Merge #19441: walletdb: don't reinitialize desc cache with multiple cache entries

a66a7a1 walletdb: don't reinitialize desc cache with multiple cache entries (Andrew Chow)

Pull request description:

  When loading descriptor caches, we would accidentally reinitialize the descriptor cache when seeing that one already exists. This should have only been initializing the cache when one does not exist. However this code itself is unnecessary as the act of looking up the cache to add to it will initialize it if it didn't already exist.

  This issue could be hit by trying to load a wallet that had imported a multisig descriptor. The wallet would fail to load.

  A test has been added to wallet_importdescriptors.py to catch this case. Another test case has also been added to check that loading a wallet with only single key descriptors works.

ACKs for top commit:
  hugohn:
    tACK [a66a7a1](bitcoin/bitcoin@a66a7a1)
  jonatack:
    ACK a66a7a1
  meshcollider:
    Code review ACK a66a7a1

Tree-SHA512: 3df746421a008708eaa3bbbdd12b9ddd3e2ec111d54625a212dca7414b971cc1f6e2b1757b3232c31a2f637d1b1ef43bf3ffa4ac4216646cf1e92db5f79954f1

Author: meshcollider

src/wallet/walletdb.cpp

@@ -592,9 +592,6 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
             ssValue >> ser_xpub;
             CExtPubKey xpub;
             xpub.Decode(ser_xpub.data());
-            if (wss.m_descriptor_caches.count(desc_id)) {
-                wss.m_descriptor_caches[desc_id] = DescriptorCache();
-            }
             if (parent) {
                 wss.m_descriptor_caches[desc_id].CacheParentExtPubKey(key_exp_index, xpub);
             } else {

test/functional/wallet_importdescriptors.py

@@ -141,6 +141,14 @@ def run_test(self):
                               success=True)
         assert_equal(w1.getwalletinfo()['keypoolsize'], 0)
 
+        test_address(w1,
+                     key.p2sh_p2wpkh_addr,
+                     ismine=True,
+                     solvable=True)
+
+        # Check persistence of data and that loading works correctly
+        w1.unloadwallet()
+        self.nodes[1].loadwallet('w1')
         test_address(w1,
                      key.p2sh_p2wpkh_addr,
                      ismine=True,
@@ -370,6 +378,10 @@ def run_test(self):
         self.sync_all()
         assert_equal(wmulti_pub.getbalance(), wmulti_priv.getbalance())
 
+        # Make sure that descriptor wallets containing multiple xpubs in a single descriptor load correctly
+        wmulti_pub.unloadwallet()
+        self.nodes[1].loadwallet('wmulti_pub')
+
         self.log.info("Multisig with distributed keys")
         self.nodes[1].createwallet(wallet_name="wmulti_priv1", descriptors=True)
         wmulti_priv1 = self.nodes[1].get_wallet_rpc("wmulti_priv1")