Fill out diff rename test coverage

This extends the rename tests to make sure that every rename
scenario in the inner loop of git_diff_find_similar is actually
exercised.  Also, fixes an incorrect assert that was in one of
the clauses that was not previously being exercised.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/diff_tform.c b/src/diff_tform.c
index 0f4ecc7b5..bc3acae1d 100644
--- a/src/diff_tform.c
+++ b/src/diff_tform.c
@@ -776,7 +776,7 @@ int git_diff_find_similar(
 
 				num_rewrites++;
 			} else {
-				assert(delta_is_split(from));
+				assert(delta_is_split(to));
 
 				if (similarity < (int)opts.rename_from_rewrite_threshold)
 					continue;