1 files changed, 296 insertions, 0 deletions
diff --git a/setup.c b/setup.c
new file mode 100644
index 0000000000..76e5e693cc
--- /dev/null
+++ b/setup.c
@@ -0,0 +1,296 @@
+#include "cache.h"
+
+const char *prefix_path(const char *prefix, int len, const char *path)
+{
+	const char *orig = path;
+	for (;;) {
+		char c;
+		if (*path != '.')
+			break;
+		c = path[1];
+		/* "." */
+		if (!c) {
+			path++;
+			break;
+		}
+		/* "./" */
+		if (c == '/') {
+			path += 2;
+			continue;
+		}
+		if (c != '.')
+			break;
+		c = path[2];
+		if (!c)
+			path += 2;
+		else if (c == '/')
+			path += 3;
+		else
+			break;
+		/* ".." and "../" */
+		/* Remove last component of the prefix */
+		do {
+			if (!len)
+				die("'%s' is outside repository", orig);
+			len--;
+		} while (len && prefix[len-1] != '/');
+		continue;
+	}
+	if (len) {
+		int speclen = strlen(path);
+		char *n = xmalloc(speclen + len + 1);
+	
+		memcpy(n, prefix, len);
+		memcpy(n + len, path, speclen+1);
+		path = n;
+	}
+	return path;
+}
+
+/* 
+ * 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)
+{
+	static char path[PATH_MAX];
+	if (!pfx || !*pfx || arg[0] == '/')
+		return arg;
+	memcpy(path, pfx, pfx_len);
+	strcpy(path + pfx_len, arg);
+	return path;
+}
+
+/*
+ * Verify a filename that we got as an argument for a pathspec
+ * entry. Note that a filename that begins with "-" never verifies
+ * as true, because even if such a filename were to exist, we want
+ * it to be preceded by the "--" marker (or we want the user to
+ * use a format like "./-filename")
+ */
+void verify_filename(const char *prefix, const char *arg)
+{
+	const char *name;
+	struct stat st;
+
+	if (*arg == '-')
+		die("bad flag '%s' used after filename", arg);
+	name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
+	if (!lstat(name, &st))
+		return;
+	if (errno == ENOENT)
+		die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
+		    "Use '--' to separate paths from revisions", arg);
+	die("'%s': %s", arg, strerror(errno));
+}
+
+/*
+ * Opposite of the above: the command line did not have -- marker
+ * and we parsed the arg as a refname.  It should not be interpretable
+ * as a filename.
+ */
+void verify_non_filename(const char *prefix, const char *arg)
+{
+	const char *name;
+	struct stat st;
+
+	if (is_inside_git_dir())
+		return;
+	if (*arg == '-')
+		return; /* flag */
+	name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
+	if (!lstat(name, &st))
+		die("ambiguous argument '%s': both revision and filename\n"
+		    "Use '--' to separate filenames from revisions", arg);
+	if (errno != ENOENT)
+		die("'%s': %s", arg, strerror(errno));
+}
+
+const char **get_pathspec(const char *prefix, const char **pathspec)
+{
+	const char *entry = *pathspec;
+	const char **p;
+	int prefixlen;
+
+	if (!prefix && !entry)
+		return NULL;
+
+	if (!entry) {
+		static const char *spec[2];
+		spec[0] = prefix;
+		spec[1] = NULL;
+		return spec;
+	}
+
+	/* Otherwise we have to re-write the entries.. */
+	p = pathspec;
+	prefixlen = prefix ? strlen(prefix) : 0;
+	do {
+		*p = prefix_path(prefix, prefixlen, entry);
+	} while ((entry = *++p) != NULL);
+	return (const char **) pathspec;
+}
+
+/*
+ * Test if it looks like we're at a git directory.
+ * We want to see:
+ *
+ *  - either a objects/ directory _or_ the proper
+ *    GIT_OBJECT_DIRECTORY environment variable
+ *  - a refs/ directory
+ *  - either a HEAD symlink or a HEAD file that is formatted as
+ *    a proper "ref:", or a regular file HEAD that has a properly
+ *    formatted sha1 object name.
+ */
+static int is_git_directory(const char *suspect)
+{
+	char path[PATH_MAX];
+	size_t len = strlen(suspect);
+
+	strcpy(path, suspect);
+	if (getenv(DB_ENVIRONMENT)) {
+		if (access(getenv(DB_ENVIRONMENT), X_OK))
+			return 0;
+	}
+	else {
+		strcpy(path + len, "/objects");
+		if (access(path, X_OK))
+			return 0;
+	}
+
+	strcpy(path + len, "/refs");
+	if (access(path, X_OK))
+		return 0;
+
+	strcpy(path + len, "/HEAD");
+	if (validate_headref(path))
+		return 0;
+
+	return 1;
+}
+
+static int inside_git_dir = -1;
+
+int is_inside_git_dir(void)
+{
+	if (inside_git_dir < 0) {
+		char buffer[1024];
+
+		if (is_bare_repository())
+			return (inside_git_dir = 1);
+		if (getcwd(buffer, sizeof(buffer))) {
+			const char *git_dir = get_git_dir(), *cwd = buffer;
+			while (*git_dir && *git_dir == *cwd) {
+				git_dir++;
+				cwd++;
+			}
+			inside_git_dir = !*git_dir;
+		} else
+			inside_git_dir = 0;
+	}
+	return inside_git_dir;
+}
+
+const char *setup_git_directory_gently(int *nongit_ok)
+{
+	static char cwd[PATH_MAX+1];
+	const char *gitdirenv;
+	int len, offset;
+
+	/*
+	 * 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))
+			return NULL;
+		if (nongit_ok) {
+			*nongit_ok = 1;
+			return NULL;
+		}
+		die("Not a git repository: '%s'", gitdirenv);
+	}
+
+	if (!getcwd(cwd, sizeof(cwd)-1) || cwd[0] != '/')
+		die("Unable to read current working directory");
+
+	offset = len = strlen(cwd);
+	for (;;) {
+		if (is_git_directory(".git"))
+			break;
+		chdir("..");
+		do {
+			if (!offset) {
+				if (is_git_directory(cwd)) {
+					if (chdir(cwd))
+						die("Cannot come back to cwd");
+					setenv(GIT_DIR_ENVIRONMENT, cwd, 1);
+					inside_git_dir = 1;
+					return NULL;
+				}
+				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] != '/');
+	}
+
+	if (offset == len)
+		return NULL;
+
+	/* Make "offset" point to past the '/', and add a '/' at the end */
+	offset++;
+	cwd[len++] = '/';
+	cwd[len] = 0;
+	inside_git_dir = !strncmp(cwd + offset, ".git/", 5);
+	return cwd + offset;
+}
+
+int git_config_perm(const char *var, const char *value)
+{
+	if (value) {
+		if (!strcmp(value, "umask"))
+			return PERM_UMASK;
+		if (!strcmp(value, "group"))
+			return PERM_GROUP;
+		if (!strcmp(value, "all") ||
+		    !strcmp(value, "world") ||
+		    !strcmp(value, "everybody"))
+			return PERM_EVERYBODY;
+	}
+	return git_config_bool(var, value);
+}
+
+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);
+	else if (strcmp(var, "core.sharedrepository") == 0)
+		shared_repository = git_config_perm(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;
+}