Fix 64-bit build warning
diff --git a/src/attr_file.c b/src/attr_file.c
index 4409d74..49ff731 100644
--- a/src/attr_file.c
+++ b/src/attr_file.c
@@ -35,7 +35,7 @@ int git_attr_file__new(
if (path) {
size_t len = strlen(path);
- attrs->key = git_pool_malloc(attrs->pool, len + 3);
+ attrs->key = git_pool_malloc(attrs->pool, (uint32_t)len + 3);
GITERR_CHECK_ALLOC(attrs->key);
attrs->key[0] = '0' + from;