mirror of
https://github.com/git/git
synced 2024-08-24 18:26:02 +00:00
![Florian Forster](/assets/img/avatar_default.png)
ANSI C99 doesn't allow void-pointer arithmetic. This patch fixes this in various ways. Usually the strategy that required the least changes was used. Signed-off-by: Florian Forster <octo@verplant.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
89 lines
2.1 KiB
C
89 lines
2.1 KiB
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(const void *src_buf, unsigned long src_size,
|
|
const 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 = (const unsigned char *) delta_buf + delta_size;
|
|
|
|
/* make sure the orig file size matches what we expect */
|
|
size = get_delta_hdr_size(&data, top);
|
|
if (size != src_size)
|
|
return NULL;
|
|
|
|
/* now the result size */
|
|
size = get_delta_hdr_size(&data, top);
|
|
dst_buf = malloc(size + 1);
|
|
if (!dst_buf)
|
|
return NULL;
|
|
dst_buf[size] = 0;
|
|
|
|
out = dst_buf;
|
|
while (data < top) {
|
|
cmd = *data++;
|
|
if (cmd & 0x80) {
|
|
unsigned long cp_off = 0, cp_size = 0;
|
|
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 (cmd & 0x40) cp_size |= (*data++ << 16);
|
|
if (cp_size == 0) cp_size = 0x10000;
|
|
if (cp_off + cp_size < cp_size ||
|
|
cp_off + cp_size > src_size ||
|
|
cp_size > size)
|
|
goto bad;
|
|
memcpy(out, (char *) src_buf + cp_off, cp_size);
|
|
out += cp_size;
|
|
size -= cp_size;
|
|
} else if (cmd) {
|
|
if (cmd > size)
|
|
goto bad;
|
|
memcpy(out, data, cmd);
|
|
out += cmd;
|
|
data += cmd;
|
|
size -= cmd;
|
|
} else {
|
|
/*
|
|
* cmd == 0 is reserved for future encoding
|
|
* extensions. In the mean time we must fail when
|
|
* encountering them (might be data corruption).
|
|
*/
|
|
goto bad;
|
|
}
|
|
}
|
|
|
|
/* sanity check */
|
|
if (data != top || size != 0) {
|
|
bad:
|
|
free(dst_buf);
|
|
return NULL;
|
|
}
|
|
|
|
*dst_size = out - dst_buf;
|
|
return dst_buf;
|
|
}
|