revision arguments: ..B means HEAD..B, just like A.. means A..HEAD

For consistency reasons, we should probably allow that to be written as
just "..branch", the same way we can write "branch.." to mean "everything
in HEAD but not in "branch".

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 10 insertions, 9 deletions

diff --git a/rev-parse.c b/rev-parse.c
index f176c56f7..e956cd5ed 100644
--- a/rev-parse.c
+++ b/rev-parse.c
@@ -315,16 +315,17 @@ int main(int argc, char **argv)
 		dotdot = strstr(arg, "..");
 		if (dotdot) {
 			unsigned char end[20];
-			char *n = dotdot+2;
+			char *next = dotdot + 2;
+			char *this = arg;
 			*dotdot = 0;
-			if (!get_sha1(arg, sha1)) {
-				if (!*n)
-					n = "HEAD";
-				if (!get_sha1(n, end)) {
-					show_rev(NORMAL, end, n);
-					show_rev(REVERSED, sha1, arg);
-					continue;
-				}
+			if (!*next)
+				next = "HEAD";
+			if (dotdot == arg)
+				this = "HEAD";
+			if (!get_sha1(this, sha1) && !get_sha1(next, end)) {
+				show_rev(NORMAL, end, next);
+				show_rev(REVERSED, sha1, this);
+				continue;
 			}
 			*dotdot = '.';
 		}