fix: harden discord media fallback regressions (#28906) (thanks @Sid-Qin)

CHANGELOG.md

@@ -111,6 +111,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Discord/Inbound media fallback: preserve attachment and sticker metadata when Discord CDN fetch/save fails by keeping URL-based media entries in context, with regression coverage for save failures and mixed success/failure ordering. Landed from contributor PR #28906 by @Sid-Qin. Thanks @Sid-Qin.
 - Docs/Docker images: clarify the official GHCR image source and tag guidance (`main`, `latest`, `<version>`), and document that `OPENCLAW_IMAGE` skips local image builds but still uses the repo-local compose/setup flow. (#27214, #31180) Fixes #15655. Thanks @ipl31.
 - Agents/Model fallback: classify additional network transport errors (`ECONNREFUSED`, `ENETUNREACH`, `EHOSTUNREACH`, `ENETRESET`, `EAI_AGAIN`) as failover-worthy so fallback chains advance when primary providers are unreachable. Landed from contributor PR #19077 by @ayanesakura. Thanks @ayanesakura.
 - Agents/Copilot token refresh: refresh GitHub Copilot runtime API tokens after auth-expiry failures and re-run with the renewed token so long-running embedded/subagent turns do not fail on mid-session 401 expiry. Landed from contributor PR #8805 by @Arthur742Ramos. Thanks @Arthur742Ramos.

src/discord/monitor/message-utils.test.ts

@@ -334,6 +334,83 @@ describe("resolveMediaList", () => {
     ]);
   });
 
+  it("falls back to URL when saveMediaBuffer fails", async () => {
+    const attachment = {
+      id: "att-save-fail",
+      url: "https://cdn.discordapp.com/attachments/1/photo.png",
+      filename: "photo.png",
+      content_type: "image/png",
+    };
+    fetchRemoteMedia.mockResolvedValueOnce({
+      buffer: Buffer.from("image"),
+      contentType: "image/png",
+    });
+    saveMediaBuffer.mockRejectedValueOnce(new Error("disk full"));
+
+    const result = await resolveMediaList(
+      asMessage({
+        attachments: [attachment],
+      }),
+      512,
+    );
+
+    expect(fetchRemoteMedia).toHaveBeenCalledTimes(1);
+    expect(saveMediaBuffer).toHaveBeenCalledTimes(1);
+    expect(result).toEqual([
+      {
+        path: attachment.url,
+        contentType: "image/png",
+        placeholder: "<media:image>",
+      },
+    ]);
+  });
+
+  it("preserves downloaded attachments alongside failed ones", async () => {
+    const goodAttachment = {
+      id: "att-good",
+      url: "https://cdn.discordapp.com/attachments/1/good.png",
+      filename: "good.png",
+      content_type: "image/png",
+    };
+    const badAttachment = {
+      id: "att-bad",
+      url: "https://cdn.discordapp.com/attachments/1/bad.pdf",
+      filename: "bad.pdf",
+      content_type: "application/pdf",
+    };
+
+    fetchRemoteMedia
+      .mockResolvedValueOnce({
+        buffer: Buffer.from("image"),
+        contentType: "image/png",
+      })
+      .mockRejectedValueOnce(new Error("network timeout"));
+    saveMediaBuffer.mockResolvedValueOnce({
+      path: "/tmp/good.png",
+      contentType: "image/png",
+    });
+
+    const result = await resolveMediaList(
+      asMessage({
+        attachments: [goodAttachment, badAttachment],
+      }),
+      512,
+    );
+
+    expect(result).toEqual([
+      {
+        path: "/tmp/good.png",
+        contentType: "image/png",
+        placeholder: "<media:image>",
+      },
+      {
+        path: badAttachment.url,
+        contentType: "application/pdf",
+        placeholder: "<media:document>",
+      },
+    ]);
+  });
+
   it("keeps sticker metadata when sticker download fails", async () => {
     const sticker = {
       id: "sticker-fallback",