[Bug-tar] Fix to sparse_diff_file when a sparse compare fails in 1.13.92

[Martin Simmons]

I've noticed that the code in sparse_diff_file calls skip_file in the success
case rather than the fail case, so never actually skips anything.


Test case (second tar should not print "Skipping to next header"):

perl -e 'open(S,">/tmp/sparse"); print S "foo"; seek S, 8192, 0; print S "foo"; 
close(S);'
tar -c --sparse -f /tmp/sparse.tar /tmp/sparse
perl -e 'open(S,">/tmp/sparse"); print S "bar"; seek S, 8192, 0; print S "foo"; 
close(S);'
tar --compare -f /tmp/sparse.tar --directory /


Patch:

--- orig/tar-1.13.92/src/sparse.c       2003-12-12 21:17:00.000000000 +0000
+++ tar-1.13.92/src/sparse.c    2003-12-27 21:05:25.000000000 +0000
@@ -489,7 +489,7 @@
                + file.stat_info->sparse_map[i].numbytes;
     }
 
-  if (rc)
+  if (!rc)
     skip_file (file.stat_info->archive_file_size - file.dumped_size);
 
   tar_sparse_done (&file);

__Martin