rename detection with -M100 means "exact renames only".

When the user is interested in pure renames, there is no point
doing the similarity scores.  This changes the score argument
parsing to special case -M100 (otherwise, it is a precision
scaled value 0 <= v < 1 and would mean 0.1, not 1.0 --- if you
do mean 0.1, you can say -M1), and optimizes the diffcore_rename
transformation to only look at pure renames in that case.

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

1 files changed, 4 insertions, 0 deletions

diff --git a/diff.c b/diff.c
index 0391e8c423..0f839c11b7 100644
--- a/diff.c
+++ b/diff.c
@@ -853,6 +853,10 @@ static int parse_num(const char **cp_p)
 	}
 	*cp_p = cp;
 
+	/* special case: -M100 would mean 1.0 not 0.1 */
+	if (num == 100 && scale == 1000)
+		return MAX_SCORE;
+
 	/* user says num divided by scale and we say internally that
 	 * is MAX_SCORE * num / scale.
 	 */