object-file: use unsigned arithmetic with bit mask

33f379eee6 (make object_directory.loose_objects_subdir_seen a bitmap,
2021-07-07) replaced a wasteful 256-byte array with a 32-byte array
and bit operations.  The mask calculation shifts a literal 1 of type
int left by anything between 0 and 31.  UndefinedBehaviorSanitizer
doesn't like that and reports:

object-file.c:2477:18: runtime error: left shift of 1 by 31 places cannot be represented in type 'int'

Make sure to use an unsigned 1 instead to avoid the issue.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/object-file.c b/object-file.c
index 35f3e7e9bb74c24ffa556f1a452983342671b6f2..dcb18592252d6442c11cea0b5615c6b702168495 100644 (file)
--- a/object-file.c
+++ b/object-file.c
@@ -2463,7 +2463,7 @@ struct oidtree *odb_loose_cache(struct object_directory *odb,
        struct strbuf buf = STRBUF_INIT;
        size_t word_bits = bitsizeof(odb->loose_objects_subdir_seen[0]);
        size_t word_index = subdir_nr / word_bits;
-       size_t mask = 1 << (subdir_nr % word_bits);
+       size_t mask = 1u << (subdir_nr % word_bits);
        uint32_t *bitmap;
 
        if (subdir_nr < 0 ||