[PATCH] Allow help/--help/-h to be run outside of a TopGit repo

The user ought to be able to call `tg help` from anywhere in the filesystem,
not just Git repositories, so the help parsing has to happen before the calls
to git git binary.

Debian bug: #501982

Signed-off-by: martin f. krafft <redacted>

---
 tg.sh |   28 +++++++++++++++++++++++++---
 1 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/tg.sh b/tg.sh
index 4dcc15e..258f8ce 100644
--- a/tg.sh
+++ b/tg.sh

@@ -235,12 +235,37 @@ do_help()
 	fi
 }
 
+# Check whether we are supposed to output the help message
+should_do_help()
+{
+	# we are being sourced for utility functions, never run help
+	[ -z "$tg__include" ] || return 1
+
+	local prev
+	while [ -n "$1" ]; do
+		case "$1" in
+		help|--help|-h)
+			shift
+			echo "${1:-$prev}"
+			return 0
+		esac
+		prev="$1"
+		shift
+	done
+
+	# run help when there was no previous topic, meaning that there where
+	# no arguments at all
+	test -z "$prev"
+}
 
 ## Startup
 
 [ -d "@cmddir@" ] ||
 	die "No command directory: '@cmddir@'"
 
+# check if we should run help and get the topic while we're at it
+help_topic="$(should_do_help "$@")" && { do_help "$help_topic"; exit 0; }
+
 ## Initial setup
 
 set -e

@@ -270,9 +295,6 @@ cmd="$1"
 shift
 
 case "$cmd" in
-help|--help|-h)
-	do_help "$1"
-	exit 0;;
 --hooks-path)
 	# Internal command
 	echo "@hooksdir@";;

-- 
tg: (f17218e..) fixes/independent-help (depends on: upstream)

On Thu, Nov 20, 2008 at 12:46:34PM +0100, martin f. krafft wrote:

Why is this so complicated? Can't you just do_help from
should_do_help()? The overall semantics seems strange anyway, though -
it seems that 'tg mail --help -r' will try to show help for '-r' instead
of 'mail'.

-- 
				Petr "Pasky" Baudis
People who take cold baths never have rheumatism, but they have
cold baths.

also sprach Petr Baudis [off-list ref] [2008.11.20.1527 +0100]:

Why is this so complicated? Can't you just do_help from
should_do_help()?

Yes, I could, but that would be in conflict with my understanding of
the Law of Demeter.

The overall semantics seems strange anyway, though - it seems that
'tg mail --help -r' will try to show help for '-r' instead of
'mail'.

True, but then we are parsing command lines. Would you be opposed to
a getopt (POSIX) approach to normalising/parsing the command line?

Cheers,

-- 
 .''`.   martin f. krafft [off-list ref]
: :'  :  proud Debian developer, author, administrator, and user
`. `'`   http://people.debian.org/~madduck - http://debiansystem.info
  `-  Debian - when you have better things to do than fixing systems
 
this space intentionally left occupied.

On Thu, Nov 20, 2008 at 03:55:11PM +0100, martin f krafft wrote:

also sprach Petr Baudis [off-list ref] [2008.11.20.1527 +0100]:

quoted

Why is this so complicated? Can't you just do_help from
should_do_help()?

Yes, I could, but that would be in conflict with my understanding of
the Law of Demeter.

What is that?

quoted

The overall semantics seems strange anyway, though - it seems that
'tg mail --help -r' will try to show help for '-r' instead of
'mail'.

True, but then we are parsing command lines. Would you be opposed to
a getopt (POSIX) approach to normalising/parsing the command line?

No. :-)

				Petr "Pasky" Baudis

also sprach Petr Baudis [off-list ref] [2008.11.20.1608 +0100]:

What is that?

http://en.wikipedia.org/wiki/Law_of_Demeter

In the context of our discussion, it basically means that if
should_do_help calls do_help, then we cannot test should_do_help
independently (without mocking out do_help, which is plain ugly).
Not that we have a testing infrastructure (yet) anyway, but...

quoted

True, but then we are parsing command lines. Would you be opposed to
a getopt (POSIX) approach to normalising/parsing the command line?

No. :-)

Good. I will see what I can do about this. In the mean time, I will
just leave things as they are.

-- 
 .''`.   martin f. krafft [off-list ref]
: :'  :  proud Debian developer, author, administrator, and user
`. `'`   http://people.debian.org/~madduck - http://debiansystem.info
  `-  Debian - when you have better things to do than fixing systems
 
windoze nt crashed.
i am the blue screen of death.
no one hears your screams.