fix, request just the bare minimum for a WARC header

Moreover, assume a response of less than the bare minimum header
length to be the archive's EOF.

diff --git a/libarchive/archive_read_support_format_warc.c b/libarchive/archive_read_support_format_warc.c
index 62372a2190e5a20b3cc5bd8413af16290c180dee..0e69d0b3e78980c67df7e405f6d34116c06a8428 100644 (file)
--- a/libarchive/archive_read_support_format_warc.c
+++ b/libarchive/archive_read_support_format_warc.c
@@ -180,7 +180,7 @@ _warc_bid(struct archive_read *a, int best_bid)
 static int
 _warc_rdhdr(struct archive_read *a, struct archive_entry *entry)
 {
-#define HDR_PROBE_LEN          (512U)
+#define HDR_PROBE_LEN          (12U)
        struct warc_s *w = a->format->data;
        unsigned int ver;
        const char *buf;
@@ -199,13 +199,13 @@ start_over:
         * and reproduce that functionality here */
        buf = __archive_read_ahead(a, HDR_PROBE_LEN, &nrd);
 
-       if (nrd < 0 || buf == NULL) {
+       if (nrd < 0) {
                /* no good */
                archive_set_error(
                        &a->archive, ARCHIVE_ERRNO_MISC,
                        "Bad record header");
                return (ARCHIVE_FATAL);
-       } else if (nrd < 12U) {
+       } else if (nrd < 12U || buf == NULL) {
                /* there should be room for at least WARC/bla\r\n
                 * must be EOF therefore */
                return (ARCHIVE_EOF);