Stackable write filter support. This ended up touching an awful lot

of files.  But, the old API is supported almost entirely unchanged, which
I wasn't certain would be possible.

Big changes:
  * You can add more than one write filter by using
    archive_write_add_filter_{bzip2,compress,gzip,lzma,xz}.
    This will be more interesting when we have uuencode, RPM, encryption.
  * The old archive_write_set_compression_XXXX are shorthands for
    "remove all the current filters and add this one."  They're
    deprecated and scheduled to be removed in libarchive 4.0.
  * The internal API and life cycle for write filters has been
    rationalized: create, set options, open, write, close, free.
  * New utility functions provide information about each filter
    when there's more than one:  code, name, and number of bytes processed
  * Old archive_bytes_compressed(), etc, are implemented in terms of
    the more generic new functions.
  * The read side was generalized to also support the new utility
    functions.

In particular, the write filters are much simpler since each
one doesn't have to deal with blocking.  In this version, there's
still a "write_add_filter_none" that handles blocking, but I
think I'll soon fold that down into the client wrapper and
add_filter_none will become a no-op.  I think this also gets
us a big step closer to multi-volume support on the write side.

SVN-Revision: 1920

1 files changed, 3 insertions, 1 deletions

diff --git a/libarchive/archive_read_support_format_ar.c b/libarchive/archive_read_support_format_ar.c
index 7c1ca3a0..80c014a1 100644
--- a/libarchive/archive_read_support_format_ar.c
+++ b/libarchive/archive_read_support_format_ar.c
@@ -55,6 +55,7 @@ struct ar {
 	off_t	 entry_padding;
 	char	*strtab;
 	size_t	 strtab_size;
+	char	 read_global_header;
 };
 
 /*
@@ -172,12 +173,13 @@ archive_read_format_ar_read_header(struct archive_read *a,
 
 	ar = (struct ar*)(a->format->data);
 
-	if (a->archive.file_position == 0) {
+	if (!ar->read_global_header) {
 		/*
 		 * We are now at the beginning of the archive,
 		 * so we need first consume the ar global header.
 		 */
 		__archive_read_consume(a, 8);
+		ar->read_global_header = 1;
 		/* Set a default format code for now. */
 		a->archive.archive_format = ARCHIVE_FORMAT_AR;
 	}