wallet: Forbid -salvagewallet, -zapwallettxes, and -upgradewallet with

multiple wallets

>>> backports bitcoin/bitcoin@9cbe8c8

Author: random-zebra

src/init.cpp

@@ -936,24 +936,6 @@ void InitParameterInteraction()
         if (gArgs.SoftSetBoolArg("-discover", false))
             LogPrintf("%s : parameter interaction: -externalip set -> setting -discover=0\n", __func__);
     }
-
-    if (gArgs.GetBoolArg("-salvagewallet", false)) {
-        // Rewrite just private keys: rescan to find transactions
-        if (gArgs.SoftSetBoolArg("-rescan", true))
-            LogPrintf("%s : parameter interaction: -salvagewallet=1 -> setting -rescan=1\n", __func__);
-    }
-
-    int zapwallettxes = gArgs.GetArg("-zapwallettxes", 0);
-    // -zapwallettxes implies dropping the mempool on startup
-    if (zapwallettxes != 0 && gArgs.SoftSetBoolArg("-persistmempool", false)) {
-        LogPrintf("%s: parameter interaction: -zapwallettxes=%s -> setting -persistmempool=0\n", __func__, zapwallettxes);
-    }
-
-    // -zapwallettxes implies a rescan
-    if (zapwallettxes != 0) {
-        if (gArgs.SoftSetBoolArg("-rescan", true))
-            LogPrintf("%s : parameter interaction: -zapwallettxes=%s -> setting -rescan=1\n", __func__, zapwallettxes);
-    }
 }
 
 bool InitNUParams()

src/wallet/wallet.cpp

@@ -654,6 +654,37 @@ bool CWallet::ParameterInteraction()
         return UIError("-sysperms is not allowed in combination with enabled wallet functionality");
     }
 
+    gArgs.SoftSetArg("-wallet", DEFAULT_WALLET_DAT);
+    const bool is_multiwallet = gArgs.GetArgs("-wallet").size() > 1;
+
+    if (gArgs.GetBoolArg("-salvagewallet", false) && gArgs.SoftSetBoolArg("-rescan", true)) {
+        if (is_multiwallet) {
+            return UIError(strprintf("%s is only allowed with a single wallet file", "-salvagewallet"));
+        }
+        // Rewrite just private keys: rescan to find transactions
+        LogPrintf("%s: parameter interaction: -salvagewallet=1 -> setting -rescan=1\n", __func__);
+    }
+
+    int zapwallettxes = gArgs.GetArg("-zapwallettxes", 0);
+    // -zapwallettxes implies dropping the mempool on startup
+    if (zapwallettxes != 0 && gArgs.SoftSetBoolArg("-persistmempool", false)) {
+        LogPrintf("%s: parameter interaction: -zapwallettxes=%s -> setting -persistmempool=0\n", __func__, zapwallettxes);
+    }
+
+    // -zapwallettxes implies a rescan
+    if (zapwallettxes != 0 && gArgs.SoftSetBoolArg("-rescan", true)) {
+        if (is_multiwallet) {
+            return UIError(strprintf("%s is only allowed with a single wallet file", "-zapwallettxes"));
+        }
+        LogPrintf("%s: parameter interaction: -zapwallettxes=<mode> -> setting -rescan=1\n", __func__);
+    }
+
+    if (is_multiwallet) {
+        if (gArgs.GetBoolArg("-upgradewallet", false)) {
+            return UIError(strprintf("%s is only allowed with a single wallet file", "-upgradewallet"));
+        }
+    }
+
     if (gArgs.IsArgSet("-mintxfee")) {
         CAmount n = 0;
         if (ParseMoney(gArgs.GetArg("-mintxfee", ""), n) && n > 0)
@@ -2080,7 +2111,6 @@ bool CWallet::Verify()
         return true;
     }
 
-    gArgs.SoftSetArg("-wallet", DEFAULT_WALLET_DAT);
     uiInterface.InitMessage(_("Verifying wallet(s)..."));
 
     for (const std::string& walletFile : gArgs.GetArgs("-wallet")) {