gitc: Improve help visibility

This improves the visiblity of gitc-init if we can get the gitc config,
and hides it otherwise.

Change-Id: I82830b0b07c311e8c74397ba79eb4c361f8b6fb5
diff --git a/repo b/repo
index 01c1cb0..b7d8024 100755
--- a/repo
+++ b/repo
@@ -214,6 +214,7 @@
                  help='Always prompt for name/e-mail')
 
 def _GitcInitOptions(init_optparse):
+  init_optparse.set_usage("repo gitc-init -u url -c client [options]")
   g = init_optparse.add_option_group('GITC options')
   g.add_option('-f', '--manifest-file',
                dest='manifest_file',
@@ -272,9 +273,12 @@
     if gitc_init:
       gitc_manifest_dir = get_gitc_manifest_dir()
       if not gitc_manifest_dir:
-        _print('error: GITC filesystem is not running. Exiting...',
+        _print('fatal: GITC filesystem is not available. Exiting...',
                file=sys.stderr)
         sys.exit(1)
+      if not opt.gitc_client:
+        _print('fatal: GITC client (-c) is required.', file=sys.stderr)
+        sys.exit(1)
       client_dir = os.path.join(gitc_manifest_dir, opt.gitc_client)
       if not os.path.exists(client_dir):
         os.makedirs(client_dir)
@@ -681,6 +685,10 @@
 
 
 def _Usage():
+  gitc_usage = ""
+  if get_gitc_manifest_dir():
+    gitc_usage = "  gitc-init Initialize a GITC Client.\n"
+
   _print(
 """usage: repo COMMAND [ARGS]
 
@@ -689,7 +697,8 @@
 The most commonly used repo commands are:
 
   init      Install repo in the current working directory
-  help      Display detailed help on a command
+""" + gitc_usage +
+"""  help      Display detailed help on a command
 
 For access to the full online help, install repo ("repo init").
 """, file=sys.stderr)
@@ -701,6 +710,10 @@
     if args[0] == 'init':
       init_optparse.print_help()
       sys.exit(0)
+    elif args[0] == 'gitc-init':
+      _GitcInitOptions(init_optparse)
+      init_optparse.print_help()
+      sys.exit(0)
     else:
       _print("error: '%s' is not a bootstrap command.\n"
              '        For access to online help, install repo ("repo init").'