doveadm: Fix printing help for sub-sub-commands

For example "doveadm mailbox" would list all mailbox commands, but
"doveadm mailbox metadata" still listed just mailbox commands, not
"mailbox metadata commands".

diff --git a/src/doveadm/doveadm.c b/src/doveadm/doveadm.c
index b11cef1cd47b2a38316988973f81932f4eba872a..1f0743ae09e6127f9ddc3f72c076a562ce7a33f7 100644 (file)
--- a/src/doveadm/doveadm.c
+++ b/src/doveadm/doveadm.c
@@ -252,6 +252,25 @@ static bool doveadm_has_subcommands(const char *cmd_name)
        return FALSE;
 }
 
+static const char *
+find_longest_cmd_prefix(char *const argv[])
+{
+       string_t *prefix = t_str_new(128);
+       str_append(prefix, argv[0]);
+
+       size_t last_len = str_len(prefix);
+       unsigned int i = 1;
+       while (doveadm_has_subcommands(str_c(prefix))) {
+               last_len = str_len(prefix);
+               if (argv[i] == NULL)
+                       break;
+               str_append_c(prefix, ' ');
+               str_append(prefix, argv[i++]);
+       }
+       str_truncate(prefix, last_len);
+       return str_c(prefix);
+}
+
 static struct doveadm_cmd_ver2 *doveadm_cmdline_commands_ver2[] = {
        &doveadm_cmd_config,
        &doveadm_cmd_dump,
@@ -390,9 +409,12 @@ int main(int argc, char *argv[])
                if (cctx->help_requested == DOVEADM_CMD_VER2_HELP_ARGUMENT &&
                    cctx->cmd != NULL) {
                        print_usage_and_exit(stdout, cctx->cmd, EX_OK);
+               } else {
+                       const char *cmd_prefix =
+                               find_longest_cmd_prefix(argv);
+                       if (doveadm_has_subcommands(cmd_prefix))
+                               usage_prefix(out, cmd_prefix, exit_code);
                }
-               if (doveadm_has_subcommands(cmd_name))
-                       usage_prefix(out, cmd_name, exit_code);
 
                if (doveadm_has_unloaded_plugin(cmd_name)) {
                        i_fatal("Unknown command '%s', but plugin %s exists. "