[PATCH] parse-options.c: fix documentation syntax of optional arguments

[Michele Ballabio <barra_cuda@katamail.com>]

When an argument for an option is optional, short options don't need a
space between the option and the argument, and long options need a "=".
Otherwise, arguments are misinterpreted.

Signed-off-by: Michele Ballabio <barra_cuda@katamail.com>
---

On Sunday 22 June 2008, Stephan Beyer wrote:
> > > +`OPT__ABBREV(&int_var)`::
> > > +       Add `\--abbrev [<n>]`.
> > 
> > better:
> > +       Add `\--abbrev[=<n>]`.
> > 
> > since the <n> is optional.
> 
> That's right and I also expected that print_usage_with_options() would
> do so, since the other variant is ambiguous, BUT:
> 
> $ ./test-parse-options -h 2>&1 | grep abbrev
>     --abbrev [<n>]        use <n> digits to display SHA-1s
> 
> And I didn't want to change parse-options.c ;-)

Here it is.

 parse-options.c               |   15 ++++++++++++---
 t/t1502-rev-parse-parseopt.sh |    2 +-
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/parse-options.c b/parse-options.c
index acf3fe3..f8d52e2 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -344,7 +344,10 @@ void usage_with_options_internal(const char * const *usagestr,
 			break;
 		case OPTION_INTEGER:
 			if (opts->flags & PARSE_OPT_OPTARG)
-				pos += fprintf(stderr, "[<n>]");
+				if (opts->long_name)
+					pos += fprintf(stderr, "[=<n>]");
+				else
+					pos += fprintf(stderr, "[<n>]");
 			else
 				pos += fprintf(stderr, " <n>");
 			break;
@@ -355,12 +358,18 @@ void usage_with_options_internal(const char * const *usagestr,
 		case OPTION_STRING:
 			if (opts->argh) {
 				if (opts->flags & PARSE_OPT_OPTARG)
-					pos += fprintf(stderr, " [<%s>]", opts->argh);
+					if (opts->long_name)
+						pos += fprintf(stderr, "[=<%s>]", opts->argh);
+					else
+						pos += fprintf(stderr, "[<%s>]", opts->argh);
 				else
 					pos += fprintf(stderr, " <%s>", opts->argh);
 			} else {
 				if (opts->flags & PARSE_OPT_OPTARG)
-					pos += fprintf(stderr, " [...]");
+					if (opts->long_name)
+						pos += fprintf(stderr, "[=...]");
+					else
+						pos += fprintf(stderr, "[...]");
 				else
 					pos += fprintf(stderr, " ...");
 			}
diff --git a/t/t1502-rev-parse-parseopt.sh b/t/t1502-rev-parse-parseopt.sh
index d24a47d..3508d0a 100755
--- a/t/t1502-rev-parse-parseopt.sh
+++ b/t/t1502-rev-parse-parseopt.sh
@@ -13,7 +13,7 @@ usage: some-command [options] <args>...
     --bar ...             some cool option --bar with an argument
 
 An option group Header
-    -C [...]              option C with an optional argument
+    -C[...]               option C with an optional argument
 
 Extras
     --extra1              line above used to cause a segfault but no longer does
-- 
1.5.6