Fix `--test-label' and `--label -r' behavior.

[chaz/tar] / src / buffer.c

diff --git a/src/buffer.c b/src/buffer.c
index f419dd7bcb357232ca76f254a78417c0a6794142..8e1bb9b24aea0dcbd51851cf5213ea3757ea4921 100644 (file)
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -201,6 +201,7 @@ enum compress_type {
   ct_compress,
   ct_gzip,
   ct_bzip2,
+  ct_lzip,
   ct_lzma,
   ct_lzop,
   ct_xz
@@ -221,6 +222,7 @@ static struct zip_magic const magic[] = {
   { ct_compress, 2, "\037\235",  COMPRESS_PROGRAM, "-Z" },
   { ct_gzip,     2, "\037\213",  GZIP_PROGRAM,     "-z"  },
   { ct_bzip2,    3, "BZh",       BZIP2_PROGRAM,    "-j" },
+  { ct_lzip,     4, "LZIP",      LZIP_PROGRAM,     "--lzip" },
   { ct_lzma,     6, "\xFFLZMA",  LZMA_PROGRAM,     "--lzma" },
   { ct_lzop,     4, "\211LZO",   LZOP_PROGRAM,     "--lzop" },
   { ct_xz,       6, "\0xFD7zXZ", XZ_PROGRAM,       "-J" },
@@ -854,16 +856,16 @@ seek_archive (off_t size)
   off_t start = current_block_ordinal ();
   off_t offset;
   off_t nrec, nblk;
-  off_t skipped = (blocking_factor - (current_block - record_start));
+  off_t skipped = (blocking_factor - (current_block - record_start))
+                  * BLOCKSIZE;
 
-  size -= skipped * BLOCKSIZE;
-
-  if (size < record_size)
+  if (size <= skipped)
     return 0;
-  /* FIXME: flush? */
-
+  
   /* Compute number of records to skip */
-  nrec = size / record_size;
+  nrec = (size - skipped) / record_size;
+  if (nrec == 0)
+    return 0;
   offset = rmtlseek (archive, nrec * record_size, SEEK_CUR);
   if (offset < 0)
     return offset;
@@ -1165,7 +1167,7 @@ read_header0 (struct tar_stat_info *info)
   enum read_header rc;
 
   tar_stat_init (info);
-  rc = read_header (&current_header, info, false);
+  rc = read_header (&current_header, info, read_header_auto);
   if (rc == HEADER_SUCCESS)
     {
       set_next_block_after (current_header);
@@ -1213,17 +1215,42 @@ try_new_volume ()
     {
     case XGLTYPE:
       {
-        if (!read_header0 (&dummy))
-          return false;
+       tar_stat_init (&dummy);
+       if (read_header (&header, &dummy, read_header_x_global)
+           != HEADER_SUCCESS_EXTENDED)
+         {
+           ERROR ((0, 0, _("This does not look like a tar archive")));
+           return false;
+         }
+       
         xheader_decode (&dummy); /* decodes values from the global header */
         tar_stat_destroy (&dummy);
-        if (!real_s_name)
-          {
-            /* We have read the extended header of the first member in
-               this volume. Put it back, so next read_header works as
-               expected. */
-            current_block = record_start;
-          }
+       
+       /* The initial global header must be immediately followed by
+          an extended PAX header for the first member in this volume.
+          However, in some cases tar may split volumes in the middle
+          of a PAX header. This is incorrect, and should be fixed
+           in the future versions. In the meantime we must be
+          prepared to correctly list and extract such archives.
+
+          If this happens, the following call to read_header returns
+          HEADER_FAILURE, which is ignored.
+
+          See also tests/multiv07.at */
+              
+       switch (read_header (&header, &dummy, read_header_auto))
+         {
+         case HEADER_SUCCESS:
+           set_next_block_after (header);
+           break;
+
+         case HEADER_FAILURE:
+           break;
+
+         default:
+           ERROR ((0, 0, _("This does not look like a tar archive")));
+           return false;
+         }
         break;
       }
 
@@ -1814,6 +1841,7 @@ open_archive (enum access_mode wanted_access)
   switch (wanted_access)
     {
     case ACCESS_READ:
+    case ACCESS_UPDATE:
       if (volume_label_option)
         match_volume_label ();
       break;
@@ -1823,9 +1851,6 @@ open_archive (enum access_mode wanted_access)
       if (volume_label_option)
         write_volume_label ();
       break;
-
-    default:
-      break;
     }
   set_volume_start_time ();
 }