setup.con commit merge-file: handle empty files gracefully (381b851)
   1#include "cache.h"
   2#include "dir.h"
   3
   4static int inside_git_dir = -1;
   5static int inside_work_tree = -1;
   6
   7const char *prefix_path(const char *prefix, int len, const char *path)
   8{
   9        const char *orig = path;
  10        for (;;) {
  11                char c;
  12                if (*path != '.')
  13                        break;
  14                c = path[1];
  15                /* "." */
  16                if (!c) {
  17                        path++;
  18                        break;
  19                }
  20                /* "./" */
  21                if (c == '/') {
  22                        path += 2;
  23                        continue;
  24                }
  25                if (c != '.')
  26                        break;
  27                c = path[2];
  28                if (!c)
  29                        path += 2;
  30                else if (c == '/')
  31                        path += 3;
  32                else
  33                        break;
  34                /* ".." and "../" */
  35                /* Remove last component of the prefix */
  36                do {
  37                        if (!len)
  38                                die("'%s' is outside repository", orig);
  39                        len--;
  40                } while (len && prefix[len-1] != '/');
  41                continue;
  42        }
  43        if (len) {
  44                int speclen = strlen(path);
  45                char *n = xmalloc(speclen + len + 1);
  46
  47                memcpy(n, prefix, len);
  48                memcpy(n + len, path, speclen+1);
  49                path = n;
  50        }
  51        return path;
  52}
  53
  54/*
  55 * Unlike prefix_path, this should be used if the named file does
  56 * not have to interact with index entry; i.e. name of a random file
  57 * on the filesystem.
  58 */
  59const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
  60{
  61        static char path[PATH_MAX];
  62        if (!pfx || !*pfx || is_absolute_path(arg))
  63                return arg;
  64        memcpy(path, pfx, pfx_len);
  65        strcpy(path + pfx_len, arg);
  66        return path;
  67}
  68
  69/*
  70 * Verify a filename that we got as an argument for a pathspec
  71 * entry. Note that a filename that begins with "-" never verifies
  72 * as true, because even if such a filename were to exist, we want
  73 * it to be preceded by the "--" marker (or we want the user to
  74 * use a format like "./-filename")
  75 */
  76void verify_filename(const char *prefix, const char *arg)
  77{
  78        const char *name;
  79        struct stat st;
  80
  81        if (*arg == '-')
  82                die("bad flag '%s' used after filename", arg);
  83        name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
  84        if (!lstat(name, &st))
  85                return;
  86        if (errno == ENOENT)
  87                die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
  88                    "Use '--' to separate paths from revisions", arg);
  89        die("'%s': %s", arg, strerror(errno));
  90}
  91
  92/*
  93 * Opposite of the above: the command line did not have -- marker
  94 * and we parsed the arg as a refname.  It should not be interpretable
  95 * as a filename.
  96 */
  97void verify_non_filename(const char *prefix, const char *arg)
  98{
  99        const char *name;
 100        struct stat st;
 101
 102        if (!is_inside_work_tree() || is_inside_git_dir())
 103                return;
 104        if (*arg == '-')
 105                return; /* flag */
 106        name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
 107        if (!lstat(name, &st))
 108                die("ambiguous argument '%s': both revision and filename\n"
 109                    "Use '--' to separate filenames from revisions", arg);
 110        if (errno != ENOENT && errno != ENOTDIR)
 111                die("'%s': %s", arg, strerror(errno));
 112}
 113
 114const char **get_pathspec(const char *prefix, const char **pathspec)
 115{
 116        const char *entry = *pathspec;
 117        const char **p;
 118        int prefixlen;
 119
 120        if (!prefix && !entry)
 121                return NULL;
 122
 123        if (!entry) {
 124                static const char *spec[2];
 125                spec[0] = prefix;
 126                spec[1] = NULL;
 127                return spec;
 128        }
 129
 130        /* Otherwise we have to re-write the entries.. */
 131        p = pathspec;
 132        prefixlen = prefix ? strlen(prefix) : 0;
 133        do {
 134                *p = prefix_path(prefix, prefixlen, entry);
 135        } while ((entry = *++p) != NULL);
 136        return (const char **) pathspec;
 137}
 138
 139/*
 140 * Test if it looks like we're at a git directory.
 141 * We want to see:
 142 *
 143 *  - either an objects/ directory _or_ the proper
 144 *    GIT_OBJECT_DIRECTORY environment variable
 145 *  - a refs/ directory
 146 *  - either a HEAD symlink or a HEAD file that is formatted as
 147 *    a proper "ref:", or a regular file HEAD that has a properly
 148 *    formatted sha1 object name.
 149 */
 150static int is_git_directory(const char *suspect)
 151{
 152        char path[PATH_MAX];
 153        size_t len = strlen(suspect);
 154
 155        strcpy(path, suspect);
 156        if (getenv(DB_ENVIRONMENT)) {
 157                if (access(getenv(DB_ENVIRONMENT), X_OK))
 158                        return 0;
 159        }
 160        else {
 161                strcpy(path + len, "/objects");
 162                if (access(path, X_OK))
 163                        return 0;
 164        }
 165
 166        strcpy(path + len, "/refs");
 167        if (access(path, X_OK))
 168                return 0;
 169
 170        strcpy(path + len, "/HEAD");
 171        if (validate_headref(path))
 172                return 0;
 173
 174        return 1;
 175}
 176
 177int is_inside_git_dir(void)
 178{
 179        if (inside_git_dir < 0)
 180                inside_git_dir = is_inside_dir(get_git_dir());
 181        return inside_git_dir;
 182}
 183
 184int is_inside_work_tree(void)
 185{
 186        if (inside_work_tree < 0)
 187                inside_work_tree = is_inside_dir(get_git_work_tree());
 188        return inside_work_tree;
 189}
 190
 191/*
 192 * set_work_tree() is only ever called if you set GIT_DIR explicitely.
 193 * The old behaviour (which we retain here) is to set the work tree root
 194 * to the cwd, unless overridden by the config, the command line, or
 195 * GIT_WORK_TREE.
 196 */
 197static const char *set_work_tree(const char *dir)
 198{
 199        char buffer[PATH_MAX + 1];
 200
 201        if (!getcwd(buffer, sizeof(buffer)))
 202                die ("Could not get the current working directory");
 203        git_work_tree_cfg = xstrdup(buffer);
 204        inside_work_tree = 1;
 205
 206        return NULL;
 207}
 208
 209void setup_work_tree(void)
 210{
 211        const char *work_tree, *git_dir;
 212        static int initialized = 0;
 213
 214        if (initialized)
 215                return;
 216        work_tree = get_git_work_tree();
 217        git_dir = get_git_dir();
 218        if (!is_absolute_path(git_dir))
 219                set_git_dir(make_absolute_path(git_dir));
 220        if (!work_tree || chdir(work_tree))
 221                die("This operation must be run in a work tree");
 222        initialized = 1;
 223}
 224
 225static int check_repository_format_gently(int *nongit_ok)
 226{
 227        git_config(check_repository_format_version);
 228        if (GIT_REPO_VERSION < repository_format_version) {
 229                if (!nongit_ok)
 230                        die ("Expected git repo version <= %d, found %d",
 231                             GIT_REPO_VERSION, repository_format_version);
 232                warning("Expected git repo version <= %d, found %d",
 233                        GIT_REPO_VERSION, repository_format_version);
 234                warning("Please upgrade Git");
 235                *nongit_ok = -1;
 236                return -1;
 237        }
 238        return 0;
 239}
 240
 241/*
 242 * We cannot decide in this function whether we are in the work tree or
 243 * not, since the config can only be read _after_ this function was called.
 244 */
 245const char *setup_git_directory_gently(int *nongit_ok)
 246{
 247        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 248        static char cwd[PATH_MAX+1];
 249        const char *gitdirenv;
 250        int len, offset;
 251
 252        /*
 253         * If GIT_DIR is set explicitly, we're not going
 254         * to do any discovery, but we still do repository
 255         * validation.
 256         */
 257        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 258        if (gitdirenv) {
 259                if (PATH_MAX - 40 < strlen(gitdirenv))
 260                        die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 261                if (is_git_directory(gitdirenv)) {
 262                        static char buffer[1024 + 1];
 263                        const char *retval;
 264
 265                        if (!work_tree_env) {
 266                                retval = set_work_tree(gitdirenv);
 267                                /* config may override worktree */
 268                                if (check_repository_format_gently(nongit_ok))
 269                                        return NULL;
 270                                return retval;
 271                        }
 272                        if (check_repository_format_gently(nongit_ok))
 273                                return NULL;
 274                        retval = get_relative_cwd(buffer, sizeof(buffer) - 1,
 275                                        get_git_work_tree());
 276                        if (!retval || !*retval)
 277                                return NULL;
 278                        set_git_dir(make_absolute_path(gitdirenv));
 279                        if (chdir(work_tree_env) < 0)
 280                                die ("Could not chdir to %s", work_tree_env);
 281                        strcat(buffer, "/");
 282                        return retval;
 283                }
 284                if (nongit_ok) {
 285                        *nongit_ok = 1;
 286                        return NULL;
 287                }
 288                die("Not a git repository: '%s'", gitdirenv);
 289        }
 290
 291        if (!getcwd(cwd, sizeof(cwd)-1))
 292                die("Unable to read current working directory");
 293
 294        /*
 295         * Test in the following order (relative to the cwd):
 296         * - .git/
 297         * - ./ (bare)
 298         * - ../.git/
 299         * - ../ (bare)
 300         * - ../../.git/
 301         *   etc.
 302         */
 303        offset = len = strlen(cwd);
 304        for (;;) {
 305                if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 306                        break;
 307                if (is_git_directory(".")) {
 308                        inside_git_dir = 1;
 309                        if (!work_tree_env)
 310                                inside_work_tree = 0;
 311                        setenv(GIT_DIR_ENVIRONMENT, ".", 1);
 312                        check_repository_format_gently(nongit_ok);
 313                        return NULL;
 314                }
 315                chdir("..");
 316                do {
 317                        if (!offset) {
 318                                if (nongit_ok) {
 319                                        if (chdir(cwd))
 320                                                die("Cannot come back to cwd");
 321                                        *nongit_ok = 1;
 322                                        return NULL;
 323                                }
 324                                die("Not a git repository");
 325                        }
 326                } while (cwd[--offset] != '/');
 327        }
 328
 329        inside_git_dir = 0;
 330        if (!work_tree_env)
 331                inside_work_tree = 1;
 332        git_work_tree_cfg = xstrndup(cwd, offset);
 333        if (check_repository_format_gently(nongit_ok))
 334                return NULL;
 335        if (offset == len)
 336                return NULL;
 337
 338        /* Make "offset" point to past the '/', and add a '/' at the end */
 339        offset++;
 340        cwd[len++] = '/';
 341        cwd[len] = 0;
 342        return cwd + offset;
 343}
 344
 345int git_config_perm(const char *var, const char *value)
 346{
 347        if (value) {
 348                int i;
 349                if (!strcmp(value, "umask"))
 350                        return PERM_UMASK;
 351                if (!strcmp(value, "group"))
 352                        return PERM_GROUP;
 353                if (!strcmp(value, "all") ||
 354                    !strcmp(value, "world") ||
 355                    !strcmp(value, "everybody"))
 356                        return PERM_EVERYBODY;
 357                i = atoi(value);
 358                if (i > 1)
 359                        return i;
 360        }
 361        return git_config_bool(var, value);
 362}
 363
 364int check_repository_format_version(const char *var, const char *value)
 365{
 366        if (strcmp(var, "core.repositoryformatversion") == 0)
 367                repository_format_version = git_config_int(var, value);
 368        else if (strcmp(var, "core.sharedrepository") == 0)
 369                shared_repository = git_config_perm(var, value);
 370        else if (strcmp(var, "core.bare") == 0) {
 371                is_bare_repository_cfg = git_config_bool(var, value);
 372                if (is_bare_repository_cfg == 1)
 373                        inside_work_tree = -1;
 374        } else if (strcmp(var, "core.worktree") == 0) {
 375                if (!value)
 376                        return config_error_nonbool(var);
 377                if (git_work_tree_cfg)
 378                        free(git_work_tree_cfg);
 379                git_work_tree_cfg = xstrdup(value);
 380                inside_work_tree = -1;
 381        }
 382        return 0;
 383}
 384
 385int check_repository_format(void)
 386{
 387        return check_repository_format_gently(NULL);
 388}
 389
 390const char *setup_git_directory(void)
 391{
 392        const char *retval = setup_git_directory_gently(NULL);
 393
 394        /* If the work tree is not the default one, recompute prefix */
 395        if (inside_work_tree < 0) {
 396                static char buffer[PATH_MAX + 1];
 397                char *rel;
 398                if (retval && chdir(retval))
 399                        die ("Could not jump back into original cwd");
 400                rel = get_relative_cwd(buffer, PATH_MAX, get_git_work_tree());
 401                return rel && *rel ? strcat(rel, "/") : NULL;
 402        }
 403
 404        return retval;
 405}