lib-sieve: plugins: mailbox: tst-mailboxexists - Check mailbox name validity at runtime.

Fixes assert failure occurring at runtime (when value originates from variable).

src/lib-sieve/plugins/mailbox/tst-mailboxexists.c

@@ -157,6 +157,17 @@ tst_mailboxexists_test_mailbox(const struct sieve_runtime_env *renv,
 {
 	const struct sieve_execute_env *eenv = renv->exec_env;
 	struct mailbox *box;
+	const char *error;
+
+	/* Check validity of mailbox name */
+	if (!sieve_mailbox_check_name(mailbox, &error)) {
+		sieve_runtime_warning(
+			renv, NULL, "mailboxexists test: "
+			"invalid mailbox name `%s' specified: %s",
+			str_sanitize(mailbox, 256), error);
+		*all_exist_r = FALSE;
+		return SIEVE_EXEC_OK;
+	}
 
 	/* Open the box */
 	box = mailbox_alloc_for_user(eenv->scriptenv->user,

tests/extensions/mailbox/errors.svtest

@@ -20,4 +20,21 @@ test "Invalid Syntax" {
 	}
 }
 
+/*
+ * Mailboxexists - bad UTF-8 in mailbox name
+ */
 
+test "Mailboxexists - bad UTF-8 in mailbox name" {
+	if not test_script_compile "errors/mailboxexists-bad-utf8.sieve" {
+		test_fail "compile failed";
+	}
+
+	if not test_script_run {
+		test_fail "execution failed";
+	}
+
+	# FIXME: check warnings
+	if not test_error :count "eq" :comparator "i;ascii-numeric" "0" {
+		test_fail "wrong number of runtime errors reported";
+	}
+}

tests/extensions/mailbox/errors/mailboxexists-bad-utf8.sieve

+require "mailbox";
+require "variables";
+require "encoded-character";
+
+set "mailbox" "${hex:ff}rop";
+if mailboxexists "${mailbox}" {
+	keep;
+}
+