# HG changeset patch
# User Kim Alvefur <zash@zash.se>
# Date 1746455565 -7200
# Node ID 9eee04a95a253688db3109f461ab5eb6b1e5473c
# Parent  8078eebf5601989e5f87f408e36a0087fedc96d4
MUC: Fix nickname registration form error handling (fixes #1930)

`dataform:data()` always returns the first table of collected values,
even if there are errors, so checking for its absence did not detect
when a required field (the only field, nickname) was missing.

diff -r 8078eebf5601 -r 9eee04a95a25 plugins/muc/register.lib.lua
--- a/plugins/muc/register.lib.lua	Mon May 05 15:05:53 2025 +0200
+++ b/plugins/muc/register.lib.lua	Mon May 05 16:32:45 2025 +0200
@@ -172,9 +172,13 @@
 			origin.send(st.error_reply(stanza, "modify", "bad-request", "Error in form"));
 			return true;
 		end
-		local reg_data = registration_form:data(form_tag);
-		if not reg_data then
-			origin.send(st.error_reply(stanza, "modify", "bad-request", "Error in form"));
+		local reg_data, form_err = registration_form:data(form_tag);
+		if form_err then
+			local errs = {};
+			for field, err in pairs(form_err) do
+				table.insert(errs, field..": "..err);
+			end
+			origin.send(st.error_reply(stanza, "modify", "bad-request", "Error in form: "..table.concat(errs)));
 			return true;
 		end
 		-- Is the nickname valid?