Merge #16963: wallet: Fix unique_ptr usage in boost::signals2

6d6a7a8403ae923f189812edebdd95761de0e7f2 gui: Fix duplicate wallet showing up (João Barbosa)
81ea66c30e2953dee24d5b127c28daa0d9452a28 Drop signal CClientUIInterface::LoadWallet (Russell Yanofsky)

Pull request description:

  This PR includes 2 fixes:
   - prevent GUI LoadWallet handlers from crashing on startup when multiple handlers are attached, because the first handler takes ownership of the wallet unique pointer. Now every handler will receive its own unique pointer;

   - prevent showing a wallet twice in the GUI on startup due to a race with `loadwallet`.

  Fixes #16937

ACKs for top commit:
  fjahr:
    code review ACK 6d6a7a8403ae923f189812edebdd95761de0e7f2
  ryanofsky:
    Code review ACK 6d6a7a8403ae923f189812edebdd95761de0e7f2. No changes since last ACK other than rebase due to #17070
  kallewoof:
    Code review ACK 6d6a7a8403ae923f189812edebdd95761de0e7f2

Tree-SHA512: 7f0658c9011f81dfa176a094c2263448ee1d14fda7dc94e8b55ee9c8b81538bd2d1e4bf8a8dbfcd029ebfc9feb6d3cda9dee3f911122df0a4b1e0ca75f653ba4

1 files changed, 8 insertions, 2 deletions

diff --git a/src/dummywallet.cpp b/src/dummywallet.cpp
index 2fa1ad59da..1bc4e7ef72 100644
--- a/src/dummywallet.cpp
+++ b/src/dummywallet.cpp
@@ -11,6 +11,8 @@ enum class WalletCreationStatus;
 
 namespace interfaces {
 class Chain;
+class Handler;
+class Wallet;
 }
 
 class DummyWalletInit : public WalletInitInterface {
@@ -80,9 +82,13 @@ WalletCreationStatus CreateWallet(interfaces::Chain& chain, const SecureString&
     throw std::logic_error("Wallet function called in non-wallet build.");
 }
 
-namespace interfaces {
+using LoadWalletFn = std::function<void(std::unique_ptr<interfaces::Wallet> wallet)>;
+std::unique_ptr<interfaces::Handler> HandleLoadWallet(LoadWalletFn load_wallet)
+{
+    throw std::logic_error("Wallet function called in non-wallet build.");
+}
 
-class Wallet;
+namespace interfaces {
 
 std::unique_ptr<Wallet> MakeWallet(const std::shared_ptr<CWallet>& wallet)
 {