Fix query-size reset and negative value validation

Author: SamNet-dev

cmd/scan.go

@@ -90,10 +90,11 @@ func runScan(cmd *cobra.Command, args []string) error {
 	querySize, _ := cmd.Flags().GetInt("query-size")
 	cidrRanges, _ := cmd.Flags().GetStringSlice("cidr")
 
-	// Apply query size (dnstt-client MTU)
-	if querySize > 0 {
-		scanner.DnsttMTU = querySize
+	// Apply query size (dnstt-client MTU); 0 = use max
+	if querySize < 0 {
+		return fmt.Errorf("--query-size must be >= 0 (got %d)", querySize)
 	}
+	scanner.DnsttMTU = querySize
 
 	// Apply EDNS buffer size
 	if ednsSize > 0 && ednsSize <= 65535 {

internal/tui/screen_welcome.go

@@ -153,8 +153,12 @@ func parseCLIFlags(m *Model, raw string) {
 			}
 		case "--query-size":
 			if next != "" {
-				fmt.Sscanf(next, "%d", &m.config.QuerySize)
-				m.configInputs[txtQuerySize].SetValue(next)
+				var qs int
+				fmt.Sscanf(next, "%d", &qs)
+				if qs >= 0 {
+					m.config.QuerySize = qs
+					m.configInputs[txtQuerySize].SetValue(next)
+				}
 				i++
 			}
 		case "--e2e":