Reject duplicate wallet filenames

src/wallet/wallet.cpp

@@ -468,13 +468,24 @@ bool CWallet::Verify()
 
     uiInterface.InitMessage(_("Verifying wallet(s)..."));
 
+    // Keep track of each wallet absolute path to detect duplicates.
+    std::set<fs::path> wallet_paths;
+
     for (const std::string& walletFile : gArgs.GetArgs("-wallet")) {
         if (boost::filesystem::path(walletFile).filename() != walletFile) {
             return InitError(_("-wallet parameter must only specify a filename (not a path)"));
-        } else if (SanitizeString(walletFile, SAFE_CHARS_FILENAME) != walletFile) {
+        }
+
+        if (SanitizeString(walletFile, SAFE_CHARS_FILENAME) != walletFile) {
             return InitError(_("Invalid characters in -wallet filename"));
         }
 
+        fs::path wallet_path = fs::absolute(walletFile, GetDataDir());
+
+        if (!wallet_paths.insert(wallet_path).second) {
+            return InitError(_("Duplicate -wallet filename"));
+        }
+
         std::string strError;
         if (!CWalletDB::VerifyEnvironment(walletFile, GetDataDir().string(), strError)) {
             return InitError(strError);

test/functional/multiwallet.py

@@ -18,6 +18,13 @@ class MultiWalletTest(BitcoinTestFramework):
         self.extra_args = [['-wallet=w1', '-wallet=w2', '-wallet=w3']]
 
     def run_test(self):
+        self.stop_node(0)
+
+        # should not initialize if there are duplicate wallets
+        self.assert_start_raises_init_error(0, self.options.tmpdir, ['-wallet=w1', '-wallet=w1'], 'Duplicate -wallet filename')
+
+        self.nodes[0] = self.start_node(0, self.options.tmpdir, self.extra_args[0])
+
         w1 = self.nodes[0] / "wallet/w1"
         w1.generate(1)