Merge #9139: Change sync_blocks to pick smarter maxheight (on top of #9196)

1126c85 [qa] Change sync_blocks to pick smarter maxheight (Russell Yanofsky)

qa/rpc-tests/test_framework/util.py

@@ -129,17 +129,19 @@ def sync_blocks(rpc_connections, *, wait=1, timeout=60):
     one node already synced to the latest, stable tip, otherwise there's a
     chance it might return before all nodes are stably synced.
     """
-    maxheight = 0
+    # Use getblockcount() instead of waitforblockheight() to determine the
+    # initial max height because the two RPCs look at different internal global
+    # variables (chainActive vs latestBlock) and the former gets updated
+    # earlier.
+    maxheight = max(x.getblockcount() for x in rpc_connections)
     start_time = cur_time = time.time()
     while cur_time <= start_time + timeout:
         tips = [r.waitforblockheight(maxheight, int(wait * 1000)) for r in rpc_connections]
-        heights = [t["height"] for t in tips]
-        if all(t == tips[0] for t in tips):
-            return
-        if all(h == heights[0] for h in heights):
+        if all(t["height"] == maxheight for t in tips):
+            if all(t["hash"] == tips[0]["hash"] for t in tips):
+                return
             raise AssertionError("Block sync failed, mismatched block hashes:{}".format(
                                  "".join("\n  {!r}".format(tip) for tip in tips)))
-        maxheight = max(heights)
         cur_time = time.time()
     raise AssertionError("Block sync to height {} timed out:{}".format(
                          maxheight, "".join("\n  {!r}".format(tip) for tip in tips)))