[PATCH/RFC 1/4] Add "-" as @{-1} support for the rev-parse command

[Kenny Lee Sin Cheong <kenny.lee28@gmail.com>]

Allows the use of the "-" shorthand notation, including
use with revision ranges. If we plan to allow "-" as a stand in every
where a revision is allowed, then "-" would also need to be usable in
plumbing commands, for writing tests, for example.

Checks if the argument can be interpreted as a revision range first
before checking for flags. This saves us from having to check that
something that begins with "-" does not get checked as a possible flag.

Signed-off-by: Kenny Lee Sin Cheong <kenny.lee28@gmail.com>
---
 builtin/rev-parse.c | 37 +++++++++++++++++++------------------
 1 file changed, 19 insertions(+), 18 deletions(-)

diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 3626c61..8da95b5 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -553,6 +553,25 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 			continue;
 		}
 
+		/* Not a flag argument */
+		if (try_difference(arg))
+			continue;
+		if (try_parent_shorthands(arg))
+			continue;
+		name = arg;
+		type = NORMAL;
+		if (*arg == '^') {
+			name++;
+			type = REVERSED;
+		}
+		if (!get_sha1_with_context(name, flags, sha1, &unused)) {
+			if (verify)
+				revs_count++;
+			else
+				show_rev(type, sha1, name);
+			continue;
+		}
+
 		if (*arg == '-') {
 			if (!strcmp(arg, "--")) {
 				as_is = 2;
@@ -810,24 +829,6 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 			continue;
 		}
 
-		/* Not a flag argument */
-		if (try_difference(arg))
-			continue;
-		if (try_parent_shorthands(arg))
-			continue;
-		name = arg;
-		type = NORMAL;
-		if (*arg == '^') {
-			name++;
-			type = REVERSED;
-		}
-		if (!get_sha1_with_context(name, flags, sha1, &unused)) {
-			if (verify)
-				revs_count++;
-			else
-				show_rev(type, sha1, name);
-			continue;
-		}
 		if (verify)
 			die_no_single_rev(quiet);
 		if (has_dashdash)
-- 
2.3.3.203.g8ffb468.dirty