[PATCH/RFC] rev-parse: stop interpreting flags as options to rev-parse once --flags is specified

[Jon Seymour <jon.seymour@gmail.com>]

Current git rev-parse behaviour makes --flags hard to use if the remaining
arguments to git rev-parse contain an option that would otherwise be interpreted
as an option by git rev-parse itself.

So, for example:

  $> git rev-parse --flags -q -X
  -X

Normally one might expect to use -- to prevent -q being interpreted:

  $> git rev-parse --flags -- -q -X
  -q -X

But we can't really use -- in this way, because commands that use
git rev-parse might reasonably expect:

  $> git rev-parse --flags -Y -- -q -X
  -Y

That is, -Y to be regarded as a flag but everything after -- to be uninterpreted.

This proposed change modifies git rev-parse so that git rev-parse stops
interpreting flag arguments as options to git rev-parse once --flags is
interpreted. We also exit early once -- is found.

Tests will follow in subsequent iterations of this patch, if the consensus
is that the approach is correct.

Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
---
 builtin/rev-parse.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index a5a1c86..9e340c7 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -497,8 +497,15 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 				/* Pass on the "--" if we show anything but files.. */
 				if (filter & (DO_FLAGS | DO_REVS))
 					show_file(arg);
+				if (!(filter & DO_NONFLAGS)) {
+					return 0;
+				}
 				continue;
 			}
+			if (!(filter & DO_NONFLAGS)) {
+				 show_flag(arg);
+				 continue;
+			}
 			if (!strcmp(arg, "--default")) {
 				def = argv[i+1];
 				i++;
-- 
1.7.2.14.gbde03.dirty