Add Gloas bid gas limit test after an empty parent

tests/core/pyspec/eth_consensus_specs/test/gloas/networking/test_gossip_execution_payload_bid.py

@@ -10,6 +10,7 @@
     activate_builders,
     build_signed_bid,
     get_blocks_meta,
+    record_block_in_store,
     record_head_payload,
     setup_store_advanced_for_bid,
     setup_store_finalized_with_pending_payment,
@@ -2464,6 +2465,147 @@ def _run_bid_gas_limit_scenario(
     yield "messages", "meta", messages
 
 
+@with_gloas_and_later
+@spec_state_test_with_matching_config
+def test_gossip_execution_payload_bid__valid_gas_limit_after_empty_parent(spec, state):
+    """A bid after an empty head uses its execution parent's gas limit."""
+    anchor_state = state.copy()
+    yield "topic", "meta", "execution_payload_bid"
+
+    store, blocks, _ = setup_store_advanced_for_bid(spec, state)
+
+    parent_gas_limit = spec.Uint64(30_000_000)
+    payload_block_hash = spec.Hash32(b"\xaa" * 32)
+    payload_block = build_empty_block_for_next_slot(spec, state)
+    payload_bid = payload_block.body.signed_execution_payload_bid.message
+    payload_bid.block_hash = payload_block_hash
+    payload_bid.gas_limit = parent_gas_limit
+    signed_payload_block = state_transition_and_sign_block(spec, state, payload_block)
+    payload_root = record_block_in_store(spec, store, signed_payload_block, state.copy())
+    blocks.append(signed_payload_block)
+
+    payload_state = state.copy()
+    signed_envelope = build_signed_execution_payload_envelope(
+        spec, payload_state, payload_root, signed_payload_block
+    )
+    store.payloads[payload_root] = signed_envelope.message
+
+    # Leave the next block's payload unreceived so it becomes the empty head.
+    empty_parent_gas_limit = spec.Uint64(30_029_295)
+    empty_parent = build_empty_block_for_next_slot(spec, state)
+    empty_parent_bid = empty_parent.body.signed_execution_payload_bid.message
+    empty_parent_bid.parent_block_hash = payload_block_hash
+    empty_parent_bid.gas_limit = empty_parent_gas_limit
+    signed_empty_parent = state_transition_and_sign_block(spec, state, empty_parent)
+    parent_root = record_block_in_store(spec, store, signed_empty_parent, state.copy())
+    blocks.append(signed_empty_parent)
+
+    finalized_checkpoint_meta = activate_builders(spec, state, store, blocks)
+    yield "state", anchor_state
+    for signed in blocks:
+        yield get_filename(signed), signed
+    yield get_filename(signed_envelope), signed_envelope
+    blocks_meta = get_blocks_meta(blocks)
+    blocks_meta[-2]["payload"] = get_filename(signed_envelope)
+    yield "blocks", "meta", blocks_meta
+    yield "finalized_checkpoint", "meta", finalized_checkpoint_meta
+
+    seen = get_seen(spec)
+    time_ms = spec.compute_time_at_slot_ms(store, state.slot)
+    yield "current_time_ms", "meta", int(time_ms)
+    messages = []
+    common_fee = spec.ExecutionAddress(b"\x11" * 20)
+
+    proposal_slot, validator_index = find_upcoming_proposal_slot(spec, state)
+    time_ms += 50
+    signed_prefs = build_signed_proposer_preferences(
+        spec,
+        state,
+        proposal_slot=proposal_slot,
+        validator_index=validator_index,
+        fee_recipient=common_fee,
+        target_gas_limit=spec.Uint64(60_000_000),
+    )
+    yield get_filename(signed_prefs), signed_prefs
+    result, reason = run_validate_gossip(
+        spec,
+        seen=seen,
+        store=store,
+        signed_proposer_preferences=signed_prefs,
+        current_time_ms=time_ms,
+    )
+    assert result == "valid"
+    assert reason is None
+    messages.append(
+        {
+            "current_time_ms": int(time_ms),
+            "message": get_filename(signed_prefs),
+            "expected": result,
+        }
+    )
+
+    time_ms += 10
+    result, reason = run_validate_gossip(
+        spec,
+        seen=seen,
+        store=store,
+        signed_execution_payload_envelope=signed_envelope,
+    )
+    assert result == "valid"
+    assert reason is None
+    messages.append(
+        {
+            "current_time_ms": int(time_ms),
+            "message": get_filename(signed_envelope),
+            "expected": result,
+        }
+    )
+
+    signed_bid = build_signed_bid(
+        spec,
+        state,
+        builder_index=spec.BuilderIndex(0),
+        slot=proposal_slot,
+        parent_block_hash=payload_block_hash,
+        parent_block_root=parent_root,
+        fee_recipient=common_fee,
+        gas_limit=empty_parent_gas_limit,
+        value=spec.Gwei(1),
+    )
+    yield get_filename(signed_bid), signed_bid
+
+    assert spec.is_gas_limit_target_compatible(
+        parent_gas_limit,
+        signed_bid.message.gas_limit,
+        signed_prefs.message.target_gas_limit,
+    )
+    assert not spec.is_gas_limit_target_compatible(
+        empty_parent_gas_limit,
+        signed_bid.message.gas_limit,
+        signed_prefs.message.target_gas_limit,
+    )
+
+    time_ms += 40
+    result, reason = run_validate_gossip(
+        spec,
+        seen=seen,
+        store=store,
+        signed_execution_payload_bid=signed_bid,
+        current_time_ms=time_ms,
+    )
+    assert result == "valid"
+    assert reason is None
+    messages.append(
+        {
+            "current_time_ms": int(time_ms),
+            "message": get_filename(signed_bid),
+            "expected": result,
+        }
+    )
+
+    yield "messages", "meta", messages
+
+
 @with_gloas_and_later
 @spec_state_test_with_matching_config
 def test_gossip_execution_payload_bid__valid_gas_limit_increase_within_limit(spec, state):