From c96814db4cce74b03526f445ec072def2610fc28 Mon Sep 17 00:00:00 2001
From: Linus Rath <139418639+rathlinus@users.noreply.github.com>
Date: Wed, 23 Sep 2026 18:19:26 +0200
Subject: [PATCH] fix: hide the lite server field once config.json sets
 jmapServerUrl #1087

---
 lib/__tests__/lite-scripts.test.ts | 15 +++++++++++++--
 scripts/lite/lib.mjs               | 14 ++++++++++++--
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/lib/__tests__/lite-scripts.test.ts b/lib/__tests__/lite-scripts.test.ts
index 8f8e7e958..f8b5bbc05 100644
--- a/lib/__tests__/lite-scripts.test.ts
+++ b/lib/__tests__/lite-scripts.test.ts
@@ -60,6 +60,7 @@ import { runPostbuild } from '../../scripts/lite/postbuild.mjs';
 import { verifyExport } from '../../scripts/lite/verify.mjs';
 import { stageContainer } from '../../scripts/lite/container.mjs';
 import { LITE_PENDING_PATH_KEY as APP_LITE_PENDING_PATH_KEY } from '../lite';
+import { applyLiteConfig } from '../lite-config';
 
 /** The scripts take `process.env`-shaped input; tests pass plain objects. */
 function env(values: Record<string, string> = {}): NodeJS.ProcessEnv {
@@ -102,18 +103,28 @@ describe('lite build helpers', () => {
   it('derives config.json from the LITE_* inputs with safe defaults', () => {
     const empty = buildLiteConfig({});
     expect(empty.jmapServerUrl).toBe('');
-    expect(empty.allowCustomJmapEndpoint).toBe(true);
+    expect(empty).not.toHaveProperty('allowCustomJmapEndpoint');
+    expect(applyLiteConfig(empty).allowCustomJmapEndpoint).toBe(true);
     expect(empty.rememberMeEnabled).toBe(true);
     expect(empty.demoMode).toBe(false);
     expect(empty.appName).toBe('Bulwark Webmail');
 
     const fixed = buildLiteConfig({ LITE_JMAP_SERVER_URL: 'https://mail.example.com/', LITE_APP_NAME: 'Acme', LITE_DEMO_MODE: 'true', LITE_REMEMBER_ME: 'false' });
     expect(fixed.jmapServerUrl).toBe('https://mail.example.com');
-    expect(fixed.allowCustomJmapEndpoint).toBe(false);
+    expect(fixed).not.toHaveProperty('allowCustomJmapEndpoint');
+    expect(applyLiteConfig(fixed).allowCustomJmapEndpoint).toBe(false);
     expect(fixed.appName).toBe('Acme');
     expect(fixed.demoMode).toBe(true);
     expect(fixed.rememberMeEnabled).toBe(false);
     expect(buildLitePolicy().features).toEqual({ pluginsEnabled: false, sidebarAppsEnabled: false });
+    expect(buildLiteConfig({ LITE_ALLOW_CUSTOM_ENDPOINT: 'true' }).allowCustomJmapEndpoint).toBe(true);
+    expect(buildLiteConfig({ LITE_ALLOW_CUSTOM_ENDPOINT: 'false' }).allowCustomJmapEndpoint).toBe(false);
+  });
+
+  it('hides the server field once a deployer fills in jmapServerUrl of the shipped config.json (#1087)', () => {
+    const shipped = buildLiteConfig({});
+    const edited = { ...shipped, jmapServerUrl: 'https://mail.example.com' };
+    expect(applyLiteConfig(edited).allowCustomJmapEndpoint).toBe(false);
   });
 
   it('prefixes manifest and redirect paths with the base path', () => {
diff --git a/scripts/lite/lib.mjs b/scripts/lite/lib.mjs
index 303436abe..02d86badd 100644
--- a/scripts/lite/lib.mjs
+++ b/scripts/lite/lib.mjs
@@ -139,17 +139,25 @@ export function normalizeBasePath(raw) {
  * config.json contents from the LITE_* build inputs. The Stalwart target is
  * served by the mail server itself: an empty server URL means "this origin"
  * there, so the server field stays hidden unless a build asks for it.
+ *
+ * The static target leaves `allowCustomJmapEndpoint` out unless the build sets
+ * it: the app then derives it from `jmapServerUrl` at runtime. Writing the
+ * derived `true` of an empty server URL kept the server field on the login
+ * page after a deployer filled in `jmapServerUrl` and nothing else (#1087).
  */
 export function buildLiteConfig(env = {}, { target = "static" } = {}) {
   const jmapServerUrl = (env.LITE_JMAP_SERVER_URL ?? "").trim().replace(/\/+$/, "");
   const stalwart = target === "stalwart";
+  const customEndpointSet = (env.LITE_ALLOW_CUSTOM_ENDPOINT ?? "") !== "";
   return {
     _comment: stalwart
       ? "Bulwark Lite for Stalwart. Read-only inside the Application bundle: to change it, build your own zip (see LITE-README.md). An empty jmapServerUrl means the Stalwart server that serves this page."
       : "Bulwark Lite runtime configuration. Edit and re-upload; no rebuild needed. See LITE-README.md.",
     appName: (env.LITE_APP_NAME ?? "").trim() || "Bulwark Webmail",
     jmapServerUrl,
-    allowCustomJmapEndpoint: parseBool(env.LITE_ALLOW_CUSTOM_ENDPOINT, !stalwart && jmapServerUrl === ""),
+    ...(stalwart || customEndpointSet
+      ? { allowCustomJmapEndpoint: parseBool(env.LITE_ALLOW_CUSTOM_ENDPOINT, false) }
+      : {}),
     rememberMeEnabled: parseBool(env.LITE_REMEMBER_ME, true),
     demoMode: parseBool(env.LITE_DEMO_MODE, false),
     loginShowTotp: true,
@@ -574,7 +582,9 @@ ${demoMode ? "Demo mode is ON: the login page offers a built-in demo account and
 2. Edit \`config.json\`:
    - \`jmapServerUrl\`: your mail server, e.g. \`https://mail.example.com\`${jmapServerUrl ? ` (currently \`${jmapServerUrl}\`)` : ""}.
    - \`appName\`: the name shown in the tab and on the login page.
-   - \`allowCustomJmapEndpoint\`: \`true\` shows a server field on the login page.
+   - \`allowCustomJmapEndpoint\` (optional): \`true\` always shows a server field
+     on the login page, \`false\` never does. Left out, the field shows only
+     while \`jmapServerUrl\` is empty.
    - \`rememberMeEnabled\`: \`false\` hides "remember me" (sessions then end with the tab).
    Optional keys: \`demoMode\`, \`jmapServers\`, \`jmapServerAutoPickByDomain\`, the login logo/company/link keys and \`loginShow*\` toggles (same names as the Docker env vars, camelCased).
 3. Allow the browser to talk to the mail server (CORS). In Stalwart: