XREADGROUP with NOACK should propagate only one XGROUP SETID command

src/t_stream.c

@@ -935,6 +935,8 @@ size_t streamReplyWithRange(client *c, stream *s, streamID *start, streamID *end
     streamIterator si;
     int64_t numfields;
     streamID id;
+    int propagate_last_id = 0;
+    int noack = flags & STREAM_RWR_NOACK;
 
     /* If the client is asking for some history, we serve it using a
      * different function, so that we return entries *solely* from its
@@ -950,12 +952,14 @@ size_t streamReplyWithRange(client *c, stream *s, streamID *start, streamID *end
         arraylen_ptr = addReplyDeferredLen(c);
     streamIteratorStart(&si,s,start,end,rev);
     while(streamIteratorGetID(&si,&id,&numfields)) {
-        int propagate_last_id = 0;
-
         /* Update the group last_id if needed. */
         if (group && streamCompareID(&id,&group->last_id) > 0) {
             group->last_id = id;
-            propagate_last_id = 1;
+            /* Group last id should be propagated only if NOACK was
+             * specified, otherwise the last id would be included
+             * in XCLAIM. */
+            if (noack)
+                propagate_last_id = 1;
         }
 
         /* Emit a two elements array for each item. The first is
@@ -983,7 +987,7 @@ size_t streamReplyWithRange(client *c, stream *s, streamID *start, streamID *end
          * XGROUP SETID command. So if we find that there is already
          * a NACK for the entry, we need to associate it to the new
          * consumer. */
-        if (group && !(flags & STREAM_RWR_NOACK)) {
+        if (group && !noack) {
             unsigned char buf[sizeof(streamID)];
             streamEncodeID(buf,&id);
 
@@ -1020,14 +1024,16 @@ size_t streamReplyWithRange(client *c, stream *s, streamID *start, streamID *end
                 streamPropagateXCLAIM(c,spi->keyname,group,spi->groupname,idarg,nack);
                 decrRefCount(idarg);
             }
-        } else {
-            if (propagate_last_id)
-                streamPropagateGroupID(c,spi->keyname,group,spi->groupname);
         }
 
         arraylen++;
         if (count && count == arraylen) break;
     }
+
+    if (spi && propagate_last_id) {
+        streamPropagateGroupID(c,spi->keyname,group,spi->groupname);
+    }
+
     streamIteratorStop(&si);
     if (arraylen_ptr) setDeferredArrayLen(c,arraylen_ptr,arraylen);
     return arraylen;