Fixes #1483

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationActivityV2.kt

@@ -298,6 +298,13 @@ class ConversationActivityV2 : PassphraseRequiredActionBarActivity(), InputBarDe
     private val reverseMessageList = false
 
     private val adapter by lazy {
+
+        // To prevent repeated attachment download jobs being spawned we'll keep a set of what
+        // attachmentId / mmsId pairs we've already attempted to download and only spawn the job
+        // if we haven't already done so. Without this then when the retry limit for a failed job
+        // hits another job is immediately spawned (endlessly).
+        var alreadyAttemptedAttachmentDownloadPairs = mutableSetOf<Pair<Long, Long>>()
+
         val cursor = mmsSmsDb.getConversation(viewModel.threadId, reverseMessageList)
         val adapter = ConversationAdapter(
             this,
@@ -325,9 +332,15 @@ class ConversationActivityV2 : PassphraseRequiredActionBarActivity(), InputBarDe
                 }
             },
             onAttachmentNeedsDownload = { attachmentId, mmsId ->
-                // Start download (on IO thread)
-                lifecycleScope.launch(Dispatchers.IO) {
-                    JobQueue.shared.add(AttachmentDownloadJob(attachmentId, mmsId))
+                // Keep track of this specific attachment so we don't download it again
+                val pair = Pair(attachmentId, mmsId)
+                if (!alreadyAttemptedAttachmentDownloadPairs.contains(pair)) {
+                    alreadyAttemptedAttachmentDownloadPairs.add(pair)
+
+                    // Start download (on IO thread)
+                    lifecycleScope.launch(Dispatchers.IO) {
+                        JobQueue.shared.add(AttachmentDownloadJob(attachmentId, mmsId))
+                    }
                 }
             },
             glide = glide,
@@ -335,8 +348,8 @@ class ConversationActivityV2 : PassphraseRequiredActionBarActivity(), InputBarDe
         )
         adapter.visibleMessageViewDelegate = this
 
-        // Register an AdapterDataObserver to scroll us to the bottom of the RecyclerView if we're
-        // already near the the bottom and the data changes.
+        // Register an AdapterDataObserver to scroll us to the bottom of the RecyclerView for if
+        // we're already near the the bottom and the data changes.
         adapter.registerAdapterDataObserver(ConversationAdapterDataObserver(binding?.conversationRecyclerView!!, adapter))
 
         adapter

app/src/main/java/org/thoughtcrime/securesms/database/MmsSmsDatabase.java

@@ -305,7 +305,12 @@ public class MmsSmsDatabase extends Database {
     }
 
     String order = MmsSmsColumns.NORMALIZED_DATE_SENT + " DESC";
-    String selection = MmsSmsColumns.THREAD_ID + " = " + threadId;
+
+    // As the MmsSmsDatabase.ADDRESS column never contains the sender address we have to get creative to filter down all the
+    // messages that have been sent without interrogating each MessageRecord returned by the cursor. One way to do this is
+    // via the fact that the `ADDRESS_DEVICE_ID` is always null for incoming messages, but always has a value (such as 1) for
+    // outgoing messages - so we'll filter our query for only records with non-null ADDRESS_DEVICE_IDs in the current thread.
+    String selection = MmsSmsColumns.THREAD_ID + " = " + threadId + " AND " + MmsSmsColumns.ADDRESS_DEVICE_ID + " IS NOT NULL";
 
     // Try everything with resources so that they auto-close on end of scope
     try (Cursor cursor = queryTables(PROJECTION, selection, order, null)) {