git-instaweb: Move all actions at the end of script
[gitweb.git] / setup.c
diff --git a/setup.c b/setup.c
index 0717a98d16b8be3cb70b33b6dea7040694130a0b..ce87900ce3c68ace0f231827bdda0e9a65ef15b3 100644 (file)
--- a/setup.c
+++ b/setup.c
@@ -4,13 +4,16 @@
 static int inside_git_dir = -1;
 static int inside_work_tree = -1;
 
-const char *prefix_path(const char *prefix, int len, const char *path)
+char *prefix_path(const char *prefix, int len, const char *path)
 {
        const char *orig = path;
-       char *sanitized = xmalloc(len + strlen(path) + 1);
-       if (is_absolute_path(orig))
-               strcpy(sanitized, path);
-       else {
+       char *sanitized;
+       if (is_absolute_path(orig)) {
+               const char *temp = real_path(path);
+               sanitized = xmalloc(len + strlen(temp) + 1);
+               strcpy(sanitized, temp);
+       } else {
+               sanitized = xmalloc(len + strlen(path) + 1);
                if (len)
                        memcpy(sanitized, prefix, len);
                strcpy(sanitized + len, path);
@@ -18,14 +21,15 @@ const char *prefix_path(const char *prefix, int len, const char *path)
        if (normalize_path_copy(sanitized, sanitized))
                goto error_out;
        if (is_absolute_path(orig)) {
-               size_t len, total;
+               size_t root_len, len, total;
                const char *work_tree = get_git_work_tree();
                if (!work_tree)
                        goto error_out;
                len = strlen(work_tree);
+               root_len = offset_1st_component(work_tree);
                total = strlen(sanitized) + 1;
                if (strncmp(sanitized, work_tree, len) ||
-                   (sanitized[len] != '\0' && sanitized[len] != '/')) {
+                   (len > root_len && sanitized[len] != '\0' && sanitized[len] != '/')) {
                error_out:
                        die("'%s' is outside repository", orig);
                }
@@ -45,7 +49,7 @@ const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
 {
        static char path[PATH_MAX];
 #ifndef WIN32
-       if (!pfx || !*pfx || is_absolute_path(arg))
+       if (!pfx_len || is_absolute_path(arg))
                return arg;
        memcpy(path, pfx, pfx_len);
        strcpy(path + pfx_len, arg);
@@ -54,7 +58,7 @@ const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
        /* don't add prefix to absolute paths, but still replace '\' by '/' */
        if (is_absolute_path(arg))
                pfx_len = 0;
-       else
+       else if (pfx_len)
                memcpy(path, pfx, pfx_len);
        strcpy(path + pfx_len, arg);
        for (p = path + pfx_len; *p; p++)
@@ -81,8 +85,17 @@ static void NORETURN die_verify_filename(const char *prefix, const char *arg)
 {
        unsigned char sha1[20];
        unsigned mode;
-       /* try a detailed diagnostic ... */
-       get_sha1_with_mode_1(arg, sha1, &mode, 0, prefix);
+
+       /*
+        * Saying "'(icase)foo' does not exist in the index" when the
+        * user gave us ":(icase)foo" is just stupid.  A magic pathspec
+        * begins with a colon and is followed by a non-alnum; do not
+        * let get_sha1_with_mode_1(only_to_die=1) to even trigger.
+        */
+       if (!(arg[0] == ':' && !isalnum(arg[1])))
+               /* try a detailed diagnostic ... */
+               get_sha1_with_mode_1(arg, sha1, &mode, 1, prefix);
+
        /* ... or fall back the most general message. */
        die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
            "Use '--' to separate paths from revisions", arg);
@@ -122,6 +135,105 @@ void verify_non_filename(const char *prefix, const char *arg)
            "Use '--' to separate filenames from revisions", arg);
 }
 
+/*
+ * Magic pathspec
+ *
+ * NEEDSWORK: These need to be moved to dir.h or even to a new
+ * pathspec.h when we restructure get_pathspec() users to use the
+ * "struct pathspec" interface.
+ *
+ * Possible future magic semantics include stuff like:
+ *
+ *     { PATHSPEC_NOGLOB, '!', "noglob" },
+ *     { PATHSPEC_ICASE, '\0', "icase" },
+ *     { PATHSPEC_RECURSIVE, '*', "recursive" },
+ *     { PATHSPEC_REGEXP, '\0', "regexp" },
+ *
+ */
+#define PATHSPEC_FROMTOP    (1<<0)
+
+static struct pathspec_magic {
+       unsigned bit;
+       char mnemonic; /* this cannot be ':'! */
+       const char *name;
+} pathspec_magic[] = {
+       { PATHSPEC_FROMTOP, '/', "top" },
+};
+
+/*
+ * Take an element of a pathspec and check for magic signatures.
+ * Append the result to the prefix.
+ *
+ * For now, we only parse the syntax and throw out anything other than
+ * "top" magic.
+ *
+ * NEEDSWORK: This needs to be rewritten when we start migrating
+ * get_pathspec() users to use the "struct pathspec" interface.  For
+ * example, a pathspec element may be marked as case-insensitive, but
+ * the prefix part must always match literally, and a single stupid
+ * string cannot express such a case.
+ */
+static const char *prefix_pathspec(const char *prefix, int prefixlen, const char *elt)
+{
+       unsigned magic = 0;
+       const char *copyfrom = elt;
+       int i;
+
+       if (elt[0] != ':') {
+               ; /* nothing to do */
+       } else if (elt[1] == '(') {
+               /* longhand */
+               const char *nextat;
+               for (copyfrom = elt + 2;
+                    *copyfrom && *copyfrom != ')';
+                    copyfrom = nextat) {
+                       size_t len = strcspn(copyfrom, ",)");
+                       if (copyfrom[len] == ')')
+                               nextat = copyfrom + len;
+                       else
+                               nextat = copyfrom + len + 1;
+                       if (!len)
+                               continue;
+                       for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
+                               if (strlen(pathspec_magic[i].name) == len &&
+                                   !strncmp(pathspec_magic[i].name, copyfrom, len)) {
+                                       magic |= pathspec_magic[i].bit;
+                                       break;
+                               }
+                       if (ARRAY_SIZE(pathspec_magic) <= i)
+                               die("Invalid pathspec magic '%.*s' in '%s'",
+                                   (int) len, copyfrom, elt);
+               }
+               if (*copyfrom == ')')
+                       copyfrom++;
+       } else {
+               /* shorthand */
+               for (copyfrom = elt + 1;
+                    *copyfrom && *copyfrom != ':';
+                    copyfrom++) {
+                       char ch = *copyfrom;
+
+                       if (!is_pathspec_magic(ch))
+                               break;
+                       for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
+                               if (pathspec_magic[i].mnemonic == ch) {
+                                       magic |= pathspec_magic[i].bit;
+                                       break;
+                               }
+                       if (ARRAY_SIZE(pathspec_magic) <= i)
+                               die("Unimplemented pathspec magic '%c' in '%s'",
+                                   ch, elt);
+               }
+               if (*copyfrom == ':')
+                       copyfrom++;
+       }
+
+       if (magic & PATHSPEC_FROMTOP)
+               return xstrdup(copyfrom);
+       else
+               return prefix_path(prefix, prefixlen, copyfrom);
+}
+
 const char **get_pathspec(const char *prefix, const char **pathspec)
 {
        const char *entry = *pathspec;
@@ -143,8 +255,7 @@ const char **get_pathspec(const char *prefix, const char **pathspec)
        dst = pathspec;
        prefixlen = prefix ? strlen(prefix) : 0;
        while (*src) {
-               const char *p = prefix_path(prefix, prefixlen, *src);
-               *(dst++) = p;
+               *(dst++) = prefix_pathspec(prefix, prefixlen, *src);
                src++;
        }
        *dst = NULL;
@@ -169,6 +280,8 @@ static int is_git_directory(const char *suspect)
        char path[PATH_MAX];
        size_t len = strlen(suspect);
 
+       if (PATH_MAX <= len + strlen("/objects"))
+               die("Too long path: %.*s", 60, suspect);
        strcpy(path, suspect);
        if (getenv(DB_ENVIRONMENT)) {
                if (access(getenv(DB_ENVIRONMENT), X_OK))
@@ -205,24 +318,6 @@ int is_inside_work_tree(void)
        return inside_work_tree;
 }
 
-/*
- * set_work_tree() is only ever called if you set GIT_DIR explicitly.
- * The old behaviour (which we retain here) is to set the work tree root
- * to the cwd, unless overridden by the config, the command line, or
- * GIT_WORK_TREE.
- */
-static const char *set_work_tree(const char *dir)
-{
-       char buffer[PATH_MAX + 1];
-
-       if (!getcwd(buffer, sizeof(buffer)))
-               die ("Could not get the current working directory");
-       git_work_tree_cfg = xstrdup(buffer);
-       inside_work_tree = 1;
-
-       return NULL;
-}
-
 void setup_work_tree(void)
 {
        const char *work_tree, *git_dir;
@@ -233,16 +328,36 @@ void setup_work_tree(void)
        work_tree = get_git_work_tree();
        git_dir = get_git_dir();
        if (!is_absolute_path(git_dir))
-               git_dir = make_absolute_path(git_dir);
+               git_dir = real_path(get_git_dir());
        if (!work_tree || chdir(work_tree))
                die("This operation must be run in a work tree");
-       set_git_dir(make_relative_path(git_dir, work_tree));
+
+       /*
+        * Make sure subsequent git processes find correct worktree
+        * if $GIT_WORK_TREE is set relative
+        */
+       if (getenv(GIT_WORK_TREE_ENVIRONMENT))
+               setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
+
+       set_git_dir(relative_path(git_dir, work_tree));
        initialized = 1;
 }
 
-static int check_repository_format_gently(int *nongit_ok)
+static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 {
-       git_config(check_repository_format_version, NULL);
+       char repo_config[PATH_MAX+1];
+
+       /*
+        * git_config() can't be used here because it calls git_pathdup()
+        * to get $GIT_CONFIG/config. That call will make setup_git_env()
+        * set git_dir to ".git".
+        *
+        * We are in gitdir setup, no git dir has been found useable yet.
+        * Use a gentler version of git_config() to check if this repo
+        * is a good one.
+        */
+       snprintf(repo_config, PATH_MAX, "%s/config", gitdir);
+       git_config_early(check_repository_format_version, NULL, repo_config);
        if (GIT_REPO_VERSION < repository_format_version) {
                if (!nongit_ok)
                        die ("Expected git repo version <= %d, found %d",
@@ -267,7 +382,7 @@ const char *read_gitfile_gently(const char *path)
        const char *slash;
        struct stat st;
        int fd;
-       size_t len;
+       ssize_t len;
 
        if (stat(path, &st))
                return NULL;
@@ -304,24 +419,207 @@ const char *read_gitfile_gently(const char *path)
 
        if (!is_git_directory(dir))
                die("Not a git repository: %s", dir);
-       path = make_absolute_path(dir);
+       path = real_path(dir);
 
        free(buf);
        return path;
 }
 
+static const char *setup_explicit_git_dir(const char *gitdirenv,
+                                         char *cwd, int len,
+                                         int *nongit_ok)
+{
+       const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
+       const char *worktree;
+       char *gitfile;
+       int offset;
+
+       if (PATH_MAX - 40 < strlen(gitdirenv))
+               die("'$%s' too big", GIT_DIR_ENVIRONMENT);
+
+       gitfile = (char*)read_gitfile_gently(gitdirenv);
+       if (gitfile) {
+               gitfile = xstrdup(gitfile);
+               gitdirenv = gitfile;
+       }
+
+       if (!is_git_directory(gitdirenv)) {
+               if (nongit_ok) {
+                       *nongit_ok = 1;
+                       free(gitfile);
+                       return NULL;
+               }
+               die("Not a git repository: '%s'", gitdirenv);
+       }
+
+       if (check_repository_format_gently(gitdirenv, nongit_ok)) {
+               free(gitfile);
+               return NULL;
+       }
+
+       /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
+       if (work_tree_env)
+               set_git_work_tree(work_tree_env);
+       else if (is_bare_repository_cfg > 0) {
+               if (git_work_tree_cfg) /* #22.2, #30 */
+                       die("core.bare and core.worktree do not make sense");
+
+               /* #18, #26 */
+               set_git_dir(gitdirenv);
+               free(gitfile);
+               return NULL;
+       }
+       else if (git_work_tree_cfg) { /* #6, #14 */
+               if (is_absolute_path(git_work_tree_cfg))
+                       set_git_work_tree(git_work_tree_cfg);
+               else {
+                       char core_worktree[PATH_MAX];
+                       if (chdir(gitdirenv))
+                               die_errno("Could not chdir to '%s'", gitdirenv);
+                       if (chdir(git_work_tree_cfg))
+                               die_errno("Could not chdir to '%s'", git_work_tree_cfg);
+                       if (!getcwd(core_worktree, PATH_MAX))
+                               die_errno("Could not get directory '%s'", git_work_tree_cfg);
+                       if (chdir(cwd))
+                               die_errno("Could not come back to cwd");
+                       set_git_work_tree(core_worktree);
+               }
+       }
+       else /* #2, #10 */
+               set_git_work_tree(".");
+
+       /* set_git_work_tree() must have been called by now */
+       worktree = get_git_work_tree();
+
+       /* both get_git_work_tree() and cwd are already normalized */
+       if (!strcmp(cwd, worktree)) { /* cwd == worktree */
+               set_git_dir(gitdirenv);
+               free(gitfile);
+               return NULL;
+       }
+
+       offset = dir_inside_of(cwd, worktree);
+       if (offset >= 0) {      /* cwd inside worktree? */
+               set_git_dir(real_path(gitdirenv));
+               if (chdir(worktree))
+                       die_errno("Could not chdir to '%s'", worktree);
+               cwd[len++] = '/';
+               cwd[len] = '\0';
+               free(gitfile);
+               return cwd + offset;
+       }
+
+       /* cwd outside worktree */
+       set_git_dir(gitdirenv);
+       free(gitfile);
+       return NULL;
+}
+
+static const char *setup_discovered_git_dir(const char *gitdir,
+                                           char *cwd, int offset, int len,
+                                           int *nongit_ok)
+{
+       if (check_repository_format_gently(gitdir, nongit_ok))
+               return NULL;
+
+       /* --work-tree is set without --git-dir; use discovered one */
+       if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
+               if (offset != len && !is_absolute_path(gitdir))
+                       gitdir = xstrdup(real_path(gitdir));
+               if (chdir(cwd))
+                       die_errno("Could not come back to cwd");
+               return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
+       }
+
+       /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
+       if (is_bare_repository_cfg > 0) {
+               set_git_dir(offset == len ? gitdir : real_path(gitdir));
+               if (chdir(cwd))
+                       die_errno("Could not come back to cwd");
+               return NULL;
+       }
+
+       /* #0, #1, #5, #8, #9, #12, #13 */
+       set_git_work_tree(".");
+       if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
+               set_git_dir(gitdir);
+       inside_git_dir = 0;
+       inside_work_tree = 1;
+       if (offset == len)
+               return NULL;
+
+       /* Make "offset" point to past the '/', and add a '/' at the end */
+       offset++;
+       cwd[len++] = '/';
+       cwd[len] = 0;
+       return cwd + offset;
+}
+
+/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
+static const char *setup_bare_git_dir(char *cwd, int offset, int len, int *nongit_ok)
+{
+       int root_len;
+
+       if (check_repository_format_gently(".", nongit_ok))
+               return NULL;
+
+       /* --work-tree is set without --git-dir; use discovered one */
+       if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
+               const char *gitdir;
+
+               gitdir = offset == len ? "." : xmemdupz(cwd, offset);
+               if (chdir(cwd))
+                       die_errno("Could not come back to cwd");
+               return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
+       }
+
+       inside_git_dir = 1;
+       inside_work_tree = 0;
+       if (offset != len) {
+               if (chdir(cwd))
+                       die_errno("Cannot come back to cwd");
+               root_len = offset_1st_component(cwd);
+               cwd[offset > root_len ? offset : root_len] = '\0';
+               set_git_dir(cwd);
+       }
+       else
+               set_git_dir(".");
+       return NULL;
+}
+
+static const char *setup_nongit(const char *cwd, int *nongit_ok)
+{
+       if (!nongit_ok)
+               die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
+       if (chdir(cwd))
+               die_errno("Cannot come back to cwd");
+       *nongit_ok = 1;
+       return NULL;
+}
+
+static dev_t get_device_or_die(const char *path, const char *prefix)
+{
+       struct stat buf;
+       if (stat(path, &buf))
+               die_errno("failed to stat '%s%s%s'",
+                               prefix ? prefix : "",
+                               prefix ? "/" : "", path);
+       return buf.st_dev;
+}
+
 /*
  * We cannot decide in this function whether we are in the work tree or
  * not, since the config can only be read _after_ this function was called.
  */
-const char *setup_git_directory_gently(int *nongit_ok)
+static const char *setup_git_directory_gently_1(int *nongit_ok)
 {
-       const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
        static char cwd[PATH_MAX+1];
-       const char *gitdirenv;
-       const char *gitfile_dir;
+       const char *gitdirenv, *ret;
+       char *gitfile;
        int len, offset, ceil_offset;
+       dev_t current_device = 0;
+       int one_filesystem = 1;
 
        /*
         * Let's assume that we are in a git repository.
@@ -331,47 +629,18 @@ const char *setup_git_directory_gently(int *nongit_ok)
        if (nongit_ok)
                *nongit_ok = 0;
 
+       if (!getcwd(cwd, sizeof(cwd)-1))
+               die_errno("Unable to read current working directory");
+       offset = len = strlen(cwd);
+
        /*
         * If GIT_DIR is set explicitly, we're not going
         * to do any discovery, but we still do repository
         * validation.
         */
        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
-       if (gitdirenv) {
-               if (PATH_MAX - 40 < strlen(gitdirenv))
-                       die("'$%s' too big", GIT_DIR_ENVIRONMENT);
-               if (is_git_directory(gitdirenv)) {
-                       static char buffer[1024 + 1];
-                       const char *retval;
-
-                       if (!work_tree_env) {
-                               retval = set_work_tree(gitdirenv);
-                               /* config may override worktree */
-                               if (check_repository_format_gently(nongit_ok))
-                                       return NULL;
-                               return retval;
-                       }
-                       if (check_repository_format_gently(nongit_ok))
-                               return NULL;
-                       retval = get_relative_cwd(buffer, sizeof(buffer) - 1,
-                                       get_git_work_tree());
-                       if (!retval || !*retval)
-                               return NULL;
-                       set_git_dir(make_absolute_path(gitdirenv));
-                       if (chdir(work_tree_env) < 0)
-                               die_errno ("Could not chdir to '%s'", work_tree_env);
-                       strcat(buffer, "/");
-                       return retval;
-               }
-               if (nongit_ok) {
-                       *nongit_ok = 1;
-                       return NULL;
-               }
-               die("Not a git repository: '%s'", gitdirenv);
-       }
-
-       if (!getcwd(cwd, sizeof(cwd)-1))
-               die_errno("Unable to read current working directory");
+       if (gitdirenv)
+               return setup_explicit_git_dir(gitdirenv, cwd, len, nongit_ok);
 
        ceil_offset = longest_ancestor_length(cwd, env_ceiling_dirs);
        if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
@@ -388,56 +657,64 @@ const char *setup_git_directory_gently(int *nongit_ok)
         * - ../../.git/
         *   etc.
         */
-       offset = len = strlen(cwd);
+       one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
+       if (one_filesystem)
+               current_device = get_device_or_die(".", NULL);
        for (;;) {
-               gitfile_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
-               if (gitfile_dir) {
-                       if (set_git_dir(gitfile_dir))
-                               die("Repository setup failed");
-                       break;
+               gitfile = (char*)read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
+               if (gitfile)
+                       gitdirenv = gitfile = xstrdup(gitfile);
+               else {
+                       if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
+                               gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
                }
-               if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
-                       break;
-               if (is_git_directory(".")) {
-                       inside_git_dir = 1;
-                       if (!work_tree_env)
-                               inside_work_tree = 0;
-                       if (offset != len) {
-                               cwd[offset] = '\0';
-                               set_git_dir(cwd);
-                       } else
-                               set_git_dir(".");
-                       check_repository_format_gently(nongit_ok);
-                       return NULL;
+
+               if (gitdirenv) {
+                       ret = setup_discovered_git_dir(gitdirenv,
+                                                      cwd, offset, len,
+                                                      nongit_ok);
+                       free(gitfile);
+                       return ret;
                }
+               free(gitfile);
+
+               if (is_git_directory("."))
+                       return setup_bare_git_dir(cwd, offset, len, nongit_ok);
+
                while (--offset > ceil_offset && cwd[offset] != '/');
-               if (offset <= ceil_offset) {
-                       if (nongit_ok) {
-                               if (chdir(cwd))
-                                       die_errno("Cannot come back to cwd");
-                               *nongit_ok = 1;
-                               return NULL;
+               if (offset <= ceil_offset)
+                       return setup_nongit(cwd, nongit_ok);
+               if (one_filesystem) {
+                       dev_t parent_device = get_device_or_die("..", cwd);
+                       if (parent_device != current_device) {
+                               if (nongit_ok) {
+                                       if (chdir(cwd))
+                                               die_errno("Cannot come back to cwd");
+                                       *nongit_ok = 1;
+                                       return NULL;
+                               }
+                               cwd[offset] = '\0';
+                               die("Not a git repository (or any parent up to mount parent %s)\n"
+                               "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).", cwd);
                        }
-                       die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
                }
-               if (chdir(".."))
+               if (chdir("..")) {
+                       cwd[offset] = '\0';
                        die_errno("Cannot change to '%s/..'", cwd);
+               }
        }
+}
 
-       inside_git_dir = 0;
-       if (!work_tree_env)
-               inside_work_tree = 1;
-       git_work_tree_cfg = xstrndup(cwd, offset);
-       if (check_repository_format_gently(nongit_ok))
-               return NULL;
-       if (offset == len)
-               return NULL;
+const char *setup_git_directory_gently(int *nongit_ok)
+{
+       const char *prefix;
 
-       /* Make "offset" point to past the '/', and add a '/' at the end */
-       offset++;
-       cwd[len++] = '/';
-       cwd[len] = 0;
-       return cwd + offset;
+       prefix = setup_git_directory_gently_1(nongit_ok);
+       if (startup_info) {
+               startup_info->have_repository = !nongit_ok || !*nongit_ok;
+               startup_info->prefix = prefix;
+       }
+       return prefix;
 }
 
 int git_config_perm(const char *var, const char *value)
@@ -513,24 +790,16 @@ int check_repository_format_version(const char *var, const char *value, void *cb
 
 int check_repository_format(void)
 {
-       return check_repository_format_gently(NULL);
+       return check_repository_format_gently(get_git_dir(), NULL);
 }
 
+/*
+ * Returns the "prefix", a path to the current working directory
+ * relative to the work tree root, or NULL, if the current working
+ * directory is not a strict subdirectory of the work tree root. The
+ * prefix always ends with a '/' character.
+ */
 const char *setup_git_directory(void)
 {
-       const char *retval = setup_git_directory_gently(NULL);
-
-       /* If the work tree is not the default one, recompute prefix */
-       if (inside_work_tree < 0) {
-               static char buffer[PATH_MAX + 1];
-               char *rel;
-               if (retval && chdir(retval))
-                       die_errno ("Could not jump back into original cwd");
-               rel = get_relative_cwd(buffer, PATH_MAX, get_git_work_tree());
-               if (rel && *rel && chdir(get_git_work_tree()))
-                       die_errno ("Could not jump to working directory");
-               return rel && *rel ? strcat(rel, "/") : NULL;
-       }
-
-       return retval;
+       return setup_git_directory_gently(NULL);
 }