git-commit-vandalism/builtin-commit-tree.c
Junio C Hamano 2295e8d0c4 commit-tree: do not overflow MAXPARENT
We have a static allocation of MAXPARENT, but that limit was not
enforced, other than by a lucky invocation of the program segfaulting.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-21 23:49:13 -08:00

140 lines
3.3 KiB
C

/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#include "cache.h"
#include "commit.h"
#include "tree.h"
#include "builtin.h"
#define BLOCKING (1ul << 14)
/*
* FIXME! Share the code with "write-tree.c"
*/
static void init_buffer(char **bufp, unsigned int *sizep)
{
char *buf = xmalloc(BLOCKING);
*sizep = 0;
*bufp = buf;
}
static void add_buffer(char **bufp, unsigned int *sizep, const char *fmt, ...)
{
char one_line[2048];
va_list args;
int len;
unsigned long alloc, size, newsize;
char *buf;
va_start(args, fmt);
len = vsnprintf(one_line, sizeof(one_line), fmt, args);
va_end(args);
size = *sizep;
newsize = size + len;
alloc = (size + 32767) & ~32767;
buf = *bufp;
if (newsize > alloc) {
alloc = (newsize + 32767) & ~32767;
buf = xrealloc(buf, alloc);
*bufp = buf;
}
*sizep = newsize;
memcpy(buf + size, one_line, len);
}
static void check_valid(unsigned char *sha1, const char *expect)
{
char type[20];
if (sha1_object_info(sha1, type, NULL))
die("%s is not a valid object", sha1_to_hex(sha1));
if (expect && strcmp(type, expect))
die("%s is not a valid '%s' object", sha1_to_hex(sha1),
expect);
}
/*
* Having more than two parents is not strange at all, and this is
* how multi-way merges are represented.
*/
#define MAXPARENT (16)
static unsigned char parent_sha1[MAXPARENT][20];
static const char commit_tree_usage[] = "git-commit-tree <sha1> [-p <sha1>]* < changelog";
static int new_parent(int idx)
{
int i;
unsigned char *sha1 = parent_sha1[idx];
for (i = 0; i < idx; i++) {
if (!hashcmp(parent_sha1[i], sha1)) {
error("duplicate parent %s ignored", sha1_to_hex(sha1));
return 0;
}
}
return 1;
}
int cmd_commit_tree(int argc, const char **argv, const char *prefix)
{
int i;
int parents = 0;
unsigned char tree_sha1[20];
unsigned char commit_sha1[20];
char comment[1000];
char *buffer;
unsigned int size;
setup_ident();
git_config(git_default_config);
if (argc < 2)
usage(commit_tree_usage);
if (get_sha1(argv[1], tree_sha1))
die("Not a valid object name %s", argv[1]);
check_valid(tree_sha1, tree_type);
for (i = 2; i < argc; i += 2) {
const char *a, *b;
a = argv[i]; b = argv[i+1];
if (!b || strcmp(a, "-p"))
usage(commit_tree_usage);
if (parents >= MAXPARENT)
die("Too many parents (%d max)", MAXPARENT);
if (get_sha1(b, parent_sha1[parents]))
die("Not a valid object name %s", b);
check_valid(parent_sha1[parents], commit_type);
if (new_parent(parents))
parents++;
}
init_buffer(&buffer, &size);
add_buffer(&buffer, &size, "tree %s\n", sha1_to_hex(tree_sha1));
/*
* NOTE! This ordering means that the same exact tree merged with a
* different order of parents will be a _different_ changeset even
* if everything else stays the same.
*/
for (i = 0; i < parents; i++)
add_buffer(&buffer, &size, "parent %s\n", sha1_to_hex(parent_sha1[i]));
/* Person/date information */
add_buffer(&buffer, &size, "author %s\n", git_author_info(1));
add_buffer(&buffer, &size, "committer %s\n\n", git_committer_info(1));
/* And add the comment */
while (fgets(comment, sizeof(comment), stdin) != NULL)
add_buffer(&buffer, &size, "%s", comment);
if (!write_sha1_file(buffer, size, commit_type, commit_sha1)) {
printf("%s\n", sha1_to_hex(commit_sha1));
return 0;
}
else
return 1;
}