Merge bitcoin/bitcoin#25024: test: Split MempoolAncestryTests into two

fa2102e test: Split MempoolAncestryTests into two (MacroFake)

Pull request description:

  The two tests don't share any state, so it seems clearer to put them in separate scopes.

ACKs for top commit:
  jnewbery:
    Code review ACK fa2102e

Tree-SHA512: 6669f50f8d5944fed55ecc88aa1bd139bddf6a40e3c2e8f88c3cc7e70cf6d4650c0dd652c7f304813893827c3930d626268655cd9b3f17ff9c9a1a02f0359714

Author: fanquake

src/test/mempool_tests.cpp

@@ -747,6 +747,15 @@ BOOST_AUTO_TEST_CASE(MempoolAncestryTests)
     pool.GetTransactionAncestry(ty6->GetHash(), ancestors, descendants);
     BOOST_CHECK_EQUAL(ancestors, 9ULL);
     BOOST_CHECK_EQUAL(descendants, 6ULL);
+}
+
+BOOST_AUTO_TEST_CASE(MempoolAncestryTestsDiamond)
+{
+    size_t ancestors, descendants;
+
+    CTxMemPool pool;
+    LOCK2(::cs_main, pool.cs);
+    TestMemPoolEntryHelper entry;
 
     /* Ancestors represented more than once ("diamond") */
     //
@@ -759,7 +768,6 @@ BOOST_AUTO_TEST_CASE(MempoolAncestryTests)
     tb = make_tx(/*output_values=*/{5 * COIN, 3 * COIN}, /*inputs=*/ {ta});
     tc = make_tx(/*output_values=*/{2 * COIN}, /*inputs=*/{tb}, /*input_indices=*/{1});
     td = make_tx(/*output_values=*/{6 * COIN}, /*inputs=*/{tb, tc}, /*input_indices=*/{0, 0});
-    pool.clear();
     pool.addUnchecked(entry.Fee(10000LL).FromTx(ta));
     pool.addUnchecked(entry.Fee(10000LL).FromTx(tb));
     pool.addUnchecked(entry.Fee(10000LL).FromTx(tc));