fix(haproxyctl): Prevent config corruption from nested config_foreach

Pre-collect server sections to temp file before iterating backends to avoid
UCI state corruption. Nested config_foreach calls were causing server lines
to appear in wrong sections (userlist, global).

Changes:
- Add _precollect_server() to gather all server data before backend iteration
- Store server data as pipe-delimited records in temp file
- Replace _check_server_sections nested iteration with grep lookup
- Replace _add_server_to_backend nested iteration with grep + while read
- Mark old _add_server_to_backend as DEPRECATED

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package/secubox/secubox-app-haproxy/files/usr/sbin/haproxyctl

@@ -951,12 +951,56 @@ backend acme_challenge
 
 EOF
 
+	# PRE-COLLECT ALL SERVER SECTIONS TO AVOID NESTED config_foreach
+	# This prevents UCI state corruption during backend iteration
+	# Bug fix: nested config_foreach calls were interleaving output
+	_servers_data="/tmp/haproxy_servers.$$"
+	rm -f "$_servers_data"
+
+	_precollect_server() {
+		local section="$1"
+		local backend server_name address port weight check enabled
+		config_get backend "$section" backend
+		config_get enabled "$section" enabled "0"
+		[ "$enabled" = "1" ] || return
+		[ -n "$backend" ] || return
+
+		config_get server_name "$section" name "$section"
+		config_get address "$section" address
+		config_get port "$section" port "80"
+		config_get weight "$section" weight "100"
+		config_get check "$section" check "1"
+
+		[ -n "$address" ] || return
+
+		# Resolve hostname to IP if needed
+		if ! echo "$address" | grep -qE '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$'; then
+			local resolved_ip=""
+			resolved_ip=$(nslookup "$address" 2>/dev/null | awk '/^Address: / { print $2; exit }')
+			if [ -z "$resolved_ip" ]; then
+				resolved_ip=$(getent hosts "$address" 2>/dev/null | awk '{print $1; exit}')
+			fi
+			if [ -z "$resolved_ip" ]; then
+				log_warn "Cannot resolve hostname '$address' for server $server_name in backend $backend - skipping"
+				return
+			fi
+			address="$resolved_ip"
+		fi
+
+		# Store in temp file: backend|server_name|address|port|weight|check
+		echo "${backend}|${server_name}|${address}|${port}|${weight}|${check}" >> "$_servers_data"
+	}
+	config_foreach _precollect_server server
+
 	# Track which backends are generated
 	_generated_backends=""
 
-	# Generate each backend from UCI
+	# Generate each backend from UCI (now safe - no nested config_foreach needed)
 	config_foreach _generate_backend backend
 
+	# Cleanup server data temp file
+	rm -f "$_servers_data"
+
 	# Collect all backends referenced by vhosts
 	_referenced_backends=""
 	_collect_vhost_backend() {
@@ -1039,17 +1083,12 @@ _generate_backend() {
 	fi
 
 	# Check if there are separate server sections for this backend
+	# NOW USES PRE-COLLECTED DATA instead of nested config_foreach
+	# This avoids UCI state corruption that caused server lines in wrong sections
 	local has_server_sections=0
-	_check_server_sections() {
-		local srv_section="$1"
-		local srv_backend
-		config_get srv_backend "$srv_section" backend
-		config_get srv_enabled "$srv_section" enabled "0"
-		if [ "$srv_backend" = "$name" ] && [ "$srv_enabled" = "1" ]; then
-			has_server_sections=1
-		fi
-	}
-	config_foreach _check_server_sections server
+	if [ -f "$_servers_data" ] && grep -q "^${name}|" "$_servers_data"; then
+		has_server_sections=1
+	fi
 
 	# Add inline server ONLY if no separate server sections exist
 	# This prevents duplicate server names
@@ -1059,11 +1098,20 @@ _generate_backend() {
 		[ -n "$server_line" ] && echo "    server $server_line"
 	fi
 
-	# Add servers from separate server UCI sections
-	config_foreach _add_server_to_backend server "$name"
+	# Add servers from pre-collected data (avoiding nested config_foreach)
+	if [ -f "$_servers_data" ]; then
+		grep "^${name}|" "$_servers_data" 2>/dev/null | while IFS='|' read -r _backend srv_name srv_addr srv_port srv_weight srv_check; do
+			local check_opt=""
+			[ "$srv_check" = "1" ] && check_opt="check"
+			echo "    server $srv_name $srv_addr:$srv_port weight $srv_weight $check_opt"
+		done
+	fi
 }
 
-_add_server_to_backend() {
+# DEPRECATED: This function is no longer used - server data is now pre-collected
+# in _generate_backends() to avoid nested config_foreach bugs.
+# Kept for reference only.
+_add_server_to_backend_DEPRECATED() {
 	local section="$1"
 	local target_backend="$2"
 	local backend server_name address port weight check enabled