git/entry.c
Johannes Sixt 78a8d641c1 Add core.symlinks to mark filesystems that do not support symbolic links.
Some file systems that can host git repositories and their working copies
do not support symbolic links. But then if the repository contains a symbolic
link, it is impossible to check out the working copy.

This patch enables partial support of symbolic links so that it is possible
to check out a working copy on such a file system.  A new flag
core.symlinks (which is true by default) can be set to false to indicate
that the filesystem does not support symbolic links. In this case, symbolic
links that exist in the trees are checked out as small plain files, and
checking in modifications of these files preserve the symlink property in
the database (as long as an entry exists in the index).

Of course, this does not magically make symbolic links work on such defective
file systems; hence, this solution does not help if the working copy relies
on that an entry is a real symbolic link.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-02 16:58:05 -08:00

191 lines
4.4 KiB
C

#include "cache.h"
#include "blob.h"
static void create_directories(const char *path, struct checkout *state)
{
int len = strlen(path);
char *buf = xmalloc(len + 1);
const char *slash = path;
while ((slash = strchr(slash+1, '/')) != NULL) {
len = slash - path;
memcpy(buf, path, len);
buf[len] = 0;
if (mkdir(buf, 0777)) {
if (errno == EEXIST) {
struct stat st;
if (len > state->base_dir_len && state->force && !unlink(buf) && !mkdir(buf, 0777))
continue;
if (!stat(buf, &st) && S_ISDIR(st.st_mode))
continue; /* ok */
}
die("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("cannot opendir %s", path);
strcpy(pathbuf, path);
name = pathbuf + strlen(path);
*name++ = '/';
while ((de = readdir(dir)) != NULL) {
struct stat st;
if ((de->d_name[0] == '.') &&
((de->d_name[1] == 0) ||
((de->d_name[1] == '.') && de->d_name[2] == 0)))
continue;
strcpy(name, de->d_name);
if (lstat(pathbuf, &st))
die("cannot lstat %s", pathbuf);
if (S_ISDIR(st.st_mode))
remove_subtree(pathbuf);
else if (unlink(pathbuf))
die("cannot unlink %s", pathbuf);
}
closedir(dir);
if (rmdir(path))
die("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 int write_entry(struct cache_entry *ce, char *path, struct checkout *state, int to_tempfile)
{
int fd;
void *new;
unsigned long size;
long wrote;
enum object_type type;
new = read_sha1_file(ce->sha1, &type, &size);
if (!new || type != OBJ_BLOB) {
if (new)
free(new);
return error("git-checkout-index: unable to read sha1 file of %s (%s)",
path, sha1_to_hex(ce->sha1));
}
switch (ntohl(ce->ce_mode) & S_IFMT) {
char *buf;
unsigned long nsize;
case S_IFREG:
if (to_tempfile) {
strcpy(path, ".merge_file_XXXXXX");
fd = mkstemp(path);
} else
fd = create_file(path, ntohl(ce->ce_mode));
if (fd < 0) {
free(new);
return error("git-checkout-index: unable to create file %s (%s)",
path, strerror(errno));
}
/*
* Convert from git internal format to working tree format
*/
buf = new;
nsize = size;
if (convert_to_working_tree(ce->name, &buf, &nsize)) {
free(new);
new = buf;
size = nsize;
}
wrote = write_in_full(fd, new, size);
close(fd);
free(new);
if (wrote != size)
return error("git-checkout-index: unable to write file %s", path);
break;
case S_IFLNK:
if (to_tempfile || !has_symlinks) {
if (to_tempfile) {
strcpy(path, ".merge_link_XXXXXX");
fd = mkstemp(path);
} 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);
close(fd);
free(new);
if (wrote != size)
return error("git-checkout-index: unable to write file %s",
path);
} else {
wrote = symlink(new, path);
free(new);
if (wrote)
return error("git-checkout-index: unable to create "
"symlink %s (%s)", path, strerror(errno));
}
break;
default:
free(new);
return error("git-checkout-index: unknown file mode for %s", path);
}
if (state->refresh_cache) {
struct stat st;
lstat(ce->name, &st);
fill_stat_cache_info(ce, &st);
}
return 0;
}
int checkout_entry(struct cache_entry *ce, 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);
if (!lstat(path, &st)) {
unsigned changed = ce_match_stat(ce, &st, 1);
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)
*/
unlink(path);
if (S_ISDIR(st.st_mode)) {
if (!state->force)
return error("%s is a directory", path);
remove_subtree(path);
}
} else if (state->not_new)
return 0;
create_directories(path, state);
return write_entry(ce, path, state, 0);
}