git/builtin/merge-recursive.c
Jeff King 5096d4909f convert trivial sprintf / strcpy calls to xsnprintf
We sometimes sprintf into fixed-size buffers when we know
that the buffer is large enough to fit the input (either
because it's a constant, or because it's numeric input that
is bounded in size). Likewise with strcpy of constant
strings.

However, these sites make it hard to audit sprintf and
strcpy calls for buffer overflows, as a reader has to
cross-reference the size of the array with the input. Let's
use xsnprintf instead, which communicates to a reader that
we don't expect this to overflow (and catches the mistake in
case we do).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-25 10:18:18 -07:00

81 lines
2.0 KiB
C

#include "builtin.h"
#include "commit.h"
#include "tag.h"
#include "merge-recursive.h"
#include "xdiff-interface.h"
static const char builtin_merge_recursive_usage[] =
"git %s <base>... -- <head> <remote> ...";
static const char *better_branch_name(const char *branch)
{
static char githead_env[8 + 40 + 1];
char *name;
if (strlen(branch) != 40)
return branch;
xsnprintf(githead_env, sizeof(githead_env), "GITHEAD_%s", branch);
name = getenv(githead_env);
return name ? name : branch;
}
int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
{
const unsigned char *bases[21];
unsigned bases_count = 0;
int i, failed;
unsigned char h1[20], h2[20];
struct merge_options o;
struct commit *result;
init_merge_options(&o);
if (argv[0] && ends_with(argv[0], "-subtree"))
o.subtree_shift = "";
if (argc < 4)
usagef(builtin_merge_recursive_usage, argv[0]);
for (i = 1; i < argc; ++i) {
const char *arg = argv[i];
if (starts_with(arg, "--")) {
if (!arg[2])
break;
if (parse_merge_opt(&o, arg + 2))
die("Unknown option %s", arg);
continue;
}
if (bases_count < ARRAY_SIZE(bases)-1) {
unsigned char *sha = xmalloc(20);
if (get_sha1(argv[i], sha))
die("Could not parse object '%s'", argv[i]);
bases[bases_count++] = sha;
}
else
warning("Cannot handle more than %d bases. "
"Ignoring %s.",
(int)ARRAY_SIZE(bases)-1, argv[i]);
}
if (argc - i != 3) /* "--" "<head>" "<remote>" */
die("Not handling anything other than two heads merge.");
o.branch1 = argv[++i];
o.branch2 = argv[++i];
if (get_sha1(o.branch1, h1))
die("Could not resolve ref '%s'", o.branch1);
if (get_sha1(o.branch2, h2))
die("Could not resolve ref '%s'", o.branch2);
o.branch1 = better_branch_name(o.branch1);
o.branch2 = better_branch_name(o.branch2);
if (o.verbosity >= 3)
printf("Merging %s with %s\n", o.branch1, o.branch2);
failed = merge_recursive_generic(&o, h1, h2, bases_count, bases, &result);
if (failed < 0)
return 128; /* die() error code */
return failed;
}