isl_mat_drop_cols: special case dropping of zero columns

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>

diff --git a/isl_mat.c b/isl_mat.c
index cff8123..16a79f7 100644 (file)
--- a/isl_mat.c
+++ b/isl_mat.c
@@ -1245,6 +1245,9 @@ struct isl_mat *isl_mat_drop_cols(struct isl_mat *mat, unsigned col, unsigned n)
 {
        int r;
 
+       if (n == 0)
+               return mat;
+
        mat = isl_mat_cow(mat);
        if (!mat)
                return NULL;