gpgtar: Fix extracting files with !(size % 512)

* tools/gpgtar-extract.c (extract_regular): Handle size multiples
  of RECORDSIZE.

--
  If a hdr->size was a multiple of 512 the last record would
  not have been written and the files corrupted accordingly.

GnuPG-bug-id: 1926

Signed-off-by: Andre Heinecke <aheinecke@intevation.de>

Changed to use only if-else.

Signed-off-by: Werner Koch <wk@gnupg.org>
(cherry picked from commit 6cbbb0bec9)

tools/gpgtar-extract.c

@@ -73,7 +73,11 @@ extract_regular (estream_t stream, const char *dirname,
       if (err)
         goto leave;
       n++;
-      nbytes = (n < hdr->nrecords)? RECORDSIZE : (hdr->size % RECORDSIZE);
+      if (n < hdr->nrecords || (hdr->size && !(hdr->size % RECORDSIZE)))
+        nbytes = RECORDSIZE;
+      else
+        nbytes = (hdr->size % RECORDSIZE);
+
       nwritten = es_fwrite (record, 1, nbytes, outfp);
       if (nwritten != nbytes)
         {