rebase: one safety net, one bugfix and one optimization.

diff --git a/setup.c b/setup.c
index 258da176150081749a2ca2faeebc316911f0fba1..cc44a724bf3220de1cb8a3ef818e581905d7265c 100644 (file)
--- a/setup.c
+++ b/setup.c
@@ -1,8 +1,8 @@
 #include "cache.h"
 
-char *prefix_path(const char *prefix, int len, char *path)
+const char *prefix_path(const char *prefix, int len, const char *path)
 {
-       char *orig = path;
+       const char *orig = path;
        for (;;) {
                char c;
                if (*path != '.')
@@ -47,10 +47,10 @@ char *prefix_path(const char *prefix, int len, char *path)
        return path;
 }
 
-const char **get_pathspec(const char *prefix, char **pathspec)
+const char **get_pathspec(const char *prefix, const char **pathspec)
 {
-       char *entry = *pathspec;
-       char **p;
+       const char *entry = *pathspec;
+       const char **p;
        int prefixlen;
 
        if (!prefix && !entry)
@@ -73,34 +73,62 @@ const char **get_pathspec(const char *prefix, char **pathspec)
 }
 
 /*
- * Test it it looks like we're at the top
- * level git directory. We want to see a
+ * Test if it looks like we're at the top level git directory.
+ * We want to see:
  *
- *  - a HEAD symlink and a refs/ directory under ".git"
  *  - either a .git/objects/ directory _or_ the proper
  *    GIT_OBJECT_DIRECTORY environment variable
+ *  - a refs/ directory under ".git"
+ *  - either a HEAD symlink or a HEAD file that is formatted as
+ *    a proper "ref:".
  */
 static int is_toplevel_directory(void)
 {
-       struct stat st;
-
-       return  !lstat(".git/HEAD", &st) &&
-               S_ISLNK(st.st_mode) &&
-               !access(".git/refs/", X_OK) &&
-               (gitenv(DB_ENVIRONMENT) || !access(".git/objects/", X_OK));
+       if (access(".git/refs/", X_OK) ||
+           access(getenv(DB_ENVIRONMENT) ?
+                  getenv(DB_ENVIRONMENT) : ".git/objects/", X_OK) ||
+           validate_symref(".git/HEAD"))
+               return 0;
+       return 1;
 }
 
-const char *setup_git_directory(void)
+static const char *setup_git_directory_1(void)
 {
        static char cwd[PATH_MAX+1];
        int len, offset;
 
        /*
         * If GIT_DIR is set explicitly, we're not going
-        * to do any discovery
+        * to do any discovery, but we still do repository
+        * validation.
         */
-       if (gitenv(GIT_DIR_ENVIRONMENT))
+       if (getenv(GIT_DIR_ENVIRONMENT)) {
+               char path[PATH_MAX];
+               int len = strlen(getenv(GIT_DIR_ENVIRONMENT));
+               if (sizeof(path) - 40 < len)
+                       die("'$%s' too big", GIT_DIR_ENVIRONMENT);
+               memcpy(path, getenv(GIT_DIR_ENVIRONMENT), len);
+               
+               strcpy(path + len, "/refs");
+               if (access(path, X_OK))
+                       goto bad_dir_environ;
+               strcpy(path + len, "/HEAD");
+               if (validate_symref(path))
+                       goto bad_dir_environ;
+               if (getenv(DB_ENVIRONMENT)) {
+                       if (access(DB_ENVIRONMENT, X_OK))
+                               goto bad_dir_environ;
+               }
+               else {
+                       strcpy(path + len, "/objects");
+                       if (access(path, X_OK))
+                               goto bad_dir_environ;
+               }
                return NULL;
+       bad_dir_environ:
+               path[len] = 0;
+               die("Not a git repository: '%s'", path);
+       }
 
        if (!getcwd(cwd, sizeof(cwd)) || cwd[0] != '/')
                die("Unable to read current working directory");
@@ -125,3 +153,26 @@ const char *setup_git_directory(void)
        cwd[len] = 0;
        return cwd + offset;
 }
+
+int check_repository_format_version(const char *var, const char *value)
+{
+       if (strcmp(var, "core.repositoryformatversion") == 0)
+               repository_format_version = git_config_int(var, value);
+       return 0;
+}
+
+int check_repository_format(void)
+{
+       git_config(check_repository_format_version);
+       if (GIT_REPO_VERSION < repository_format_version)
+               die ("Expected git repo version <= %d, found %d",
+                    GIT_REPO_VERSION, repository_format_version);
+       return 0;
+}
+
+const char *setup_git_directory(void)
+{
+       const char *retval = setup_git_directory_1();
+       check_repository_format();
+       return retval;
+}