Revision b3f01ff29f7131e959bcfdfd004744d74d5fa319 authored by Junio C Hamano on 01 March 2012, 02:14:16 UTC, committed by Junio C Hamano on 01 March 2012, 20:00:01 UTC
The plumbing "diff" commands look at the working tree files without refreshing the index themselves for performance reasons (the calling script is expected to do that upfront just once, before calling one or more of them). In the early days of git, they showed the "diff --git" header before they actually ask the xdiff machinery to produce patches, and ended up showing only these headers if the real contents are the same and the difference they noticed was only because the stat info cached in the index did not match that of the working tree. It was too late for the implementation to take the header that it already emitted back. But 3e97c7c (No diff -b/-w output for all-whitespace changes, 2009-11-19) introduced necessary logic to keep the meta-information headers in a strbuf and delay their output until the xdiff machinery noticed actual changes. This was primarily in order to generate patches that ignore whitespaces. When operating under "-w" mode, we wouldn't know if the header is needed until we actually look at the resulting patch, so it was a sensible thing to do, but we did not realize that the same reasoning applies to stat-dirty paths. Later, 296c6bb (diff: fix "git show -C -C" output when renaming a binary file, 2010-05-26) generalized this machinery and added must_show_header toggle. This is turned on when the header must be shown even when there is no patch to be produced, e.g. only the mode was changed, or the path was renamed, without changing the contents. However, when it did so, it still kept the special case for the "-w" mode, which meant that the plumbing would keep showing these phantom changes. This corrects this historical inconsistency by allowing the plumbing to omit paths that are only stat-dirty from its output in the same way as it handles whitespace only changes under "-w" option. The change in the behaviour can be seen in the updated test. Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 5597e84
path.c
/*
* I'm tired of doing "vsnprintf()" etc just to open a
* file, so here's a "return static buffer with printf"
* interface for paths.
*
* It's obviously not thread-safe. Sue me. But it's quite
* useful for doing things like
*
* f = open(mkpath("%s/%s.git", base, name), O_RDONLY);
*
* which is what it's designed for.
*/
#include "cache.h"
#include "strbuf.h"
static char bad_path[] = "/bad-path/";
static char *get_pathname(void)
{
static char pathname_array[4][PATH_MAX];
static int index;
return pathname_array[3 & ++index];
}
static char *cleanup_path(char *path)
{
/* Clean it up */
if (!memcmp(path, "./", 2)) {
path += 2;
while (*path == '/')
path++;
}
return path;
}
char *mksnpath(char *buf, size_t n, const char *fmt, ...)
{
va_list args;
unsigned len;
va_start(args, fmt);
len = vsnprintf(buf, n, fmt, args);
va_end(args);
if (len >= n) {
strlcpy(buf, bad_path, n);
return buf;
}
return cleanup_path(buf);
}
static char *git_vsnpath(char *buf, size_t n, const char *fmt, va_list args)
{
const char *git_dir = get_git_dir();
size_t len;
len = strlen(git_dir);
if (n < len + 1)
goto bad;
memcpy(buf, git_dir, len);
if (len && !is_dir_sep(git_dir[len-1]))
buf[len++] = '/';
len += vsnprintf(buf + len, n - len, fmt, args);
if (len >= n)
goto bad;
return cleanup_path(buf);
bad:
strlcpy(buf, bad_path, n);
return buf;
}
char *git_snpath(char *buf, size_t n, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
(void)git_vsnpath(buf, n, fmt, args);
va_end(args);
return buf;
}
char *git_pathdup(const char *fmt, ...)
{
char path[PATH_MAX];
va_list args;
va_start(args, fmt);
(void)git_vsnpath(path, sizeof(path), fmt, args);
va_end(args);
return xstrdup(path);
}
char *mkpath(const char *fmt, ...)
{
va_list args;
unsigned len;
char *pathname = get_pathname();
va_start(args, fmt);
len = vsnprintf(pathname, PATH_MAX, fmt, args);
va_end(args);
if (len >= PATH_MAX)
return bad_path;
return cleanup_path(pathname);
}
char *git_path(const char *fmt, ...)
{
const char *git_dir = get_git_dir();
char *pathname = get_pathname();
va_list args;
unsigned len;
len = strlen(git_dir);
if (len > PATH_MAX-100)
return bad_path;
memcpy(pathname, git_dir, len);
if (len && git_dir[len-1] != '/')
pathname[len++] = '/';
va_start(args, fmt);
len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
va_end(args);
if (len >= PATH_MAX)
return bad_path;
return cleanup_path(pathname);
}
char *git_path_submodule(const char *path, const char *fmt, ...)
{
char *pathname = get_pathname();
struct strbuf buf = STRBUF_INIT;
const char *git_dir;
va_list args;
unsigned len;
len = strlen(path);
if (len > PATH_MAX-100)
return bad_path;
strbuf_addstr(&buf, path);
if (len && path[len-1] != '/')
strbuf_addch(&buf, '/');
strbuf_addstr(&buf, ".git");
git_dir = read_gitfile_gently(buf.buf);
if (git_dir) {
strbuf_reset(&buf);
strbuf_addstr(&buf, git_dir);
}
strbuf_addch(&buf, '/');
if (buf.len >= PATH_MAX)
return bad_path;
memcpy(pathname, buf.buf, buf.len + 1);
strbuf_release(&buf);
len = strlen(pathname);
va_start(args, fmt);
len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
va_end(args);
if (len >= PATH_MAX)
return bad_path;
return cleanup_path(pathname);
}
/* git_mkstemp() - create tmp file honoring TMPDIR variable */
int git_mkstemp(char *path, size_t len, const char *template)
{
const char *tmp;
size_t n;
tmp = getenv("TMPDIR");
if (!tmp)
tmp = "/tmp";
n = snprintf(path, len, "%s/%s", tmp, template);
if (len <= n) {
errno = ENAMETOOLONG;
return -1;
}
return mkstemp(path);
}
/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
{
const char *tmp;
size_t n;
tmp = getenv("TMPDIR");
if (!tmp)
tmp = "/tmp";
n = snprintf(path, len, "%s/%s", tmp, template);
if (len <= n) {
errno = ENAMETOOLONG;
return -1;
}
return mkstemps(path, suffix_len);
}
/* Adapted from libiberty's mkstemp.c. */
#undef TMP_MAX
#define TMP_MAX 16384
int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
{
static const char letters[] =
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"0123456789";
static const int num_letters = 62;
uint64_t value;
struct timeval tv;
char *template;
size_t len;
int fd, count;
len = strlen(pattern);
if (len < 6 + suffix_len) {
errno = EINVAL;
return -1;
}
if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
errno = EINVAL;
return -1;
}
/*
* Replace pattern's XXXXXX characters with randomness.
* Try TMP_MAX different filenames.
*/
gettimeofday(&tv, NULL);
value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
template = &pattern[len - 6 - suffix_len];
for (count = 0; count < TMP_MAX; ++count) {
uint64_t v = value;
/* Fill in the random bits. */
template[0] = letters[v % num_letters]; v /= num_letters;
template[1] = letters[v % num_letters]; v /= num_letters;
template[2] = letters[v % num_letters]; v /= num_letters;
template[3] = letters[v % num_letters]; v /= num_letters;
template[4] = letters[v % num_letters]; v /= num_letters;
template[5] = letters[v % num_letters]; v /= num_letters;
fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
if (fd > 0)
return fd;
/*
* Fatal error (EPERM, ENOSPC etc).
* It doesn't make sense to loop.
*/
if (errno != EEXIST)
break;
/*
* This is a random value. It is only necessary that
* the next TMP_MAX values generated by adding 7777 to
* VALUE are different with (module 2^32).
*/
value += 7777;
}
/* We return the null string if we can't find a unique file name. */
pattern[0] = '\0';
return -1;
}
int git_mkstemp_mode(char *pattern, int mode)
{
/* mkstemp is just mkstemps with no suffix */
return git_mkstemps_mode(pattern, 0, mode);
}
int gitmkstemps(char *pattern, int suffix_len)
{
return git_mkstemps_mode(pattern, suffix_len, 0600);
}
int validate_headref(const char *path)
{
struct stat st;
char *buf, buffer[256];
unsigned char sha1[20];
int fd;
ssize_t len;
if (lstat(path, &st) < 0)
return -1;
/* Make sure it is a "refs/.." symlink */
if (S_ISLNK(st.st_mode)) {
len = readlink(path, buffer, sizeof(buffer)-1);
if (len >= 5 && !memcmp("refs/", buffer, 5))
return 0;
return -1;
}
/*
* Anything else, just open it and try to see if it is a symbolic ref.
*/
fd = open(path, O_RDONLY);
if (fd < 0)
return -1;
len = read_in_full(fd, buffer, sizeof(buffer)-1);
close(fd);
/*
* Is it a symbolic ref?
*/
if (len < 4)
return -1;
if (!memcmp("ref:", buffer, 4)) {
buf = buffer + 4;
len -= 4;
while (len && isspace(*buf))
buf++, len--;
if (len >= 5 && !memcmp("refs/", buf, 5))
return 0;
}
/*
* Is this a detached HEAD?
*/
if (!get_sha1_hex(buffer, sha1))
return 0;
return -1;
}
static struct passwd *getpw_str(const char *username, size_t len)
{
struct passwd *pw;
char *username_z = xmalloc(len + 1);
memcpy(username_z, username, len);
username_z[len] = '\0';
pw = getpwnam(username_z);
free(username_z);
return pw;
}
/*
* Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
* then it is a newly allocated string. Returns NULL on getpw failure or
* if path is NULL.
*/
char *expand_user_path(const char *path)
{
struct strbuf user_path = STRBUF_INIT;
const char *first_slash = strchrnul(path, '/');
const char *to_copy = path;
if (path == NULL)
goto return_null;
if (path[0] == '~') {
const char *username = path + 1;
size_t username_len = first_slash - username;
if (username_len == 0) {
const char *home = getenv("HOME");
if (!home)
goto return_null;
strbuf_add(&user_path, home, strlen(home));
} else {
struct passwd *pw = getpw_str(username, username_len);
if (!pw)
goto return_null;
strbuf_add(&user_path, pw->pw_dir, strlen(pw->pw_dir));
}
to_copy = first_slash;
}
strbuf_add(&user_path, to_copy, strlen(to_copy));
return strbuf_detach(&user_path, NULL);
return_null:
strbuf_release(&user_path);
return NULL;
}
/*
* First, one directory to try is determined by the following algorithm.
*
* (0) If "strict" is given, the path is used as given and no DWIM is
* done. Otherwise:
* (1) "~/path" to mean path under the running user's home directory;
* (2) "~user/path" to mean path under named user's home directory;
* (3) "relative/path" to mean cwd relative directory; or
* (4) "/absolute/path" to mean absolute directory.
*
* Unless "strict" is given, we try access() for existence of "%s.git/.git",
* "%s/.git", "%s.git", "%s" in this order. The first one that exists is
* what we try.
*
* Second, we try chdir() to that. Upon failure, we return NULL.
*
* Then, we try if the current directory is a valid git repository.
* Upon failure, we return NULL.
*
* If all goes well, we return the directory we used to chdir() (but
* before ~user is expanded), avoiding getcwd() resolving symbolic
* links. User relative paths are also returned as they are given,
* except DWIM suffixing.
*/
char *enter_repo(char *path, int strict)
{
static char used_path[PATH_MAX];
static char validated_path[PATH_MAX];
if (!path)
return NULL;
if (!strict) {
static const char *suffix[] = {
".git/.git", "/.git", ".git", "", NULL,
};
int len = strlen(path);
int i;
while ((1 < len) && (path[len-1] == '/')) {
path[len-1] = 0;
len--;
}
if (PATH_MAX <= len)
return NULL;
if (path[0] == '~') {
char *newpath = expand_user_path(path);
if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
free(newpath);
return NULL;
}
/*
* Copy back into the static buffer. A pity
* since newpath was not bounded, but other
* branches of the if are limited by PATH_MAX
* anyway.
*/
strcpy(used_path, newpath); free(newpath);
strcpy(validated_path, path);
path = used_path;
}
else if (PATH_MAX - 10 < len)
return NULL;
else {
path = strcpy(used_path, path);
strcpy(validated_path, path);
}
len = strlen(path);
for (i = 0; suffix[i]; i++) {
strcpy(path + len, suffix[i]);
if (!access(path, F_OK)) {
strcat(validated_path, suffix[i]);
break;
}
}
if (!suffix[i] || chdir(path))
return NULL;
path = validated_path;
}
else if (chdir(path))
return NULL;
if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
validate_headref("HEAD") == 0) {
set_git_dir(".");
check_repository_format();
return path;
}
return NULL;
}
int set_shared_perm(const char *path, int mode)
{
struct stat st;
int tweak, shared, orig_mode;
if (!shared_repository) {
if (mode)
return chmod(path, mode & ~S_IFMT);
return 0;
}
if (!mode) {
if (lstat(path, &st) < 0)
return -1;
mode = st.st_mode;
orig_mode = mode;
} else
orig_mode = 0;
if (shared_repository < 0)
shared = -shared_repository;
else
shared = shared_repository;
tweak = shared;
if (!(mode & S_IWUSR))
tweak &= ~0222;
if (mode & S_IXUSR)
/* Copy read bits to execute bits */
tweak |= (tweak & 0444) >> 2;
if (shared_repository < 0)
mode = (mode & ~0777) | tweak;
else
mode |= tweak;
if (S_ISDIR(mode)) {
/* Copy read bits to execute bits */
mode |= (shared & 0444) >> 2;
mode |= FORCE_DIR_SET_GID;
}
if (((shared_repository < 0
? (orig_mode & (FORCE_DIR_SET_GID | 0777))
: (orig_mode & mode)) != mode) &&
chmod(path, (mode & ~S_IFMT)) < 0)
return -2;
return 0;
}
const char *make_relative_path(const char *abs, const char *base)
{
static char buf[PATH_MAX + 1];
int i = 0, j = 0;
if (!base || !base[0])
return abs;
while (base[i]) {
if (is_dir_sep(base[i])) {
if (!is_dir_sep(abs[j]))
return abs;
while (is_dir_sep(base[i]))
i++;
while (is_dir_sep(abs[j]))
j++;
continue;
} else if (abs[j] != base[i]) {
return abs;
}
i++;
j++;
}
if (
/* "/foo" is a prefix of "/foo" */
abs[j] &&
/* "/foo" is not a prefix of "/foobar" */
!is_dir_sep(base[i-1]) && !is_dir_sep(abs[j])
)
return abs;
while (is_dir_sep(abs[j]))
j++;
if (!abs[j])
strcpy(buf, ".");
else
strcpy(buf, abs + j);
return buf;
}
/*
* It is okay if dst == src, but they should not overlap otherwise.
*
* Performs the following normalizations on src, storing the result in dst:
* - Ensures that components are separated by '/' (Windows only)
* - Squashes sequences of '/'.
* - Removes "." components.
* - Removes ".." components, and the components the precede them.
* Returns failure (non-zero) if a ".." component appears as first path
* component anytime during the normalization. Otherwise, returns success (0).
*
* Note that this function is purely textual. It does not follow symlinks,
* verify the existence of the path, or make any system calls.
*/
int normalize_path_copy(char *dst, const char *src)
{
char *dst0;
if (has_dos_drive_prefix(src)) {
*dst++ = *src++;
*dst++ = *src++;
}
dst0 = dst;
if (is_dir_sep(*src)) {
*dst++ = '/';
while (is_dir_sep(*src))
src++;
}
for (;;) {
char c = *src;
/*
* A path component that begins with . could be
* special:
* (1) "." and ends -- ignore and terminate.
* (2) "./" -- ignore them, eat slash and continue.
* (3) ".." and ends -- strip one and terminate.
* (4) "../" -- strip one, eat slash and continue.
*/
if (c == '.') {
if (!src[1]) {
/* (1) */
src++;
} else if (is_dir_sep(src[1])) {
/* (2) */
src += 2;
while (is_dir_sep(*src))
src++;
continue;
} else if (src[1] == '.') {
if (!src[2]) {
/* (3) */
src += 2;
goto up_one;
} else if (is_dir_sep(src[2])) {
/* (4) */
src += 3;
while (is_dir_sep(*src))
src++;
goto up_one;
}
}
}
/* copy up to the next '/', and eat all '/' */
while ((c = *src++) != '\0' && !is_dir_sep(c))
*dst++ = c;
if (is_dir_sep(c)) {
*dst++ = '/';
while (is_dir_sep(c))
c = *src++;
src--;
} else if (!c)
break;
continue;
up_one:
/*
* dst0..dst is prefix portion, and dst[-1] is '/';
* go up one level.
*/
dst--; /* go to trailing '/' */
if (dst <= dst0)
return -1;
/* Windows: dst[-1] cannot be backslash anymore */
while (dst0 < dst && dst[-1] != '/')
dst--;
}
*dst = '\0';
return 0;
}
/*
* path = Canonical absolute path
* prefix_list = Colon-separated list of absolute paths
*
* Determines, for each path in prefix_list, whether the "prefix" really
* is an ancestor directory of path. Returns the length of the longest
* ancestor directory, excluding any trailing slashes, or -1 if no prefix
* is an ancestor. (Note that this means 0 is returned if prefix_list is
* "/".) "/foo" is not considered an ancestor of "/foobar". Directories
* are not considered to be their own ancestors. path must be in a
* canonical form: empty components, or "." or ".." components are not
* allowed. prefix_list may be null, which is like "".
*/
int longest_ancestor_length(const char *path, const char *prefix_list)
{
char buf[PATH_MAX+1];
const char *ceil, *colon;
int len, max_len = -1;
if (prefix_list == NULL || !strcmp(path, "/"))
return -1;
for (colon = ceil = prefix_list; *colon; ceil = colon+1) {
for (colon = ceil; *colon && *colon != PATH_SEP; colon++);
len = colon - ceil;
if (len == 0 || len > PATH_MAX || !is_absolute_path(ceil))
continue;
strlcpy(buf, ceil, len+1);
if (normalize_path_copy(buf, buf) < 0)
continue;
len = strlen(buf);
if (len > 0 && buf[len-1] == '/')
buf[--len] = '\0';
if (!strncmp(path, buf, len) &&
path[len] == '/' &&
len > max_len) {
max_len = len;
}
}
return max_len;
}
/* strip arbitrary amount of directory separators at end of path */
static inline int chomp_trailing_dir_sep(const char *path, int len)
{
while (len && is_dir_sep(path[len - 1]))
len--;
return len;
}
/*
* If path ends with suffix (complete path components), returns the
* part before suffix (sans trailing directory separators).
* Otherwise returns NULL.
*/
char *strip_path_suffix(const char *path, const char *suffix)
{
int path_len = strlen(path), suffix_len = strlen(suffix);
while (suffix_len) {
if (!path_len)
return NULL;
if (is_dir_sep(path[path_len - 1])) {
if (!is_dir_sep(suffix[suffix_len - 1]))
return NULL;
path_len = chomp_trailing_dir_sep(path, path_len);
suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
}
else if (path[--path_len] != suffix[--suffix_len])
return NULL;
}
if (path_len && !is_dir_sep(path[path_len - 1]))
return NULL;
return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
}
int daemon_avoid_alias(const char *p)
{
int sl, ndot;
/*
* This resurrects the belts and suspenders paranoia check by HPA
* done in <435560F7.4080006@zytor.com> thread, now enter_repo()
* does not do getcwd() based path canonicalization.
*
* sl becomes true immediately after seeing '/' and continues to
* be true as long as dots continue after that without intervening
* non-dot character.
*/
if (!p || (*p != '/' && *p != '~'))
return -1;
sl = 1; ndot = 0;
p++;
while (1) {
char ch = *p++;
if (sl) {
if (ch == '.')
ndot++;
else if (ch == '/') {
if (ndot < 3)
/* reject //, /./ and /../ */
return -1;
ndot = 0;
}
else if (ch == 0) {
if (0 < ndot && ndot < 3)
/* reject /.$ and /..$ */
return -1;
return 0;
}
else
sl = ndot = 0;
}
else if (ch == 0)
return 0;
else if (ch == '/') {
sl = 1;
ndot = 0;
}
}
}
int offset_1st_component(const char *path)
{
if (has_dos_drive_prefix(path))
return 2 + is_dir_sep(path[2]);
return is_dir_sep(path[0]);
}
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