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Revision 78d9d414123ad6f4f522ffecbcd9e4a7562948fd authored by Linus Torvalds on 15 July 2005, 23:08:01 UTC, committed by Linus Torvalds on 15 July 2005, 23:08:01 UTC 
Ahh, the heady days of 0.99 patchfiles
 
Now, not all projects can be as refined as Linux.  Before the final 1.0
release, we went through fifteen 0.99 patchfiles, and pl14 alone went
through subreleases 'a' through 'z'. Now _that_ is a release process.

Not to mention the odd-ball releases, like 0.96c+

Sadly, in this day and age of RPM's etc, we have silly limitations, and
I cannot call this release '0.99pl5a or some such awe-inspiring name
just because "rpmbuild" is such a party pooper.  So it's just 0.99.1.

Oh well.  Aspiring to such greatness as the Linux release numbering is
hubris anyway.  You can attain such perfection only once in your life.
1 parent 71931c1
Raw File
patch-delta.c 
/*
 * patch-delta.c:
 * recreate a buffer from a source and the delta produced by diff-delta.c
 *
 * (C) 2005 Nicolas Pitre <nico@cam.org>
 *
 * This code is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <stdlib.h>
#include <string.h>
#include "delta.h"

void *patch_delta(void *src_buf, unsigned long src_size,
		  void *delta_buf, unsigned long delta_size,
		  unsigned long *dst_size)
{
	const unsigned char *data, *top;
	unsigned char *dst_buf, *out, cmd;
	unsigned long size;

	if (delta_size < DELTA_SIZE_MIN)
		return NULL;

	data = delta_buf;
	top = delta_buf + delta_size;

	/* make sure the orig file size matches what we expect */
	size = get_delta_hdr_size(&data);
	if (size != src_size)
		return NULL;

	/* now the result size */
	size = get_delta_hdr_size(&data);
	dst_buf = malloc(size);
	if (!dst_buf)
		return NULL;

	out = dst_buf;
	while (data < top) {
		cmd = *data++;
		if (cmd & 0x80) {
			unsigned long cp_off = 0, cp_size = 0;
			const unsigned char *buf;
			if (cmd & 0x01) cp_off = *data++;
			if (cmd & 0x02) cp_off |= (*data++ << 8);
			if (cmd & 0x04) cp_off |= (*data++ << 16);
			if (cmd & 0x08) cp_off |= (*data++ << 24);
			if (cmd & 0x10) cp_size = *data++;
			if (cmd & 0x20) cp_size |= (*data++ << 8);
			if (cp_size == 0) cp_size = 0x10000;
			buf = (cmd & 0x40) ? dst_buf : src_buf;
			memcpy(out, buf + cp_off, cp_size);
			out += cp_size;
		} else {
			memcpy(out, data, cmd);
			out += cmd;
			data += cmd;
		}
	}

	/* sanity check */
	if (data != top || out - dst_buf != size) {
		free(dst_buf);
		return NULL;
	}

	*dst_size = size;
	return dst_buf;
}
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