git-whatchanged: Add usage string

diff --git a/setup.c b/setup.c
index b8789de5c523d72110187960fb887852732f8486..d3556edf121ba78b0b83d20fdbd9cb397e79eb2b 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 +47,25 @@ char *prefix_path(const char *prefix, int len, char *path)
        return path;
 }
 
-const char **get_pathspec(const char *prefix, char **pathspec)
+/* 
+ * Unlike prefix_path, this should be used if the named file does
+ * not have to interact with index entry; i.e. name of a random file
+ * on the filesystem.
+ */
+const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
 {
-       char *entry = *pathspec;
-       char **p;
+       static char path[PATH_MAX];
+       if (!pfx || !*pfx || arg[0] == '/')
+               return arg;
+       memcpy(path, pfx, pfx_len);
+       strcpy(path + pfx_len, arg);
+       return path;
+}
+
+const char **get_pathspec(const char *prefix, const char **pathspec)
+{
+       const char *entry = *pathspec;
+       const char **p;
        int prefixlen;
 
        if (!prefix && !entry)
@@ -72,38 +87,82 @@ const char **get_pathspec(const char *prefix, char **pathspec)
        return (const char **) pathspec;
 }
 
-const char *setup_git_directory(void)
+/*
+ * Test if it looks like we're at the top level git directory.
+ * We want to see:
+ *
+ *  - 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)
+{
+       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_gently(int *nongit_ok)
 {
        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(getenv(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");
 
        offset = len = strlen(cwd);
        for (;;) {
-               /*
-                * We always want to see a .git/refs/ subdirectory
-                */
-               if (!access(".git/refs/", X_OK)) {
-                       /*
-                        * Then we need either a GIT_OBJECT_DIRECTORY define
-                        * or a .git/objects/ directory
-                        */
-                       if (gitenv(DB_ENVIRONMENT) || !access(".git/objects/", X_OK))
-                               break;
-               }
+               if (is_toplevel_directory())
+                       break;
                chdir("..");
                do {
-                       if (!offset)
+                       if (!offset) {
+                               if (nongit_ok) {
+                                       if (chdir(cwd))
+                                               die("Cannot come back to cwd");
+                                       *nongit_ok = 1;
+                                       return NULL;
+                               }
                                die("Not a git repository");
+                       }
                } while (cwd[--offset] != '/');
        }
 
@@ -116,3 +175,26 @@ 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_gently(NULL);
+       check_repository_format();
+       return retval;
+}