Make git-add behave more sensibly in a case-insensitive environment
[git/git.git] / setup.c
1 #include "cache.h"
2 #include "dir.h"
3
4 static int inside_git_dir = -1;
5 static int inside_work_tree = -1;
6
7 static int sanitary_path_copy(char *dst, const char *src)
8 {
9 char *dst0 = dst;
10
11 if (*src == '/') {
12 *dst++ = '/';
13 while (*src == '/')
14 src++;
15 }
16
17 for (;;) {
18 char c = *src;
19
20 /*
21 * A path component that begins with . could be
22 * special:
23 * (1) "." and ends -- ignore and terminate.
24 * (2) "./" -- ignore them, eat slash and continue.
25 * (3) ".." and ends -- strip one and terminate.
26 * (4) "../" -- strip one, eat slash and continue.
27 */
28 if (c == '.') {
29 switch (src[1]) {
30 case '\0':
31 /* (1) */
32 src++;
33 break;
34 case '/':
35 /* (2) */
36 src += 2;
37 while (*src == '/')
38 src++;
39 continue;
40 case '.':
41 switch (src[2]) {
42 case '\0':
43 /* (3) */
44 src += 2;
45 goto up_one;
46 case '/':
47 /* (4) */
48 src += 3;
49 while (*src == '/')
50 src++;
51 goto up_one;
52 }
53 }
54 }
55
56 /* copy up to the next '/', and eat all '/' */
57 while ((c = *src++) != '\0' && c != '/')
58 *dst++ = c;
59 if (c == '/') {
60 *dst++ = c;
61 while (c == '/')
62 c = *src++;
63 src--;
64 } else if (!c)
65 break;
66 continue;
67
68 up_one:
69 /*
70 * dst0..dst is prefix portion, and dst[-1] is '/';
71 * go up one level.
72 */
73 dst -= 2; /* go past trailing '/' if any */
74 if (dst < dst0)
75 return -1;
76 while (1) {
77 if (dst <= dst0)
78 break;
79 c = *dst--;
80 if (c == '/') {
81 dst += 2;
82 break;
83 }
84 }
85 }
86 *dst = '\0';
87 return 0;
88 }
89
90 const char *prefix_path(const char *prefix, int len, const char *path)
91 {
92 const char *orig = path;
93 char *sanitized = xmalloc(len + strlen(path) + 1);
94 if (is_absolute_path(orig))
95 strcpy(sanitized, path);
96 else {
97 if (len)
98 memcpy(sanitized, prefix, len);
99 strcpy(sanitized + len, path);
100 }
101 if (sanitary_path_copy(sanitized, sanitized))
102 goto error_out;
103 if (is_absolute_path(orig)) {
104 const char *work_tree = get_git_work_tree();
105 size_t len = strlen(work_tree);
106 size_t total = strlen(sanitized) + 1;
107 if (strncmp(sanitized, work_tree, len) ||
108 (sanitized[len] != '\0' && sanitized[len] != '/')) {
109 error_out:
110 error("'%s' is outside repository", orig);
111 free(sanitized);
112 return NULL;
113 }
114 if (sanitized[len] == '/')
115 len++;
116 memmove(sanitized, sanitized + len, total - len);
117 }
118 return sanitized;
119 }
120
121 /*
122 * Unlike prefix_path, this should be used if the named file does
123 * not have to interact with index entry; i.e. name of a random file
124 * on the filesystem.
125 */
126 const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
127 {
128 static char path[PATH_MAX];
129 if (!pfx || !*pfx || is_absolute_path(arg))
130 return arg;
131 memcpy(path, pfx, pfx_len);
132 strcpy(path + pfx_len, arg);
133 return path;
134 }
135
136 /*
137 * Verify a filename that we got as an argument for a pathspec
138 * entry. Note that a filename that begins with "-" never verifies
139 * as true, because even if such a filename were to exist, we want
140 * it to be preceded by the "--" marker (or we want the user to
141 * use a format like "./-filename")
142 */
143 void verify_filename(const char *prefix, const char *arg)
144 {
145 const char *name;
146 struct stat st;
147
148 if (*arg == '-')
149 die("bad flag '%s' used after filename", arg);
150 name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
151 if (!lstat(name, &st))
152 return;
153 if (errno == ENOENT)
154 die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
155 "Use '--' to separate paths from revisions", arg);
156 die("'%s': %s", arg, strerror(errno));
157 }
158
159 /*
160 * Opposite of the above: the command line did not have -- marker
161 * and we parsed the arg as a refname. It should not be interpretable
162 * as a filename.
163 */
164 void verify_non_filename(const char *prefix, const char *arg)
165 {
166 const char *name;
167 struct stat st;
168
169 if (!is_inside_work_tree() || is_inside_git_dir())
170 return;
171 if (*arg == '-')
172 return; /* flag */
173 name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
174 if (!lstat(name, &st))
175 die("ambiguous argument '%s': both revision and filename\n"
176 "Use '--' to separate filenames from revisions", arg);
177 if (errno != ENOENT && errno != ENOTDIR)
178 die("'%s': %s", arg, strerror(errno));
179 }
180
181 const char **get_pathspec(const char *prefix, const char **pathspec)
182 {
183 const char *entry = *pathspec;
184 const char **src, **dst;
185 int prefixlen;
186
187 if (!prefix && !entry)
188 return NULL;
189
190 if (!entry) {
191 static const char *spec[2];
192 spec[0] = prefix;
193 spec[1] = NULL;
194 return spec;
195 }
196
197 /* Otherwise we have to re-write the entries.. */
198 src = pathspec;
199 dst = pathspec;
200 prefixlen = prefix ? strlen(prefix) : 0;
201 while (*src) {
202 const char *p = prefix_path(prefix, prefixlen, *src);
203 if (p)
204 *(dst++) = p;
205 else
206 exit(128); /* error message already given */
207 src++;
208 }
209 *dst = NULL;
210 if (!*pathspec)
211 return NULL;
212 return pathspec;
213 }
214
215 /*
216 * Test if it looks like we're at a git directory.
217 * We want to see:
218 *
219 * - either an objects/ directory _or_ the proper
220 * GIT_OBJECT_DIRECTORY environment variable
221 * - a refs/ directory
222 * - either a HEAD symlink or a HEAD file that is formatted as
223 * a proper "ref:", or a regular file HEAD that has a properly
224 * formatted sha1 object name.
225 */
226 static int is_git_directory(const char *suspect)
227 {
228 char path[PATH_MAX];
229 size_t len = strlen(suspect);
230
231 strcpy(path, suspect);
232 if (getenv(DB_ENVIRONMENT)) {
233 if (access(getenv(DB_ENVIRONMENT), X_OK))
234 return 0;
235 }
236 else {
237 strcpy(path + len, "/objects");
238 if (access(path, X_OK))
239 return 0;
240 }
241
242 strcpy(path + len, "/refs");
243 if (access(path, X_OK))
244 return 0;
245
246 strcpy(path + len, "/HEAD");
247 if (validate_headref(path))
248 return 0;
249
250 return 1;
251 }
252
253 int is_inside_git_dir(void)
254 {
255 if (inside_git_dir < 0)
256 inside_git_dir = is_inside_dir(get_git_dir());
257 return inside_git_dir;
258 }
259
260 int is_inside_work_tree(void)
261 {
262 if (inside_work_tree < 0)
263 inside_work_tree = is_inside_dir(get_git_work_tree());
264 return inside_work_tree;
265 }
266
267 /*
268 * set_work_tree() is only ever called if you set GIT_DIR explicitely.
269 * The old behaviour (which we retain here) is to set the work tree root
270 * to the cwd, unless overridden by the config, the command line, or
271 * GIT_WORK_TREE.
272 */
273 static const char *set_work_tree(const char *dir)
274 {
275 char buffer[PATH_MAX + 1];
276
277 if (!getcwd(buffer, sizeof(buffer)))
278 die ("Could not get the current working directory");
279 git_work_tree_cfg = xstrdup(buffer);
280 inside_work_tree = 1;
281
282 return NULL;
283 }
284
285 void setup_work_tree(void)
286 {
287 const char *work_tree, *git_dir;
288 static int initialized = 0;
289
290 if (initialized)
291 return;
292 work_tree = get_git_work_tree();
293 git_dir = get_git_dir();
294 if (!is_absolute_path(git_dir))
295 set_git_dir(make_absolute_path(git_dir));
296 if (!work_tree || chdir(work_tree))
297 die("This operation must be run in a work tree");
298 initialized = 1;
299 }
300
301 static int check_repository_format_gently(int *nongit_ok)
302 {
303 git_config(check_repository_format_version);
304 if (GIT_REPO_VERSION < repository_format_version) {
305 if (!nongit_ok)
306 die ("Expected git repo version <= %d, found %d",
307 GIT_REPO_VERSION, repository_format_version);
308 warning("Expected git repo version <= %d, found %d",
309 GIT_REPO_VERSION, repository_format_version);
310 warning("Please upgrade Git");
311 *nongit_ok = -1;
312 return -1;
313 }
314 return 0;
315 }
316
317 /*
318 * We cannot decide in this function whether we are in the work tree or
319 * not, since the config can only be read _after_ this function was called.
320 */
321 const char *setup_git_directory_gently(int *nongit_ok)
322 {
323 const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
324 static char cwd[PATH_MAX+1];
325 const char *gitdirenv;
326 int len, offset;
327
328 /*
329 * Let's assume that we are in a git repository.
330 * If it turns out later that we are somewhere else, the value will be
331 * updated accordingly.
332 */
333 if (nongit_ok)
334 *nongit_ok = 0;
335
336 /*
337 * If GIT_DIR is set explicitly, we're not going
338 * to do any discovery, but we still do repository
339 * validation.
340 */
341 gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
342 if (gitdirenv) {
343 if (PATH_MAX - 40 < strlen(gitdirenv))
344 die("'$%s' too big", GIT_DIR_ENVIRONMENT);
345 if (is_git_directory(gitdirenv)) {
346 static char buffer[1024 + 1];
347 const char *retval;
348
349 if (!work_tree_env) {
350 retval = set_work_tree(gitdirenv);
351 /* config may override worktree */
352 if (check_repository_format_gently(nongit_ok))
353 return NULL;
354 return retval;
355 }
356 if (check_repository_format_gently(nongit_ok))
357 return NULL;
358 retval = get_relative_cwd(buffer, sizeof(buffer) - 1,
359 get_git_work_tree());
360 if (!retval || !*retval)
361 return NULL;
362 set_git_dir(make_absolute_path(gitdirenv));
363 if (chdir(work_tree_env) < 0)
364 die ("Could not chdir to %s", work_tree_env);
365 strcat(buffer, "/");
366 return retval;
367 }
368 if (nongit_ok) {
369 *nongit_ok = 1;
370 return NULL;
371 }
372 die("Not a git repository: '%s'", gitdirenv);
373 }
374
375 if (!getcwd(cwd, sizeof(cwd)-1))
376 die("Unable to read current working directory");
377
378 /*
379 * Test in the following order (relative to the cwd):
380 * - .git/
381 * - ./ (bare)
382 * - ../.git/
383 * - ../ (bare)
384 * - ../../.git/
385 * etc.
386 */
387 offset = len = strlen(cwd);
388 for (;;) {
389 if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
390 break;
391 if (is_git_directory(".")) {
392 inside_git_dir = 1;
393 if (!work_tree_env)
394 inside_work_tree = 0;
395 setenv(GIT_DIR_ENVIRONMENT, ".", 1);
396 check_repository_format_gently(nongit_ok);
397 return NULL;
398 }
399 chdir("..");
400 do {
401 if (!offset) {
402 if (nongit_ok) {
403 if (chdir(cwd))
404 die("Cannot come back to cwd");
405 *nongit_ok = 1;
406 return NULL;
407 }
408 die("Not a git repository");
409 }
410 } while (cwd[--offset] != '/');
411 }
412
413 inside_git_dir = 0;
414 if (!work_tree_env)
415 inside_work_tree = 1;
416 git_work_tree_cfg = xstrndup(cwd, offset);
417 if (check_repository_format_gently(nongit_ok))
418 return NULL;
419 if (offset == len)
420 return NULL;
421
422 /* Make "offset" point to past the '/', and add a '/' at the end */
423 offset++;
424 cwd[len++] = '/';
425 cwd[len] = 0;
426 return cwd + offset;
427 }
428
429 int git_config_perm(const char *var, const char *value)
430 {
431 if (value) {
432 int i;
433 if (!strcmp(value, "umask"))
434 return PERM_UMASK;
435 if (!strcmp(value, "group"))
436 return PERM_GROUP;
437 if (!strcmp(value, "all") ||
438 !strcmp(value, "world") ||
439 !strcmp(value, "everybody"))
440 return PERM_EVERYBODY;
441 i = atoi(value);
442 if (i > 1)
443 return i;
444 }
445 return git_config_bool(var, value);
446 }
447
448 int check_repository_format_version(const char *var, const char *value)
449 {
450 if (strcmp(var, "core.repositoryformatversion") == 0)
451 repository_format_version = git_config_int(var, value);
452 else if (strcmp(var, "core.sharedrepository") == 0)
453 shared_repository = git_config_perm(var, value);
454 else if (strcmp(var, "core.bare") == 0) {
455 is_bare_repository_cfg = git_config_bool(var, value);
456 if (is_bare_repository_cfg == 1)
457 inside_work_tree = -1;
458 } else if (strcmp(var, "core.worktree") == 0) {
459 if (!value)
460 return config_error_nonbool(var);
461 free(git_work_tree_cfg);
462 git_work_tree_cfg = xstrdup(value);
463 inside_work_tree = -1;
464 }
465 return 0;
466 }
467
468 int check_repository_format(void)
469 {
470 return check_repository_format_gently(NULL);
471 }
472
473 const char *setup_git_directory(void)
474 {
475 const char *retval = setup_git_directory_gently(NULL);
476
477 /* If the work tree is not the default one, recompute prefix */
478 if (inside_work_tree < 0) {
479 static char buffer[PATH_MAX + 1];
480 char *rel;
481 if (retval && chdir(retval))
482 die ("Could not jump back into original cwd");
483 rel = get_relative_cwd(buffer, PATH_MAX, get_git_work_tree());
484 return rel && *rel ? strcat(rel, "/") : NULL;
485 }
486
487 return retval;
488 }