fix, never write more bytes in _warc_data() than ...

previously announce in _warc_header().

The test suite (as is) is one offender.  It populates a 9-byte string, mimicking an IFREG file
but by the time the header makes it into the archive, the size changes from 0 to 9.

diff --git a/libarchive/archive_write_set_format_warc.c b/libarchive/archive_write_set_format_warc.c
index 6c7b8c7eece2c97b17b68c21d285ea976b50fc56..82c603eedb7e59644de4eeac89d118084ef3fcab 100644 (file)
--- a/libarchive/archive_write_set_format_warc.c
+++ b/libarchive/archive_write_set_format_warc.c
@@ -54,6 +54,8 @@ struct warc_s {
        time_t now;
        mode_t typ;
        unsigned int rng;
+       /* populated size */
+       size_t populz;
 };
 
 static const char warcinfo[] = "\
@@ -213,6 +215,7 @@ _warc_header(struct archive_write *a, struct archive_entry *entry)
        }
 
        w->typ = archive_entry_filetype(entry);
+       w->populz = 0U;
        if (w->typ == AE_IFREG) {
                warc_essential_hdr_t rh = {
                        WT_RSRC,
@@ -235,6 +238,8 @@ _warc_header(struct archive_write *a, struct archive_entry *entry)
                }
                /* otherwise append to output stream */
                __archive_write_output(a, hdr, r);
+               /* and let subsequent calls to _data() know about the size */
+               w->populz = rh.cntlen;
        }
        /* just pretend it's all good */
        return (ARCHIVE_OK);
@@ -246,8 +251,15 @@ _warc_data(struct archive_write *a, const void *buf, size_t len)
        struct warc_s *w = a->format_data;
 
        if (w->typ == AE_IFREG) {
-               int rc = __archive_write_output(a, buf, len);
+               int rc;
 
+               /* never write more bytes than announced */
+               if (len > w->populz) {
+                       len = w->populz;
+               }
+
+               /* now then, out we put the whole shebang */
+               rc = __archive_write_output(a, buf, len);
                if (rc != ARCHIVE_OK) {
                        return rc;
                }