From: Tim Kientzle <kientzle@gmail.com>
Date: Fri, 9 Jan 2009 06:49:07 +0000 (-0500)
Subject: Fix Issue 3: http://code.google.com/p/libarchive/issues/detail?id=3
X-Git-Tag: v2.7.0~443
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=398d89f654892c63e8e1907a4e178c1eef3bf188;p=thirdparty%2Flibarchive.git

Fix Issue 3: http://code.google.com/p/libarchive/issues/detail?id=3

This occurs with Zip archives that have entries that are
compressed with deflate even though they are zero bytes
long.  Libarchive's zip handler returns a zero-byte block
from the decompression before returning end-of-entry.
Writing that zero-byte block back to the filesystem
triggered some code intended to catch misuse of the API.

The fix suppresses the warning in the case of a zero-byte
write request.

This is all very silly: compressing a zero-byte file is
a silly thing to do, libarchive's zip format handler is
returning a silly sequence of responses, and the warning
is silly.  Oh, well.  At least I fixed the warning. ;-)

SVN-Revision: 407
---

diff --git a/libarchive/archive_write_disk.c b/libarchive/archive_write_disk.c
index 5aa50c191..c1ddf77e7 100644
--- a/libarchive/archive_write_disk.c
+++ b/libarchive/archive_write_disk.c
@@ -519,6 +519,9 @@ write_data_block(struct archive_write_disk *a,
 	ssize_t bytes_written = 0;
 	ssize_t block_size = 0, bytes_to_write;
 
+	if (size == 0)
+		return (ARCHIVE_OK);
+
 	if (a->filesize == 0 || a->fd < 0) {
 		archive_set_error(&a->archive, 0,
 		    "Attempt to write to an empty file");