[pacman-dev] [PATCH] libalpm: Use archive_read_extract2

[Armin K]

archive_read_extract() forces resolution of uid/gid to names
when extracting the tarball. This can lead to wrong file
ownership when using pacman with -r option and when uid/gid
differ in the host and in the chroot.

archive_read_extract2() uses uid's and gid's only. See also:

https://lists.archlinux.org/pipermail/pacman-dev/2017-March/021912.html

Signed-off-by: Armin K <krejzi at email.com>
---
 lib/libalpm/add.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/libalpm/add.c b/lib/libalpm/add.c
index c5bed817..0beed01c 100644
--- a/lib/libalpm/add.c
+++ b/lib/libalpm/add.c
@@ -110,6 +110,7 @@ static int perform_extraction(alpm_handle_t *handle, struct archive *archive,
 		struct archive_entry *entry, const char *filename)
 {
 	int ret;
+	struct archive *archive_writer;
 	const int archive_flags = ARCHIVE_EXTRACT_OWNER |
 	                          ARCHIVE_EXTRACT_PERM |
 	                          ARCHIVE_EXTRACT_TIME |
@@ -118,7 +119,20 @@ static int perform_extraction(alpm_handle_t *handle, struct archive *archive,
 
 	archive_entry_set_pathname(entry, filename);
 
-	ret = archive_read_extract(archive, entry, archive_flags);
+	archive_writer = archive_write_disk_new();
+	if (archive_writer == NULL) {
+		_alpm_log(handle, ALPM_LOG_ERROR, _("cannot allocate disk archive object"));
+		alpm_logaction(handle, ALPM_CALLER_PREFIX,
+				"error: cannot allocate disk archive object");
+		return 1;
+	}
+
+	archive_write_disk_set_options(archive_writer, archive_flags);
+
+	ret = archive_read_extract2(archive, entry, archive_writer);
+
+	archive_write_free(archive_writer);
+
 	if(ret == ARCHIVE_WARN && archive_errno(archive) != ENOSPC) {
 		/* operation succeeded but a "non-critical" error was encountered */
 		_alpm_log(handle, ALPM_LOG_WARNING, _("warning given when extracting %s (%s)\n"),
-- 
2.12.0