From ac2ede5bb1d55b4119b95f6420c55c20123783fc Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Mon, 16 Feb 2026 04:18:17 +0100
Subject: [PATCH] fix(telegram): treat no-op editMessage as success

---
 src/telegram/send.test.ts | 16 ++++++++++++++++
 src/telegram/send.ts      | 26 ++++++++++++++++++++++++--
 2 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/src/telegram/send.test.ts b/src/telegram/send.test.ts
index 690a4776db..db51b20914 100644
--- a/src/telegram/send.test.ts
+++ b/src/telegram/send.test.ts
@@ -1321,6 +1321,22 @@ describe("editMessageTelegram", () => {
     );
   });
 
+  it("treats 'message is not modified' as success", async () => {
+    botApi.editMessageText.mockRejectedValueOnce(
+      new Error(
+        "400: Bad Request: message is not modified: specified new message content and reply markup are exactly the same as a current content and reply markup of the message",
+      ),
+    );
+
+    await expect(
+      editMessageTelegram("123", 1, "hi", {
+        token: "tok",
+        cfg: {},
+      }),
+    ).resolves.toEqual({ ok: true, messageId: "1", chatId: "123" });
+    expect(botApi.editMessageText).toHaveBeenCalledTimes(1);
+  });
+
   it("disables link previews when linkPreview is false", async () => {
     botApi.editMessageText.mockResolvedValue({ message_id: 1, chat: { id: "123" } });
 
diff --git a/src/telegram/send.ts b/src/telegram/send.ts
index d4c4dd0e9b..ec451844f6 100644
--- a/src/telegram/send.ts
+++ b/src/telegram/send.ts
@@ -74,6 +74,8 @@ type TelegramReactionOpts = {
 
 const PARSE_ERR_RE = /can't parse entities|parse entities|find end of the entity/i;
 const THREAD_NOT_FOUND_RE = /400:\s*Bad Request:\s*message thread not found/i;
+const MESSAGE_NOT_MODIFIED_RE =
+  /400:\s*Bad Request:\s*message is not modified|MESSAGE_NOT_MODIFIED/i;
 const diagLogger = createSubsystemLogger("telegram/diagnostic");
 
 function createTelegramHttpLogger(cfg: ReturnType<typeof loadConfig>) {
@@ -182,6 +184,10 @@ function isTelegramThreadNotFoundError(err: unknown): boolean {
   return THREAD_NOT_FOUND_RE.test(formatErrorMessage(err));
 }
 
+function isTelegramMessageNotModifiedError(err: unknown): boolean {
+  return MESSAGE_NOT_MODIFIED_RE.test(formatErrorMessage(err));
+}
+
 function hasMessageThreadIdParam(params?: Record<string, unknown>): boolean {
   if (!params) {
     return false;
@@ -730,10 +736,15 @@ export async function editMessageTelegram(
     verbose: opts.verbose,
   });
   const logHttpError = createTelegramHttpLogger(cfg);
-  const requestWithDiag = <T>(fn: () => Promise<T>, label?: string) =>
+  const requestWithDiag = <T>(
+    fn: () => Promise<T>,
+    label?: string,
+    shouldLog?: (err: unknown) => boolean,
+  ) =>
     withTelegramApiErrorLogging({
       operation: label ?? "request",
       fn: () => request(fn, label),
+      shouldLog,
     }).catch((err) => {
       logHttpError(label ?? "request", err);
       throw err;
@@ -768,7 +779,12 @@ export async function editMessageTelegram(
   await requestWithDiag(
     () => api.editMessageText(chatId, messageId, htmlText, editParams),
     "editMessage",
+    (err) => !isTelegramMessageNotModifiedError(err),
   ).catch(async (err) => {
+    if (isTelegramMessageNotModifiedError(err)) {
+      return;
+    }
+
     // Telegram rejects malformed HTML. Fall back to plain text.
     const errText = formatErrorMessage(err);
     if (PARSE_ERR_RE.test(errText)) {
@@ -788,7 +804,13 @@ export async function editMessageTelegram(
             ? api.editMessageText(chatId, messageId, text, plainParams)
             : api.editMessageText(chatId, messageId, text),
         "editMessage-plain",
-      );
+        (plainErr) => !isTelegramMessageNotModifiedError(plainErr),
+      ).catch((plainErr) => {
+        if (isTelegramMessageNotModifiedError(plainErr)) {
+          return;
+        }
+        throw plainErr;
+      });
     }
     throw err;
   });