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>

diff --git a/diff.c b/diff.c
index 0391e8c..0f839c1 100644 (file)
--- 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.
         */

diff --git a/diffcore-rename.c b/diffcore-rename.c
index 6a9d95d..dba965c 100644 (file)
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -307,6 +307,9 @@ void diffcore_rename(struct diff_options *options)
        if (rename_count == rename_dst_nr)
                goto cleanup;
 
+       if (minimum_score == MAX_SCORE)
+               goto cleanup;
+
        num_create = (rename_dst_nr - rename_count);
        num_src = rename_src_nr;
        mx = xmalloc(sizeof(*mx) * num_create * num_src);