[git commit] rpm2cpio: extract cpio even if compression is not known

[Denys Vlasenko]

commit: https://git.busybox.net/busybox/commit/?id=f13f68288f45708ff12e0f6853def5910acd32c7
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

This is more useful than failing outright.

function                                             old     new   delta
rpm2cpio_main                                        110     144     +34
.rodata                                           105681  105715     +34
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 68/0)               Total: 68 bytes

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 archival/rpm.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/archival/rpm.c b/archival/rpm.c
index 7fd2a2b46..95a8c79b6 100644
--- a/archival/rpm.c
+++ b/archival/rpm.c
@@ -533,6 +533,7 @@ int rpm2cpio_main(int argc UNUSED_PARAM, char **argv)
 	//	/* We need to know whether child (gzip/bzip/etc) exits abnormally */
 	//	signal(SIGCHLD, check_errors_in_children);
 
+	str = NULL;
 	if (ENABLE_FEATURE_SEAMLESS_LZMA
 	 && (str = rpm_getstr0(TAG_PAYLOADCOMPRESSOR)) != NULL
 	 && strcmp(str, "lzma") == 0
@@ -541,7 +542,11 @@ int rpm2cpio_main(int argc UNUSED_PARAM, char **argv)
 		// set up decompressor without detection
 		setup_lzma_on_fd(rpm_fd);
 	} else {
-		setup_unzip_on_fd(rpm_fd, /*die_if_not_compressed:*/ 1);
+		int signature_bytes = setup_unzip_on_fd(rpm_fd, /*die_if_not_compressed:*/ 0);
+		if (signature_bytes != 0) {
+			xlseek(rpm_fd, - signature_bytes, SEEK_CUR);
+			bb_error_msg("warning, unknown compression '%s'", str);
+		}
 	}
 
 	if (bb_copyfd_eof(rpm_fd, STDOUT_FILENO) < 0)