Fix build failure with gcc.

diff --git a/libarchive/archive_write_set_format_warc.c b/libarchive/archive_write_set_format_warc.c
index 9623d717feb7bd876c9f27c33dfaa691cb365791..c4416ec1ce9d2d64aad8fc24e5da6c2fa9b365da 100644 (file)
--- a/libarchive/archive_write_set_format_warc.c
+++ b/libarchive/archive_write_set_format_warc.c
@@ -421,7 +421,7 @@ _popul_ehdr(struct archive_string *tgt, size_t tsz, warc_essential_hdr_t hdr)
        /**/
        archive_strncat(tgt, "\r\n", 2);
 
-       return (archive_strlen(tgt) >= tsz)? -1: archive_strlen(tgt);
+       return (archive_strlen(tgt) >= tsz)? -1: (ssize_t)archive_strlen(tgt);
 }
 
 static int