feat: warn about the server's forward limit and an auto-reply too long for it (bulwarkmail/webmail#1155, bulwarkmail/webmail#1208)

src/components/filters/FilterRuleModal.tsx

@@ -42,6 +42,8 @@ import type {
   FilterActionType,
 } from '../../lib/sieve/types';
 import { SafeAreaModal } from '../SafeAreaModal';
+import { useFilterStore } from '../../stores/filter-store';
+import { forwardsOfEditedRule, ruleForwardLimit } from '../../lib/sieve/forward-limit';
 import { MODAL_ORIENTATIONS } from '../../lib/modal-orientations';
 
 const ALL_FIELDS: FilterConditionField[] = ['from', 'to', 'cc', 'subject', 'header', 'size', 'body', 'attachment', 'all'];
@@ -72,12 +74,19 @@ interface FilterRuleModalProps {
   mailboxes: Mailbox[];
   /** The server can confine a rule to a period (Sieve "date" and "relational"). */
   periodsSupported?: boolean;
+  /**
+   * The server's cap on forwards per message, and the forwards a message can
+   * have collected when it reaches this rule / still collect below it (see
+   * lib/sieve/forward-limit.ts). Left out: read from the filter list the
+   * Filters settings show.
+   */
+  forwardContext?: { maxRedirects: number | null | undefined; before: number; after: number };
   onSave: (rule: FilterRule) => void;
   onClose: () => void;
 }
 
 export function FilterRuleModal({
-  visible, rule: editedRule, initialRule, mailboxes, periodsSupported = false, onSave, onClose,
+  visible, rule: editedRule, initialRule, mailboxes, periodsSupported = false, forwardContext, onSave, onClose,
 }: FilterRuleModalProps) {
   const c = useColors();
   const styles = useMemo(() => makeStyles(c), [c]);
@@ -120,6 +129,25 @@ export function FilterRuleModal({
 
   const mailboxTargets = useMemo(() => buildMailboxTargets(mailboxes), [mailboxes]);
 
+  // A message can collect only so many forwards on the server (#1155, #1208).
+  const listedRules = useFilterStore((s) => s.rules);
+  const listedForward = useFilterStore((s) => s.vacationForward);
+  const listedMaxRedirects = useFilterStore((s) => s.sieveCapabilities?.maxNumberRedirects);
+  const listedAround = useMemo(
+    () => forwardsOfEditedRule(listedRules, listedForward, editedRule?.id),
+    [listedRules, listedForward, editedRule?.id],
+  );
+  const forwardLimit = ruleForwardLimit(
+    { actions, stopProcessing },
+    forwardContext ? forwardContext.maxRedirects : listedMaxRedirects,
+    forwardContext ?? listedAround,
+  );
+  const ruleForwardCount = actions.filter((a) => a.type === 'forward').length;
+  const actionOptionsFor = (action: FilterAction) =>
+    action.type === 'forward' || forwardLimit.canAddForward
+      ? actionTypeOptions
+      : actionTypeOptions.filter((o) => o.value !== 'forward');
+
   const fieldOptions = useMemo(
     () => ALL_FIELDS.map((f) => ({ value: f, label: t(`settings.filters.condition_fields.${f}`, f) })),
     [t],
@@ -407,7 +435,7 @@ export function FilterRuleModal({
                       <Select
                         value={action.type}
                         onChange={(v) => updateAction(index, { type: v as FilterActionType })}
-                        options={actionTypeOptions}
+                        options={actionOptionsFor(action)}
                         style={{ flex: 1 }}
                       />
                       <Pressable
@@ -489,6 +517,16 @@ export function FilterRuleModal({
                   </View>
                 ))}
               </View>
+              {forwardLimit.unavailable && ruleForwardCount > 0 && (
+                <Text style={styles.forwardWarning}>
+                  {t('settings.filters.forward_unavailable', 'This server does not allow forwarding. Forward actions in filter rules have no effect.')}
+                </Text>
+              )}
+              {forwardLimit.overLimit && (
+                <Text style={styles.forwardWarning}>
+                  {t('settings.filters.forward_limit', 'Forward limit per message on this server: {count}. Extra forwards are skipped.', { count: forwardLimit.limit ?? 0 })}
+                </Text>
+              )}
               <Pressable
                 onPress={() => setActions((prev) => [...prev, makeEmptyAction()])}
                 style={styles.addRow}
@@ -645,6 +683,7 @@ function makeStyles(c: ThemePalette) {
     },
     optionLabel: { ...typography.body, color: c.text, flex: 1 },
     hint: { ...typography.caption, color: c.mutedForeground },
+    forwardWarning: { ...typography.caption, color: c.warning, marginTop: spacing.sm },
 
     footer: {
       flexDirection: 'row',

src/components/filters/QuickRuleSheet.tsx

@@ -5,7 +5,8 @@ import { MoveSheet } from '../MoveSheet';
 import { FilterRuleModal } from './FilterRuleModal';
 import type { Email, Mailbox } from '../../api/types';
 import { getSieveAccountId, getSieveCapabilities } from '../../api/sieve';
-import { FiltersLoginChangedError, OpaqueFiltersError, updateAccountFilters } from '../../api/sieve-rules';
+import { FiltersLoginChangedError, OpaqueFiltersError, readAccountFilters, updateAccountFilters } from '../../api/sieve-rules';
+import { forwardsAround, inRunOrder } from '../../lib/sieve/forward-limit';
 import { jmapClient } from '../../api/jmap-client';
 import { servedLoginOf } from '../../lib/draft-login';
 import { supportsPeriods } from '../../lib/sieve/period';
@@ -87,6 +88,26 @@ export function QuickRuleSheet({ visible, email, mailboxes, onClose }: QuickRule
   const junk = React.useMemo(() => findJunkMailbox(mailboxes), [mailboxes]);
   const periodsSupported = supportsPeriods(getSieveCapabilities()?.sieveExtensions);
 
+  // Where the new rule runs among the account's rules, for the server's
+  // redirect limit: at the top, behind the out of office forwarding
+  // (webmail quick-rule-host.tsx; lib/sieve/forward-limit.ts).
+  const editorOpen = visible && step.kind === 'editor';
+  const [forwards, setForwards] = React.useState({ before: 0, after: 0 });
+  React.useEffect(() => {
+    setForwards({ before: 0, after: 0 });
+    if (!editorOpen) return;
+    let current = true;
+    const accountId = openedIn.current.accountId ?? undefined;
+    readAccountFilters(accountId)
+      .then((parsed) => {
+        if (!current || parsed.isOpaque) return;
+        const runOrder = inRunOrder(parsed.rules, parsed.vacationForward);
+        setForwards(forwardsAround(runOrder, runOrder.length - parsed.rules.length, false));
+      })
+      .catch(() => undefined);
+    return () => { current = false; };
+  }, [editorOpen]);
+
   const [sender] = subject.senders;
   const senderLabel = subject.senders.length === 1
     ? (sender.name || sender.email)
@@ -248,6 +269,10 @@ export function QuickRuleSheet({ visible, email, mailboxes, onClose }: QuickRule
         initialRule={step.kind === 'editor' ? step.rule : undefined}
         mailboxes={mailboxes}
         periodsSupported={periodsSupported}
+        forwardContext={{
+          maxRedirects: getSieveCapabilities(openedIn.current.accountId ?? undefined)?.maxNumberRedirects,
+          ...forwards,
+        }}
         onSave={(rule) => void saveEditorRule(rule)}
         onClose={finish}
       />

src/components/settings/VacationSettings.tsx

@@ -26,6 +26,9 @@ import {
   parseLocalInput,
   utcIsoToLocalInput,
 } from '../../lib/vacation-dates';
+import { STALWART_VACATION_LIMITS, vacationOversize } from '../../lib/vacation-limits';
+import { jmapClient } from '../../api/jmap-client';
+import { getSieveCapabilities } from '../../api/sieve';
 
 // Ported from the webmail's components/settings/vacation-settings.tsx. Dates
 // are typed as local wall-clock time and sent as RFC 8621 UTCDate strings;
@@ -122,6 +125,11 @@ export function VacationSettings() {
   // Only what was changed here is sent: the rest stays as the server has it,
   // which another device may have changed since this one loaded.
   const forwardChanged = forwardSettings !== undefined && !sameForward(forwardSettings, store.forward);
+  // Kept here, the message goes on through the filter rules, whose forwards
+  // share the server's limit with this one (#1208).
+  const forwardLimit = getSieveCapabilities(managedAccountId ?? undefined)?.maxNumberRedirects;
+  const forwardOverLimit = store.forwardAvailable && forwardEnabled && forwardKeep
+    && typeof forwardLimit === 'number' && forwardLimit > 0 && 1 + store.otherForwards > forwardLimit;
 
   const fromParsed = parseLocalInput(fromDate);
   const toParsed = parseLocalInput(toDate);
@@ -137,6 +145,22 @@ export function VacationSettings() {
     return fromParsed < todayStart;
   }, [fromParsed]);
 
+  // What a save sends, measured against the server's limits as you type.
+  const sizeLimits = jmapClient.hasAccountCapability('urn:stalwart:jmap', managedAccountId ?? undefined)
+    ? STALWART_VACATION_LIMITS
+    : null;
+  const oversize = useMemo(() => {
+    const sanitizedHtml = hasHtmlContent ? stripDangerousTags(htmlBody) : null;
+    const textBody = body.trim() || !sanitizedHtml ? body : htmlToPlainText(sanitizedHtml);
+    return vacationOversize({ subject: subject.trim(), textBody, htmlBody: sanitizedHtml }, sizeLimits);
+  }, [hasHtmlContent, htmlBody, body, subject, sizeLimits]);
+  const subjectTooLong = oversize.subject && sizeLimits
+    ? t('settings.vacation.warnings.subject_too_long', 'The subject is too long for the server (at most {max} bytes).', { max: sizeLimits.subject })
+    : null;
+  const bodyTooLong = oversize.body && sizeLimits
+    ? t('settings.vacation.warnings.body_too_long', 'The message is too long for the server (at most {max} bytes, formatting included).', { max: sizeLimits.body })
+    : null;
+
   const warnings: string[] = [];
   if (endBeforeStart) warnings.push(t('settings.vacation.warnings.end_before_start', 'End date must be after start date'));
   if (startInPast) warnings.push(t('settings.vacation.warnings.start_in_past', 'Start date is in the past'));
@@ -155,7 +179,8 @@ export function VacationSettings() {
     forwardChanged ||
     audienceChanged;
 
-  const canSave = hasChanges && !endBeforeStart && !formatError && !forwardInvalid && !store.isSaving;
+  const canSave = hasChanges && !endBeforeStart && !formatError && !forwardInvalid
+    && !oversize.subject && !oversize.body && !store.isSaving;
 
   const handleSave = useCallback(async () => {
     // Read the live editor DOM rather than trusting onChange state (issue #9).
@@ -342,8 +367,9 @@ export function VacationSettings() {
             placeholder={t('settings.vacation.message.subject_placeholder', 'Out of Office')}
             placeholderTextColor={c.mutedForeground}
             accessibilityLabel={t('settings.vacation.message.subject_label', 'Subject')}
-            style={styles.subjectInput}
+            style={[styles.subjectInput, oversize.subject && styles.inputInvalid]}
           />
+          {subjectTooLong && <Text style={styles.fieldError}>{subjectTooLong}</Text>}
         </View>
         <View style={styles.bodyBlock}>
           <Text style={styles.bodyLabel}>{t('settings.vacation.message.body_label', 'Message Body')}</Text>
@@ -353,11 +379,12 @@ export function VacationSettings() {
             onChangeText={setBody}
             placeholder={t('settings.vacation.message.body_placeholder', 'Thank you for your email. I am currently out of the office and will respond when I return.')}
             placeholderTextColor={c.mutedForeground}
-            style={styles.bodyInput}
+            style={[styles.bodyInput, oversize.body && styles.inputInvalid]}
             multiline
             numberOfLines={6}
             textAlignVertical="top"
           />
+          {bodyTooLong && <Text style={styles.fieldError}>{bodyTooLong}</Text>}
         </View>
         <SettingItem
           label={t('settings.vacation.message.html_label', 'Formatted message (HTML)')}
@@ -466,6 +493,11 @@ export function VacationSettings() {
                   accessibilityLabel={t('settings.vacation.forward.keep_label', 'Keep in inbox')}
                 />
               </SettingItem>
+              {forwardOverLimit && (
+                <Text style={styles.forwardWarning}>
+                  {t('settings.filters.forward_limit', 'Forward limit per message on this server: {count}. Extra forwards are skipped.', { count: forwardLimit })}
+                </Text>
+              )}
             </>
           )}
         </SettingsSection>
@@ -570,6 +602,8 @@ function makeStyles(c: ThemePalette) {
     ...typography.body,
   },
   inputInvalid: { borderColor: c.error },
+  fieldError: { ...typography.caption, color: c.error, marginTop: spacing.xs },
+  forwardWarning: { ...typography.caption, color: c.warning, paddingHorizontal: spacing.lg, paddingBottom: spacing.md },
   subjectInput: {
     paddingHorizontal: spacing.md,
     paddingVertical: 6,