Fix immediate sends with pending link previews

Signal.xcodeproj/project.pbxproj

@@ -594,6 +594,7 @@
 		4C6E6C6924241C00009DE948 /* ConversationViewControllerTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C6E6C6824241C00009DE948 /* ConversationViewControllerTest.swift */; };
 		4C751BE523FA0284002A8AF1 /* ContactSupportActionSheet.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C751BE423FA0284002A8AF1 /* ContactSupportActionSheet.swift */; };
 		4C83AC4223C55D9C00D4F2E6 /* SignalBaseTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C83AC4123C55D9C00D4F2E6 /* SignalBaseTest.swift */; };
+		C0D1E5012F0C000000000001 /* ThreadUtilSignalUITest.swift in Sources */ = {isa = PBXBuildFile; fileRef = C0D1E5002F0C000000000001 /* ThreadUtilSignalUITest.swift */; };
 		4C8A6DFC22E5499300469AE7 /* MediaZoomAnimationController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C8A6DFB22E5499300469AE7 /* MediaZoomAnimationController.swift */; };
 		4C8A6DFE22E54AFA00469AE7 /* MediaInteractiveDismiss.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C8A6DFD22E54AFA00469AE7 /* MediaInteractiveDismiss.swift */; };
 		4C9D347B23679C25006A4307 /* ContactStreamTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C9D347923679C13006A4307 /* ContactStreamTest.swift */; };
@@ -4828,6 +4829,7 @@
 		4C6F527B20FFE8400097DEEE /* SignalUBSan.supp */ = {isa = PBXFileReference; lastKnownFileType = text; path = SignalUBSan.supp; sourceTree = "<group>"; };
 		4C751BE423FA0284002A8AF1 /* ContactSupportActionSheet.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContactSupportActionSheet.swift; sourceTree = "<group>"; };
 		4C83AC4123C55D9C00D4F2E6 /* SignalBaseTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SignalBaseTest.swift; sourceTree = "<group>"; };
+		C0D1E5002F0C000000000001 /* ThreadUtilSignalUITest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ThreadUtilSignalUITest.swift; sourceTree = "<group>"; };
 		4C8A6DFB22E5499300469AE7 /* MediaZoomAnimationController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MediaZoomAnimationController.swift; sourceTree = "<group>"; };
 		4C8A6DFD22E54AFA00469AE7 /* MediaInteractiveDismiss.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MediaInteractiveDismiss.swift; sourceTree = "<group>"; };
 		4C9D347923679C13006A4307 /* ContactStreamTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContactStreamTest.swift; sourceTree = "<group>"; };
@@ -11645,6 +11647,7 @@
 				50791B1B2D037A7800D747F8 /* RecipientPickers */,
 				661278052996BA6700A1D5A1 /* Registration */,
 				040507132F80639B0078B769 /* RemoteReleaseNotes */,
+				C0D1E5022F0C000000000001 /* Sending */,
 				4C3EF8002109184A0007EBF7 /* SSKTests */,
 				D97046082E81D5B60034C05D /* Storage */,
 				E75DD3DC2810CD3500E32C36 /* subscriptions */,
@@ -11668,6 +11671,14 @@
 			path = contact;
 			sourceTree = "<group>";
 		};
+		C0D1E5022F0C000000000001 /* Sending */ = {
+			isa = PBXGroup;
+			children = (
+				C0D1E5002F0C000000000001 /* ThreadUtilSignalUITest.swift */,
+			);
+			path = Sending;
+			sourceTree = "<group>";
+		};
 		B660F69D1C29868000687D6E /* Supporting Files */ = {
 			isa = PBXGroup;
 			children = (
@@ -18874,6 +18885,7 @@
 				4C3EF802210918740007EBF7 /* SSKProtoEnvelopeTest.swift in Sources */,
 				8803FF6628EF89B50023574A /* StorySharingTests.swift in Sources */,
 				E75DD3E02810CDBD00E32C36 /* SubscriptionModelsTest.swift in Sources */,
+				C0D1E5012F0C000000000001 /* ThreadUtilSignalUITest.swift in Sources */,
 				5033D47329DCB3FF007FEADA /* UrlOpenerTest.swift in Sources */,
 				45A3579827DAAC6A0051CE8B /* UserProfileTest.swift in Sources */,
 				5042EAA3287F96FB00C9B19F /* VisibleBadgeResolverTest.swift in Sources */,

Signal/ConversationView/ConversationInputToolbar.swift

@@ -2001,6 +2001,12 @@ public class ConversationInputToolbar: UIView, QuotedReplyPreviewDelegate {
         return linkPreviewFetchState.linkPreviewDraftIfLoaded
     }
 
+    func consumeLinkPreviewDraftForSendingTask() -> Task<OWSLinkPreviewDraft?, Never>? {
+        AssertIsOnMainThread()
+
+        return linkPreviewFetchState.consumeLinkPreviewDraftForSendingTask()
+    }
+
     private func updateInputLinkPreview() {
         AssertIsOnMainThread()
 

Signal/ConversationView/ConversationViewController+ConversationInputToolbarDelegate.swift

@@ -136,6 +136,7 @@ extension ConversationViewController: ConversationInputToolbarDelegate {
                 // If its cleared, "change" it to nothing (clear it).
                 quotedReplyEdit: inputToolbar.quotedReplyDraft == nil ? .change(()) : .keep,
                 linkPreviewDraft: inputToolbar.linkPreviewDraft,
+                linkPreviewDraftForSending: inputToolbar.consumeLinkPreviewDraftForSendingTask(),
                 editTarget: editTarget,
                 persistenceCompletionHandler: {
                     AssertIsOnMainThread()
@@ -148,6 +149,7 @@ extension ConversationViewController: ConversationInputToolbarDelegate {
                 thread: self.thread,
                 quotedReplyDraft: inputToolbar.quotedReplyDraft,
                 linkPreviewDraft: inputToolbar.linkPreviewDraft,
+                linkPreviewDraftForSending: inputToolbar.consumeLinkPreviewDraftForSendingTask(),
                 persistenceCompletionHandler: {
                     AssertIsOnMainThread()
                     self.loadCoordinator.enqueueReload()

Signal/test/Sending/ThreadUtilSignalUITest.swift

@@ -0,0 +1,147 @@
+//
+// Copyright 2026 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+//
+
+import LibSignalClient
+import XCTest
+
+@testable import SignalServiceKit
+@testable import SignalUI
+
+final class ThreadUtilSignalUITest: SignalBaseTest {
+
+    private var thread: TSContactThread!
+
+    @MainActor
+    override func setUp() {
+        super.setUp()
+
+        ThreadUtil.enqueueSendQueue = SerialTaskQueue()
+        ThreadUtil.sendFinalizationQueue = SerialTaskQueue()
+
+        write { tx in
+            (DependenciesBridge.shared.registrationStateChangeManager as! RegistrationStateChangeManagerImpl)
+                .registerForTests(localIdentifiers: .forUnitTests, tx: tx)
+            SSKPreferences.setAreIntentDonationsEnabled(false, transaction: tx)
+
+            self.thread = TSContactThread.getOrCreateThread(
+                withContactAddress: SignalServiceAddress(Aci.randomForTesting()),
+                transaction: tx,
+            )
+        }
+    }
+
+    @MainActor
+    override func tearDown() {
+        ThreadUtil.enqueueSendQueue = SerialTaskQueue()
+        ThreadUtil.sendFinalizationQueue = SerialTaskQueue()
+
+        super.tearDown()
+    }
+
+    func testPendingLinkPreviewDoesNotBlockOutgoingRowPersistence() async throws {
+        let previewContinuation = AtomicValue<CheckedContinuation<OWSLinkPreviewDraft?, Never>?>(nil, lock: .init())
+        let previewTask = Task<OWSLinkPreviewDraft?, Never> {
+            await withCheckedContinuation { continuation in
+                previewContinuation.set(continuation)
+            }
+        }
+        let previewTaskIsWaiting = await waitUntil { previewContinuation.get() != nil }
+        XCTAssertTrue(previewTaskIsWaiting)
+
+        let firstMessageDidPersist = AtomicValue(false, lock: .init())
+        ThreadUtil.enqueueMessage(
+            body: MessageBody(text: "https://signal.org", ranges: .empty),
+            thread: thread,
+            linkPreviewDraftForSending: previewTask,
+            persistenceCompletionHandler: { firstMessageDidPersist.set(true) },
+        )
+
+        let firstMessagePersisted = await waitUntil(firstMessageDidPersist.get)
+        XCTAssertTrue(
+            firstMessagePersisted,
+            "The outgoing row should be visible before the pending preview resolves.",
+        )
+        if !firstMessagePersisted {
+            return
+        }
+
+        var outgoingMessages = self.outgoingMessages()
+        XCTAssertEqual(outgoingMessages.count, 1)
+        XCTAssertNil(outgoingMessages.first?.linkPreview)
+
+        let secondMessageDidPersist = AtomicValue(false, lock: .init())
+        ThreadUtil.enqueueMessage(
+            body: MessageBody(text: "second message", ranges: .empty),
+            thread: thread,
+            persistenceCompletionHandler: { secondMessageDidPersist.set(true) },
+        )
+
+        let secondMessagePersisted = await waitUntil(secondMessageDidPersist.get)
+        XCTAssertTrue(
+            secondMessagePersisted,
+            "A pending preview finalization should not block later outgoing rows from appearing.",
+        )
+        if !secondMessagePersisted {
+            return
+        }
+        outgoingMessages = self.outgoingMessages()
+        XCTAssertEqual(outgoingMessages.count, 2)
+        XCTAssertFalse(
+            self.messageSenderJobMessageIds().contains(outgoingMessages[0].uniqueId),
+            "The pending-preview message should hold an in-memory ordering barrier until finalization, not a runnable durable sender job.",
+        )
+
+        previewContinuation.swap(nil)?.resume(returning: OWSLinkPreviewDraft(
+            url: try XCTUnwrap(URL(string: "https://signal.org")),
+            title: "Signal",
+            isForwarded: false,
+        ))
+
+        try await ThreadUtil.enqueueSendQueue.enqueue(operation: {}).value
+        try await ThreadUtil.sendFinalizationQueue.enqueue(operation: {}).value
+
+        outgoingMessages = self.outgoingMessages()
+        XCTAssertEqual(outgoingMessages.count, 2)
+        XCTAssertEqual(outgoingMessages.first?.linkPreview?.urlString, "https://signal.org")
+        XCTAssertEqual(outgoingMessages.first?.linkPreview?.title, "Signal")
+    }
+
+    private func outgoingMessages() -> [TSOutgoingMessage] {
+        read { tx in
+            try! InteractionFinder(threadUniqueId: thread.uniqueId)
+                .fetchAllInteractions(rowIdFilter: .newest, limit: Int.max, tx: tx)
+                .compactMap { $0 as? TSOutgoingMessage }
+                .sorted { $0.timestamp < $1.timestamp }
+        }
+    }
+
+    private func messageSenderJobMessageIds() -> [String] {
+        read { tx in
+            MessageSenderJobRecord.anyFetchAll(transaction: tx)
+                .sorted { ($0.id ?? 0) < ($1.id ?? 0) }
+                .compactMap { jobRecord -> String? in
+                    guard case .persisted(let messageId, _) = jobRecord.messageType else {
+                        return nil
+                    }
+                    return messageId
+                }
+        }
+    }
+
+    private func waitUntil(
+        timeout: TimeInterval = 1,
+        _ predicate: @escaping () -> Bool,
+    ) async -> Bool {
+        let deadline = Date().addingTimeInterval(timeout)
+        while Date() < deadline {
+            if predicate() {
+                return true
+            }
+            try? await Task.sleep(nanoseconds: 10 * NSEC_PER_MSEC)
+        }
+
+        return predicate()
+    }
+}