The addition of --help-all is mostly for the man pages.  We were
relying on `repo help --all` to generate the repo(1) man page, but
that too omitted the core repo options.  Now the man page includes
all the core repo options and provides a summary of all commands.

Change-Id: I1f99b99d5b8af2591f96a078d0647a3d76d6b0fc
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/312908
Reviewed-by: Xin Li <delphij@google.com>
Tested-by: Mike Frysinger <vapier@google.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/subcmds/help.py b/subcmds/help.py
index f302e75c..1a60ef45 100644
--- a/subcmds/help.py
+++ b/subcmds/help.py
@@ -50,14 +50,21 @@ Displays detailed usage information about a command.
 
   def _PrintAllCommands(self):
     print('usage: repo COMMAND [ARGS]')
+    self.PrintAllCommandsBody()
+
+  def PrintAllCommandsBody(self):
     print('The complete list of recognized repo commands are:')
     commandNames = list(sorted(all_commands))
     self._PrintCommands(commandNames)
     print("See 'repo help <command>' for more information on a "
           'specific command.')
+    print('Bug reports:', Wrapper().BUG_URL)
 
   def _PrintCommonCommands(self):
     print('usage: repo COMMAND [ARGS]')
+    self.PrintCommonCommandsBody()
+
+  def PrintCommonCommandsBody(self):
     print('The most commonly used repo commands are:')
 
     def gitc_supported(cmd):