As we no longer use function pointers for read in common archiving code
archive_xread can be replaced with bb_full_read, and archive_copy_file
with bb_copyfd*
bb_copyfd is split into two functions bb_copyfd_size and bb_copyfd_eof,
they share a common backend.
diff --git a/archival/libunarchive/Makefile.in b/archival/libunarchive/Makefile.in
index c9dec09..09b0571 100644
--- a/archival/libunarchive/Makefile.in
+++ b/archival/libunarchive/Makefile.in
@@ -37,15 +37,12 @@
 	header_list.o \
 	header_verbose_list.o \
 \
-	archive_xread.o \
 	archive_xread_all.o \
 	archive_xread_all_eof.o \
 \
 	seek_by_char.o \
 	seek_by_jump.o \
 \
-	archive_copy_file.o \
-\
 	data_align.o \
 	find_list_entry.o \
 	open_transformer.o \
diff --git a/archival/libunarchive/archive_copy_file.c b/archival/libunarchive/archive_copy_file.c
deleted file mode 100644
index 675bc6f..0000000
--- a/archival/libunarchive/archive_copy_file.c
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- */
-
-#include <unistd.h>
-
-#include "libbb.h"
-#include "unarchive.h"
-
-extern void archive_copy_file(const archive_handle_t *archive_handle, const int dst_fd)
-{
-	char buffer[512];
-	off_t chunksize = archive_handle->file_header->size;
-
-	while (chunksize != 0) {
-		size_t size;
-		if (chunksize > 512) {
-			size = 512;
-		} else {
-			size = chunksize;
-		}
-//		archive_xread_all(archive_handle, buffer, size);
-		size = archive_xread(archive_handle, buffer, size);
-
-		if (write(dst_fd, buffer, size) != size) {
-			bb_error_msg_and_die ("Short write");
-		}
-		chunksize -= size;
-	}
-
-	return;
-}
diff --git a/archival/libunarchive/archive_xread.c b/archival/libunarchive/archive_xread.c
deleted file mode 100644
index 59b4d77..0000000
--- a/archival/libunarchive/archive_xread.c
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU Library General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include "unarchive.h"
-#include "libbb.h"
-
-extern ssize_t archive_xread(const archive_handle_t *archive_handle, unsigned char *buf, const size_t count)
-{
-	ssize_t size;
-
-	size = bb_full_read(archive_handle->src_fd, buf, count);
-	if (size < 0) {
-		bb_perror_msg_and_die("Read error");
-	}
-
-	return(size);
-}
diff --git a/archival/libunarchive/archive_xread_all.c b/archival/libunarchive/archive_xread_all.c
index cfe046b..ba9ade2 100644
--- a/archival/libunarchive/archive_xread_all.c
+++ b/archival/libunarchive/archive_xread_all.c
@@ -24,7 +24,7 @@
 {
 	ssize_t size;
 
-	size = archive_xread(archive_handle, buf, count);
+	size = bb_full_read(archive_handle->src_fd, buf, count);
 	if (size != count) {
 		bb_error_msg_and_die("Short read");
 	}
diff --git a/archival/libunarchive/archive_xread_all_eof.c b/archival/libunarchive/archive_xread_all_eof.c
index 23719cd..8084e35 100644
--- a/archival/libunarchive/archive_xread_all_eof.c
+++ b/archival/libunarchive/archive_xread_all_eof.c
@@ -24,7 +24,7 @@
 {
 	ssize_t size;
 
-	size = archive_xread(archive_handle, buf, count);
+	size = bb_full_read(archive_handle->src_fd, buf, count);
 	if ((size != 0) && (size != count)) {
 		bb_perror_msg_and_die("Short read, read %d of %d", size, count);
 	}
diff --git a/archival/libunarchive/data_extract_all.c b/archival/libunarchive/data_extract_all.c
index 4dccb81..bf3be5b 100644
--- a/archival/libunarchive/data_extract_all.c
+++ b/archival/libunarchive/data_extract_all.c
@@ -79,7 +79,7 @@
 			case S_IFREG: {
 				/* Regular file */
 				dst_fd = bb_xopen(file_header->name, O_WRONLY | O_CREAT | O_EXCL);
-				archive_copy_file(archive_handle, dst_fd);
+				bb_copyfd_size(archive_handle->src_fd, dst_fd, file_header->size);
 				close(dst_fd);
 				break;
 				}
diff --git a/archival/libunarchive/data_extract_to_stdout.c b/archival/libunarchive/data_extract_to_stdout.c
index 8be2fa2..ce5d4b8 100644
--- a/archival/libunarchive/data_extract_to_stdout.c
+++ b/archival/libunarchive/data_extract_to_stdout.c
@@ -18,5 +18,5 @@
 
 extern void data_extract_to_stdout(archive_handle_t *archive_handle)
 {
-	archive_copy_file(archive_handle, fileno(stdout));
+	bb_copyfd_eof(archive_handle->src_fd, fileno(stdout));
 }
diff --git a/archival/libunarchive/get_header_tar.c b/archival/libunarchive/get_header_tar.c
index d55189f..603535a 100644
--- a/archival/libunarchive/get_header_tar.c
+++ b/archival/libunarchive/get_header_tar.c
@@ -57,7 +57,7 @@
 	/* Align header */
 	data_align(archive_handle, 512);
 
-	if (archive_xread(archive_handle, tar.raw, 512) != 512) {
+	if (bb_full_read(archive_handle->src_fd, tar.raw, 512) != 512) {
 		/* Assume end of file */
 		return(EXIT_FAILURE);
 	}
diff --git a/archival/libunarchive/seek_by_char.c b/archival/libunarchive/seek_by_char.c
index 77da4ef..c031561 100644
--- a/archival/libunarchive/seek_by_char.c
+++ b/archival/libunarchive/seek_by_char.c
@@ -26,19 +26,7 @@
  */
 extern void seek_by_char(const archive_handle_t *archive_handle, const unsigned int jump_size)
 {
-	unsigned int remaining = jump_size;
-	unsigned int read_amount;
-	RESERVE_CONFIG_BUFFER(buf, BUFSIZ);
-
-	while (remaining > 0) {
-		if (remaining > BUFSIZ) {
-			read_amount = BUFSIZ;
-		} else {
-			read_amount = remaining;
-		}
-		read_amount = archive_xread(archive_handle, buf, read_amount);
-		remaining -= read_amount;
+	if (jump_size) {
+		bb_full_fd_action(archive_handle->src_fd, -1, jump_size, NULL);
 	}
-
-	RELEASE_CONFIG_BUFFER(buf);
 }