From ea65182f033eca73c291057dacd54f8e4e809fbd Mon Sep 17 00:00:00 2001
From: John Newbery <john@johnnewbery.com>
Date: Thu, 28 Jun 2018 13:36:28 -0400
Subject: [PATCH] [wallet] loadwallet shouldn't create new wallets.
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A bug in the initial implementation of loadwallet meant that if the
arguement was a directory that didn't contain a wallet.dat file, a new
wallet would be created in that directory. Fix that so that if a
directory is passed in, it must contain a wallet.dat file.

Bug reported by promag (João Barbosa).
---
 src/wallet/rpcwallet.cpp              | 6 ++++++
 test/functional/wallet_multiwallet.py | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index bc381d3cd..9576d1a79 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -3092,6 +3092,12 @@ static UniValue loadwallet(const JSONRPCRequest& request)
     fs::path wallet_path = fs::absolute(wallet_file, GetWalletDir());
     if (fs::symlink_status(wallet_path).type() == fs::file_not_found) {
         throw JSONRPCError(RPC_WALLET_NOT_FOUND, "Wallet " + wallet_file + " not found.");
+    } else if (fs::is_directory(wallet_path)) {
+        // The given filename is a directory. Check that there's a wallet.dat file.
+        fs::path wallet_dat_file = wallet_path / "wallet.dat";
+        if (fs::symlink_status(wallet_dat_file).type() == fs::file_not_found) {
+            throw JSONRPCError(RPC_WALLET_NOT_FOUND, "Directory " + wallet_file + " does not contain a wallet.dat file.");
+        }
     }
 
     std::string warning;
diff --git a/test/functional/wallet_multiwallet.py b/test/functional/wallet_multiwallet.py
index 3cefd8345..fa5a2154a 100755
--- a/test/functional/wallet_multiwallet.py
+++ b/test/functional/wallet_multiwallet.py
@@ -211,6 +211,10 @@ class MultiWalletTest(BitcoinTestFramework):
         # Fail to load if wallet file is a symlink
         assert_raises_rpc_error(-4, "Wallet file verification failed: Invalid -wallet path 'w8_symlink'", self.nodes[0].loadwallet, 'w8_symlink')
 
+        # Fail to load if a directory is specified that doesn't contain a wallet
+        os.mkdir(wallet_dir('empty_wallet_dir'))
+        assert_raises_rpc_error(-18, "Directory empty_wallet_dir does not contain a wallet.dat file", self.nodes[0].loadwallet, 'empty_wallet_dir')
+
         self.log.info("Test dynamic wallet creation.")
 
         # Fail to create a wallet if it already exists.