shared repository: optionally allow reading to "others".

This enhances core.sharedrepository to have additionally
specify that read and exec permissions to be given to others as
well.  It is useful when serving a repository via gitweb and
git-daemon that runs as a user outside the project group.

The configuration item can take the following values:

    [core]
	sharedrepository 	 ; the same as "group"
	sharedrepository = true  ; ditto
	sharedrepository = 1	 ; ditto
	sharedrepository = group ; allow rwx to group
	sharedrepository = all   ; allow rwx to group, allow rx to other
	sharedrepository = umask ; not shared - use umask

It also extends "git init-db" to take "--shared=all" and friends
from the command line.

Signed-off-by: Junio C Hamano <junkio@cox.net>

builtin-init-db.c

@@ -263,7 +263,9 @@ int cmd_init_db(int argc, const char **argv, char **envp)
 		if (!strncmp(arg, "--template=", 11))
 			template_dir = arg+11;
 		else if (!strcmp(arg, "--shared"))
-			shared_repository = 1;
+			shared_repository = PERM_GROUP;
+		else if (!strncmp(arg, "--shared=", 9))
+			shared_repository = git_config_perm("arg", arg+9);
 		else
 			die(init_db_usage);
 	}
@@ -301,8 +303,15 @@ int cmd_init_db(int argc, const char **argv, char **envp)
 	strcpy(path+len, "/info");
 	safe_create_dir(path, 1);
 
-	if (shared_repository)
-		git_config_set("core.sharedrepository", "true");
+	if (shared_repository) {
+		char buf[10];
+		/* We do not spell "group" and such, so that
+		 * the configuration can be read by older version
+		 * of git.
+		 */
+		sprintf(buf, "%d", shared_repository);
+		git_config_set("core.sharedrepository", buf);
+	}
 
 	return 0;
 }

cache.h

@@ -208,6 +208,12 @@ extern const unsigned char null_sha1[20];
 
 int git_mkstemp(char *path, size_t n, const char *template);
 
+enum sharedrepo {
+	PERM_UMASK = 0,
+	PERM_GROUP,
+	PERM_EVERYBODY
+};
+int git_config_perm(const char *var, const char *value);
 int adjust_shared_perm(const char *path);
 int safe_create_leading_directories(char *path);
 char *safe_strncpy(char *, const char *, size_t);

environment.c

@@ -18,7 +18,7 @@ int log_all_ref_updates = 0;
 int warn_ambiguous_refs = 1;
 int repository_format_version = 0;
 char git_commit_encoding[MAX_ENCODING_LENGTH] = "utf-8";
-int shared_repository = 0;
+int shared_repository = PERM_UMASK;
 const char *apply_default_whitespace = NULL;
 
 static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir,

path.c

@@ -262,11 +262,21 @@ int adjust_shared_perm(const char *path)
 		return -1;
 	mode = st.st_mode;
 	if (mode & S_IRUSR)
-		mode |= S_IRGRP;
+		mode |= (shared_repository == PERM_GROUP
+			 ? S_IRGRP
+			 : (shared_repository == PERM_EVERYBODY
+			    ? (S_IRGRP|S_IROTH)
+			    : 0));
+
 	if (mode & S_IWUSR)
 		mode |= S_IWGRP;
+
 	if (mode & S_IXUSR)
-		mode |= S_IXGRP;
+		mode |= (shared_repository == PERM_GROUP
+			 ? S_IXGRP
+			 : (shared_repository == PERM_EVERYBODY
+			    ? (S_IXGRP|S_IXOTH)
+			    : 0));
 	if (S_ISDIR(mode))
 		mode |= S_ISGID;
 	if (chmod(path, mode) < 0)

setup.c

@@ -219,12 +219,27 @@ const char *setup_git_directory_gently(int *nongit_ok)
 	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_bool(var, value);
+		shared_repository = git_config_perm(var, value);
        return 0;
 }