Merge #18192: Bugfix: Wallet: Safely deal with change in the address book

b5795a788639305bab86a8b3f6b75d6ce81be083 Wallet: Add warning comments and assert to CWallet::DelAddressBook (Luke Dashjr)
6d2905f57aaeb3ec3b63d31043f7673ca10003f2 Wallet: Avoid unnecessary/redundant m_address_book lookups (Luke Dashjr)
c751d886f499257627b308b11ffaa51c22db6cc0 Wallet: Avoid treating change-in-the-addressbook as non-change everywhere (Luke Dashjr)
8e64b8c84bcbd63caea06f3af087af1f0609eaf5 Wallet: New FindAddressBookEntry method to filter out change entries (and skip ->second everywhere) (Luke Dashjr)
65b6bdc2b164343ec3cc3d32a0297daff9e24fec Wallet: Add CAddressBookData::IsChange which returns true iff label has never been set (Luke Dashjr)
144b2f85da4d51bf7d72b987888ddcaf5b429eed Wallet: Require usage of new CAddressBookData::setLabel to change label (Luke Dashjr)
b86cd155f6f661052042048aa7cfc2a397afe4f7 scripted-diff: Wallet: Rename mapAddressBook to m_address_book (Luke Dashjr)

Pull request description:

  In many places, our code assumes that presence in the address book indicates a non-change key, and absence of an entry in mapAddressBook indicates change.

  This no longer holds true after #13756 (first released in 0.19) since it added a "used" DestData populated even for change addresses. Only avoid-reuse wallets should be affected by this issue.

  Thankfully, populating DestData does not write a label to the database, so we can retroactively fix this (so long as the user didn't see the change address and manually assign it a real label).

  Fixing it is accomplished by:

  * Adding a new bool to CAddressBookData to track if the label has ever been assigned, either by loading one from the database, or by assigning one at runtime.
  * `CAddressBookData::IsChange` and `CWallet::FindAddressBookEntry` are new methods to assist in excluding change from code that doesn't expect to see them.
  * For safety in merging, `CAddressBookData::name` has been made read-only (the actual data is stored in `m_label`, a new private member, and can be changed only with `setLabel` which updates the `m_change` flag), and `mapAddressBook` has been renamed to `m_address_book` (to force old code to be rebased to compile).

  A final commit also does some minor optimisation, avoiding redundant lookups in `m_address_book` when we already have a pointer to the `CAddressBookData`.

ACKs for top commit:
  ryanofsky:
    Code review ACK b5795a788639305bab86a8b3f6b75d6ce81be083. Pretty clever and nicely implemented fix!
  jonatack:
    ACK b5795a788639305bab86a8b3f6b75d6ce81be083 nice improvements -- code review, built/ran tests rebased on current master ff53433fe4ed06893d7c4 and tested manually with rpc/cli
  jnewbery:
    Good fix. utACK b5795a788.

Tree-SHA512: 40525185a0bcc1723f602243c269499ec86ecb298fecb5ef24d626bbdd5e3efece86cdb1084ad7eebf7eeaf251db4a6e056bcd25bc8457b417fcbb53d032ebf0

2 files changed, 2 insertions, 2 deletions

diff --git a/src/qt/addresstablemodel.cpp b/src/qt/addresstablemodel.cpp
index 3ac98a5970..3869318fea 100644
--- a/src/qt/addresstablemodel.cpp
+++ b/src/qt/addresstablemodel.cpp
@@ -55,7 +55,7 @@ struct AddressTableEntryLessThan
 static AddressTableEntry::Type translateTransactionType(const QString &strPurpose, bool isMine)
 {
     AddressTableEntry::Type addressType = AddressTableEntry::Hidden;
-    // "refund" addresses aren't shown, and change addresses aren't in mapAddressBook at all.
+    // "refund" addresses aren't shown, and change addresses aren't returned by getAddresses at all.
     if (strPurpose == "send")
         addressType = AddressTableEntry::Sending;
     else if (strPurpose == "receive")
diff --git a/src/qt/test/addressbooktests.cpp b/src/qt/test/addressbooktests.cpp
index 0f082802cc..042387286a 100644
--- a/src/qt/test/addressbooktests.cpp
+++ b/src/qt/test/addressbooktests.cpp
@@ -97,7 +97,7 @@ void TestAddAddressesToSendBook(interfaces::Node& node)
 
     auto check_addbook_size = [&wallet](int expected_size) {
         LOCK(wallet->cs_wallet);
-        QCOMPARE(static_cast<int>(wallet->mapAddressBook.size()), expected_size);
+        QCOMPARE(static_cast<int>(wallet->m_address_book.size()), expected_size);
     };
 
     // We should start with the two addresses we added earlier and nothing else.