open_transformer: do not return fd, it does not change

libbb: adopt zipped read from modprobe-small

function                                             old     new   delta
getoptscmd                                           708     713      +5
qgravechar                                           106     109      +3
huft_build                                          1165    1168      +3
tr_main                                              474     472      -2
open_transformer                                      91      89      -2
evalvar                                             1376    1374      -2
rpm_main                                            1691    1688      -3
qrealloc                                              36      33      -3
get_header_tar_lzma                                   55      52      -3
get_header_tar_gz                                    100      97      -3
get_header_tar_bz2                                    55      52      -3
get_header_tar_Z                                      89      86      -3
find_main                                            418     406     -12
prepare                                              302     283     -19
xmalloc_open_zipped_read_close                       161     135     -26
xmalloc_read                                         248     199     -49
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/13 up/down: 11/-130)         Total: -119 bytes

7 files changed, 15 insertions, 16 deletions

diff --git a/archival/libunarchive/Kbuild b/archival/libunarchive/Kbuild
index 1bc054a96..609bc50cb 100644
--- a/archival/libunarchive/Kbuild
+++ b/archival/libunarchive/Kbuild
@@ -43,6 +43,8 @@ lib-$(CONFIG_FEATURE_DEB_TAR_GZ)        += open_transformer.o
 lib-$(CONFIG_FEATURE_DEB_TAR_BZ2)       += open_transformer.o
 lib-$(CONFIG_FEATURE_DEB_TAR_LZMA)      += open_transformer.o
 
+lib-$(CONFIG_FEATURE_MODPROBE_SMALL_ZIPPED) += open_transformer.o decompress_unzip.o decompress_bunzip2.o
+
 lib-$(CONFIG_AR)                        += get_header_ar.o unpack_ar_archive.o
 lib-$(CONFIG_BUNZIP2)                   += decompress_bunzip2.o
 lib-$(CONFIG_UNLZMA)                    += decompress_unlzma.o
diff --git a/archival/libunarchive/get_header_tar_bz2.c b/archival/libunarchive/get_header_tar_bz2.c
index cfdc016d6..035c10bfb 100644
--- a/archival/libunarchive/get_header_tar_bz2.c
+++ b/archival/libunarchive/get_header_tar_bz2.c
@@ -11,7 +11,7 @@ char FAST_FUNC get_header_tar_bz2(archive_handle_t *archive_handle)
 	/* Can't lseek over pipes */
 	archive_handle->seek = seek_by_read;
 
-	archive_handle->src_fd = open_transformer(archive_handle->src_fd, unpack_bz2_stream, "bunzip2");
+	open_transformer(archive_handle->src_fd, unpack_bz2_stream, "bunzip2");
 	archive_handle->offset = 0;
 	while (get_header_tar(archive_handle) == EXIT_SUCCESS)
 		continue;
diff --git a/archival/libunarchive/get_header_tar_gz.c b/archival/libunarchive/get_header_tar_gz.c
index 33c62729e..086c6df42 100644
--- a/archival/libunarchive/get_header_tar_gz.c
+++ b/archival/libunarchive/get_header_tar_gz.c
@@ -25,7 +25,7 @@ char FAST_FUNC get_header_tar_gz(archive_handle_t *archive_handle)
 	}
 #endif
 
-	archive_handle->src_fd = open_transformer(archive_handle->src_fd, unpack_gz_stream, "gunzip");
+	open_transformer(archive_handle->src_fd, unpack_gz_stream, "gunzip");
 	archive_handle->offset = 0;
 	while (get_header_tar(archive_handle) == EXIT_SUCCESS)
 		continue;
diff --git a/archival/libunarchive/get_header_tar_lzma.c b/archival/libunarchive/get_header_tar_lzma.c
index 730c1b1bb..03b1b792d 100644
--- a/archival/libunarchive/get_header_tar_lzma.c
+++ b/archival/libunarchive/get_header_tar_lzma.c
@@ -14,7 +14,7 @@ char FAST_FUNC get_header_tar_lzma(archive_handle_t *archive_handle)
 	/* Can't lseek over pipes */
 	archive_handle->seek = seek_by_read;
 
-	archive_handle->src_fd = open_transformer(archive_handle->src_fd, unpack_lzma_stream, "unlzma");
+	open_transformer(archive_handle->src_fd, unpack_lzma_stream, "unlzma");
 	archive_handle->offset = 0;
 	while (get_header_tar(archive_handle) == EXIT_SUCCESS)
 		continue;
diff --git a/archival/libunarchive/open_transformer.c b/archival/libunarchive/open_transformer.c
index a5ee97167..42fdd96a6 100644
--- a/archival/libunarchive/open_transformer.c
+++ b/archival/libunarchive/open_transformer.c
@@ -11,7 +11,7 @@
  * On MMU machine, the transform_prog is removed by macro magic
  * in include/unarchive.h. On NOMMU, transformer is removed.
  */
-int FAST_FUNC open_transformer(int src_fd,
+void FAST_FUNC open_transformer(int fd,
 	USE_DESKTOP(long long) int FAST_FUNC (*transformer)(int src_fd, int dst_fd),
 	const char *transform_prog)
 {
@@ -32,20 +32,20 @@ int FAST_FUNC open_transformer(int src_fd,
 
 	if (pid == 0) {
 		/* child process */
-		close(fd_pipe.rd); /* We don't want to read from the parent */
+		close(fd_pipe.rd); /* we don't want to read from the parent */
 		// FIXME: error check?
 #if BB_MMU
-		transformer(src_fd, fd_pipe.wr);
+		transformer(fd, fd_pipe.wr);
 		if (ENABLE_FEATURE_CLEAN_UP) {
-			close(fd_pipe.wr); /* Send EOF */
-			close(src_fd);
+			close(fd_pipe.wr); /* send EOF */
+			close(fd);
 		}
 		/* must be _exit! bug was actually seen here */
 		_exit(EXIT_SUCCESS);
 #else
 		{
 			char *argv[4];
-			xmove_fd(src_fd, 0);
+			xmove_fd(fd, 0);
 			xmove_fd(fd_pipe.wr, 1);
 			argv[0] = (char*)transform_prog;
 			argv[1] = (char*)"-cf";
@@ -59,9 +59,6 @@ int FAST_FUNC open_transformer(int src_fd,
 	}
 
 	/* parent process */
-	close(fd_pipe.wr); /* Don't want to write to the child */
-
-//TODO: get rid of return value (become void)?
-	xmove_fd(fd_pipe.rd, src_fd);
-	return src_fd;
+	close(fd_pipe.wr); /* don't want to write to the child */
+	xmove_fd(fd_pipe.rd, fd);
 }
diff --git a/archival/rpm.c b/archival/rpm.c
index b3d7cd5f7..e6dd3d853 100644
--- a/archival/rpm.c
+++ b/archival/rpm.c
@@ -236,7 +236,7 @@ static void extract_cpio_gz(int fd)
 	}
 
 	xchdir("/"); /* Install RPM's to root */
-	archive_handle->src_fd = open_transformer(archive_handle->src_fd, xformer, xformer_prog);
+	open_transformer(archive_handle->src_fd, xformer, xformer_prog);
 	archive_handle->offset = 0;
 	while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
 		continue;
diff --git a/archival/tar.c b/archival/tar.c
index 13cdbd930..a46442f8e 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -692,7 +692,7 @@ static char FAST_FUNC get_header_tar_Z(archive_handle_t *archive_handle)
 		bb_error_msg_and_die("invalid magic");
 	}
 
-	archive_handle->src_fd = open_transformer(archive_handle->src_fd, uncompress, "uncompress");
+	open_transformer(archive_handle->src_fd, uncompress, "uncompress");
 	archive_handle->offset = 0;
 	while (get_header_tar(archive_handle) == EXIT_SUCCESS)
 		continue;