[PATCH 3/3] shorten_unambiguous_ref(): tighten up pointer arithmetic

[Michael Haggerty <mhagger@alum.mit.edu>]

As long as we're being pathologically stingy with mallocs, we might as
well do the math right and save 6 (!) bytes.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
It is left to the reader to show how another 7 bytes could be saved
(11 bytes on a 64-bit architecture!)

It probably wouldn't kill performance to use a string_list here
instead.

 refs.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/refs.c b/refs.c
index ef9cdea..63b3a71 100644
--- a/refs.c
+++ b/refs.c
@@ -3351,10 +3351,10 @@ char *shorten_unambiguous_ref(const char *refname, int strict)
 		size_t total_len = 0;
 		size_t offset = 0;
 
-		/* the rule list is NULL terminated, count them first */
+		/* the rule list is NUL terminated, count them first */
 		for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
-			/* no +1 because strlen("%s") < strlen("%.*s") */
-			total_len += strlen(ref_rev_parse_rules[nr_rules]);
+			/* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
+			total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
 
 		scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
 
-- 
1.8.5.2