In archive_read_open(), do not set the internal archive state to

"HEADER" unless the open is successful.  Instead, leave the state as
"NEW."  In particular, if archive_read_open() fails, a subsequent call
to archive_read_next_header() will now cause an explicit assertion
failure instead of a silent segmentation fault.

This may need a little more work to fully realize the intention: If
archive_read_open() fails, you should be able to call it again on the
same archive handle to open a different archive (or the same archive
using a different mechanism).

1 files changed, 4 insertions, 2 deletions

diff --git a/lib/libarchive/archive_read.c b/lib/libarchive/archive_read.c
index 1d8f86d..5a1c114 100644
--- a/lib/libarchive/archive_read.c
+++ b/lib/libarchive/archive_read.c
@@ -126,8 +126,6 @@ archive_read_open(struct archive *a, void *client_data,
 	a->client_closer = closer;
 	a->client_data = client_data;
 
-	a->state = ARCHIVE_STATE_HEADER;
-
 	/* Open data source. */
 	if (a->client_opener != NULL) {
 		e =(a->client_opener)(a, a->client_data);
@@ -156,6 +154,10 @@ archive_read_open(struct archive *a, void *client_data,
 
 	/* Initialize decompression routine with the first block of data. */
 	e = (a->decompressors[high_bidder].init)(a, buffer, bytes_read);
+
+	if (e == ARCHIVE_OK)
+		a->state = ARCHIVE_STATE_HEADER;
+
 	return (e);
 }