Merge bitcoin/bitcoin#29736: test: Extends wait_for_getheaders so a specific block hash can be checked

c4f857cc301d856f3c60acbe6271d3fe19441c7a test: Extends wait_for_getheaders so a specific block hash can be checked (Sergi Delgado Segura)

Pull request description:

  Fixes https://github.com/bitcoin/bitcoin/issues/18614

  Previously, `wait_for_getheaders` would check whether a node had received **any** getheaders message. This implied that, if a test needed to check for a specific block hash within a headers message, it had to make sure that it was checking the desired message. This normally involved having to manually clear `last_message`. This method, apart from being too verbose, was error-prone, given an undesired `getheaders` would make tests pass.

  This adds the ability to check for a specific block_hash within the last `getheaders` message.

ACKs for top commit:
  achow101:
    ACK c4f857cc301d856f3c60acbe6271d3fe19441c7a
  BrandonOdiwuor:
    crACK c4f857cc301d856f3c60acbe6271d3fe19441c7a
  cbergqvist:
    ACK c4f857cc301d856f3c60acbe6271d3fe19441c7a
  stratospher:
    tested ACK c4f857c. went through all getheaders messages sent in the tests and checked that it's the one we want.

Tree-SHA512: afc9a31673344dfaaefcf692ec2ab65958c3d4c005f5f3af525e9960f0622d8246d5311e59aba06cfd5c9e0ef9eb90a7fc8e210f030bfbe67b897c061efdeed1

1 files changed, 9 insertions, 7 deletions

diff --git a/test/functional/test_framework/p2p.py b/test/functional/test_framework/p2p.py
index ce76008c46..00bd1e4017 100755
--- a/test/functional/test_framework/p2p.py
+++ b/test/functional/test_framework/p2p.py
@@ -644,15 +644,17 @@ class P2PInterface(P2PConnection):
 
         self.wait_until(test_function, timeout=timeout)
 
-    def wait_for_getheaders(self, *, timeout=60):
-        """Waits for a getheaders message.
+    def wait_for_getheaders(self, block_hash=None, *, timeout=60):
+        """Waits for a getheaders message containing a specific block hash.
 
-        Receiving any getheaders message will satisfy the predicate. the last_message["getheaders"]
-        value must be explicitly cleared before calling this method, or this will return
-        immediately with success. TODO: change this method to take a hash value and only
-        return true if the correct block header has been requested."""
+        If no block hash is provided, checks whether any getheaders message has been received by the node."""
         def test_function():
-            return self.last_message.get("getheaders")
+            last_getheaders = self.last_message.pop("getheaders", None)
+            if block_hash is None:
+                 return last_getheaders
+            if last_getheaders is None:
+                return False
+            return block_hash == last_getheaders.locator.vHave[0]
 
         self.wait_until(test_function, timeout=timeout)