git/entry.c
Linus Torvalds b6986d8a75 git-checkout: be careful about untracked symlinks
This fixes the case where an untracked symlink that points at a directory
with tracked paths confuses the checkout logic, demostrated in t6035.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-29 20:24:28 -07:00

234 lines
5.8 KiB
C

#include "cache.h"
#include "blob.h"
#include "dir.h"
static void create_directories(const char *path, int path_len,
const struct checkout *state)
{
char *buf = xmalloc(path_len + 1);
int len = 0;
while (len < path_len) {
do {
buf[len] = path[len];
len++;
} while (len < path_len && path[len] != '/');
if (len >= path_len)
break;
buf[len] = 0;
/*
* For 'checkout-index --prefix=<dir>', <dir> is
* allowed to be a symlink to an existing directory,
* and we set 'state->base_dir_len' below, such that
* we test the path components of the prefix with the
* stat() function instead of the lstat() function.
*/
if (has_dirs_only_path(buf, len, state->base_dir_len))
continue; /* ok, it is already a directory. */
/*
* If this mkdir() would fail, it could be that there
* is already a symlink or something else exists
* there, therefore we then try to unlink it and try
* one more time to create the directory.
*/
if (mkdir(buf, 0777)) {
if (errno == EEXIST && state->force &&
!unlink_or_warn(buf) && !mkdir(buf, 0777))
continue;
die_errno("cannot create directory at '%s'", buf);
}
}
free(buf);
}
static void remove_subtree(const char *path)
{
DIR *dir = opendir(path);
struct dirent *de;
char pathbuf[PATH_MAX];
char *name;
if (!dir)
die_errno("cannot opendir '%s'", path);
strcpy(pathbuf, path);
name = pathbuf + strlen(path);
*name++ = '/';
while ((de = readdir(dir)) != NULL) {
struct stat st;
if (is_dot_or_dotdot(de->d_name))
continue;
strcpy(name, de->d_name);
if (lstat(pathbuf, &st))
die_errno("cannot lstat '%s'", pathbuf);
if (S_ISDIR(st.st_mode))
remove_subtree(pathbuf);
else if (unlink(pathbuf))
die_errno("cannot unlink '%s'", pathbuf);
}
closedir(dir);
if (rmdir(path))
die_errno("cannot rmdir '%s'", path);
}
static int create_file(const char *path, unsigned int mode)
{
mode = (mode & 0100) ? 0777 : 0666;
return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
}
static void *read_blob_entry(struct cache_entry *ce, unsigned long *size)
{
enum object_type type;
void *new = read_sha1_file(ce->sha1, &type, size);
if (new) {
if (type == OBJ_BLOB)
return new;
free(new);
}
return NULL;
}
static int write_entry(struct cache_entry *ce, char *path, const struct checkout *state, int to_tempfile)
{
unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
int fd, ret, fstat_done = 0;
char *new;
struct strbuf buf = STRBUF_INIT;
unsigned long size;
size_t wrote, newsize = 0;
struct stat st;
switch (ce_mode_s_ifmt) {
case S_IFREG:
case S_IFLNK:
new = read_blob_entry(ce, &size);
if (!new)
return error("git checkout-index: unable to read sha1 file of %s (%s)",
path, sha1_to_hex(ce->sha1));
if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
ret = symlink(new, path);
free(new);
if (ret)
return error("git checkout-index: unable to create symlink %s (%s)",
path, strerror(errno));
break;
}
/*
* Convert from git internal format to working tree format
*/
if (ce_mode_s_ifmt == S_IFREG &&
convert_to_working_tree(ce->name, new, size, &buf)) {
free(new);
new = strbuf_detach(&buf, &newsize);
size = newsize;
}
if (to_tempfile) {
if (ce_mode_s_ifmt == S_IFREG)
strcpy(path, ".merge_file_XXXXXX");
else
strcpy(path, ".merge_link_XXXXXX");
fd = mkstemp(path);
} else if (ce_mode_s_ifmt == S_IFREG) {
fd = create_file(path, ce->ce_mode);
} else {
fd = create_file(path, 0666);
}
if (fd < 0) {
free(new);
return error("git checkout-index: unable to create file %s (%s)",
path, strerror(errno));
}
wrote = write_in_full(fd, new, size);
/* use fstat() only when path == ce->name */
if (fstat_is_reliable() &&
state->refresh_cache && !to_tempfile && !state->base_dir_len) {
fstat(fd, &st);
fstat_done = 1;
}
close(fd);
free(new);
if (wrote != size)
return error("git checkout-index: unable to write file %s", path);
break;
case S_IFGITLINK:
if (to_tempfile)
return error("git checkout-index: cannot create temporary subproject %s", path);
if (mkdir(path, 0777) < 0)
return error("git checkout-index: cannot create subproject directory %s", path);
break;
default:
return error("git checkout-index: unknown file mode for %s", path);
}
if (state->refresh_cache) {
if (!fstat_done)
lstat(ce->name, &st);
fill_stat_cache_info(ce, &st);
}
return 0;
}
/*
* This is like 'lstat()', except it refuses to follow symlinks
* in the path.
*/
int check_path(const char *path, int len, struct stat *st)
{
if (has_symlink_leading_path(path, len)) {
errno = ENOENT;
return -1;
}
return lstat(path, st);
}
int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath)
{
static char path[PATH_MAX + 1];
struct stat st;
int len = state->base_dir_len;
if (topath)
return write_entry(ce, topath, state, 1);
memcpy(path, state->base_dir, len);
strcpy(path + len, ce->name);
len += ce_namelen(ce);
if (!check_path(path, len, &st)) {
unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID);
if (!changed)
return 0;
if (!state->force) {
if (!state->quiet)
fprintf(stderr, "git-checkout-index: %s already exists\n", path);
return -1;
}
/*
* We unlink the old file, to get the new one with the
* right permissions (including umask, which is nasty
* to emulate by hand - much easier to let the system
* just do the right thing)
*/
if (S_ISDIR(st.st_mode)) {
/* If it is a gitlink, leave it alone! */
if (S_ISGITLINK(ce->ce_mode))
return 0;
if (!state->force)
return error("%s is a directory", path);
remove_subtree(path);
} else if (unlink(path))
return error("unable to unlink old '%s' (%s)", path, strerror(errno));
} else if (state->not_new)
return 0;
create_directories(path, len, state);
return write_entry(ce, path, state, 0);
}