Merge bitcoin/bitcoin#24026: Block unsafe std::string fs::path conversion copy_file calls

3a45dc36a663ea67f13e7d5c413518b9385ec594 Change type of `backup_file` parameter in RestoreWallet/restoreWallet (Hennadii Stepanov)
213172c7348091794b173c2edf5f7f3bbe010912 refactor: Block unsafe std::string fs::path conversion copy_file calls (Hennadii Stepanov)

Pull request description:

  This PR is an optional prerequisite for bitcoin/bitcoin#20744 "Use std::filesystem. Remove Boost Filesystem & System" which:
  - makes further code changes safer
  - prevents [some](https://cirrus-ci.com/task/6525835388649472) test failures on native Windows

ACKs for top commit:
  ryanofsky:
    Code review ACK 3a45dc36a663ea67f13e7d5c413518b9385ec594. Looks great! Thanks for debugging and fixing this and making #20744 smaller!

Tree-SHA512: c6dfaef6b45b9c268bc9ee9b943b9d679152c9d565ca4f86da8d33f8eb9b3cdbe9ba6df7b7578eacc0d00db6551048beff97419f86eb4b1d3182c43e2b4eb9a5

4 files changed, 6 insertions, 5 deletions

diff --git a/src/wallet/interfaces.cpp b/src/wallet/interfaces.cpp
index 64775a5ddb..0154225e00 100644
--- a/src/wallet/interfaces.cpp
+++ b/src/wallet/interfaces.cpp
@@ -557,7 +557,7 @@ public:
         options.require_existing = true;
         return MakeWallet(m_context, LoadWallet(m_context, name, true /* load_on_start */, options, status, error, warnings));
     }
-    std::unique_ptr<Wallet> restoreWallet(const std::string& backup_file, const std::string& wallet_name, bilingual_str& error, std::vector<bilingual_str>& warnings) override
+    std::unique_ptr<Wallet> restoreWallet(const fs::path& backup_file, const std::string& wallet_name, bilingual_str& error, std::vector<bilingual_str>& warnings) override
     {
         DatabaseStatus status;
 
diff --git a/src/wallet/rpc/backup.cpp b/src/wallet/rpc/backup.cpp
index 0029d1b09c..b77d3af3c6 100644
--- a/src/wallet/rpc/backup.cpp
+++ b/src/wallet/rpc/backup.cpp
@@ -1887,7 +1887,7 @@ RPCHelpMan restorewallet()
     bilingual_str error;
     std::vector<bilingual_str> warnings;
 
-    const std::shared_ptr<CWallet> wallet = RestoreWallet(context, fs::PathToString(backup_file), wallet_name, load_on_start, status, error, warnings);
+    const std::shared_ptr<CWallet> wallet = RestoreWallet(context, backup_file, wallet_name, load_on_start, status, error, warnings);
 
     HandleWalletError(wallet, status, error);
 
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 267710e8c7..4e40871073 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -357,12 +357,12 @@ std::shared_ptr<CWallet> CreateWallet(WalletContext& context, const std::string&
     return wallet;
 }
 
-std::shared_ptr<CWallet> RestoreWallet(WalletContext& context, const std::string& backup_file, const std::string& wallet_name, std::optional<bool> load_on_start, DatabaseStatus& status, bilingual_str& error, std::vector<bilingual_str>& warnings)
+std::shared_ptr<CWallet> RestoreWallet(WalletContext& context, const fs::path& backup_file, const std::string& wallet_name, std::optional<bool> load_on_start, DatabaseStatus& status, bilingual_str& error, std::vector<bilingual_str>& warnings)
 {
     DatabaseOptions options;
     options.require_existing = true;
 
-    if (!fs::exists(fs::u8path(backup_file))) {
+    if (!fs::exists(backup_file)) {
         error = Untranslated("Backup file does not exist");
         status = DatabaseStatus::FAILED_INVALID_BACKUP_FILE;
         return nullptr;
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index cbcdcaf3b8..c2abcfeea7 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -7,6 +7,7 @@
 #define BITCOIN_WALLET_WALLET_H
 
 #include <consensus/amount.h>
+#include <fs.h>
 #include <interfaces/chain.h>
 #include <interfaces/handler.h>
 #include <outputtype.h>
@@ -60,7 +61,7 @@ std::vector<std::shared_ptr<CWallet>> GetWallets(WalletContext& context);
 std::shared_ptr<CWallet> GetWallet(WalletContext& context, const std::string& name);
 std::shared_ptr<CWallet> LoadWallet(WalletContext& context, const std::string& name, std::optional<bool> load_on_start, const DatabaseOptions& options, DatabaseStatus& status, bilingual_str& error, std::vector<bilingual_str>& warnings);
 std::shared_ptr<CWallet> CreateWallet(WalletContext& context, const std::string& name, std::optional<bool> load_on_start, DatabaseOptions& options, DatabaseStatus& status, bilingual_str& error, std::vector<bilingual_str>& warnings);
-std::shared_ptr<CWallet> RestoreWallet(WalletContext& context, const std::string& backup_file, const std::string& wallet_name, std::optional<bool> load_on_start, DatabaseStatus& status, bilingual_str& error, std::vector<bilingual_str>& warnings);
+std::shared_ptr<CWallet> RestoreWallet(WalletContext& context, const fs::path& backup_file, const std::string& wallet_name, std::optional<bool> load_on_start, DatabaseStatus& status, bilingual_str& error, std::vector<bilingual_str>& warnings);
 std::unique_ptr<interfaces::Handler> HandleLoadWallet(WalletContext& context, LoadWalletFn load_wallet);
 std::unique_ptr<WalletDatabase> MakeWalletDatabase(const std::string& name, const DatabaseOptions& options, DatabaseStatus& status, bilingual_str& error);