rpcwallet: default include_watchonly to true for watchonly wallets

The logic before would only include watchonly addresses if it was
explicitly set in the rpc argument.

This changes the logic like so:

If the include_watchonly argument is missing, check the
WALLET_FLAG_DISABLE_PRIVATE_KEYS flag to determine if we're working
with a watchonly wallet. If so, default include_watchonly to true.

If the include_watchonly argument is explicit set to false, we still
disable them from the listing. Although this would always return
nothing, it might be still useful in situations where you want to
explicitly filter out watchonly addresses regardless of what wallet
you are dealing with.

Signed-off-by: William Casarin <jb55@jb55.com>

src/wallet/rpcwallet.cpp

@@ -52,6 +52,23 @@ static inline bool GetAvoidReuseFlag(CWallet * const pwallet, const UniValue& pa
     return avoid_reuse;
 }
 
+
+/** Used by RPC commands that have an include_watchonly parameter.
+ *  We default to true for watchonly wallets if include_watchonly isn't
+ *  explicitly set.
+ */
+static bool ParseIncludeWatchonly(const UniValue& include_watchonly, const CWallet& pwallet)
+{
+    if (include_watchonly.isNull()) {
+        // if include_watchonly isn't explicitly set, then check if we have a watchonly wallet
+        return pwallet.IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS);
+    }
+
+    // otherwise return whatever include_watchonly was set to
+    return include_watchonly.get_bool();
+}
+
+
 /** Checks if a CKey is in the given CWallet compressed or otherwise*/
 bool HaveKey(const CWallet& wallet, const CKey& key)
 {
@@ -748,10 +765,7 @@ static UniValue getbalance(const JSONRPCRequest& request)
         min_depth = request.params[1].get_int();
     }
 
-    bool include_watchonly = false;
-    if (!request.params[2].isNull() && request.params[2].get_bool()) {
-        include_watchonly = true;
-    }
+    bool include_watchonly = ParseIncludeWatchonly(request.params[2], *pwallet);
 
     bool avoid_reuse = GetAvoidReuseFlag(pwallet, request.params[3]);
 
@@ -1033,9 +1047,10 @@ static UniValue ListReceived(interfaces::Chain::Lock& locked_chain, CWallet * co
         fIncludeEmpty = params[1].get_bool();
 
     isminefilter filter = ISMINE_SPENDABLE;
-    if(!params[2].isNull())
-        if(params[2].get_bool())
-            filter = filter | ISMINE_WATCH_ONLY;
+
+    if (ParseIncludeWatchonly(params[2], *pwallet)) {
+        filter |= ISMINE_WATCH_ONLY;
+    }
 
     bool has_filtered_address = false;
     CTxDestination filtered_address = CNoDestination();
@@ -1434,9 +1449,10 @@ UniValue listtransactions(const JSONRPCRequest& request)
     if (!request.params[2].isNull())
         nFrom = request.params[2].get_int();
     isminefilter filter = ISMINE_SPENDABLE;
-    if(!request.params[3].isNull())
-        if(request.params[3].get_bool())
-            filter = filter | ISMINE_WATCH_ONLY;
+
+    if (ParseIncludeWatchonly(request.params[3], *pwallet)) {
+        filter |= ISMINE_WATCH_ONLY;
+    }
 
     if (nCount < 0)
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Negative count");
@@ -1579,8 +1595,8 @@ static UniValue listsinceblock(const JSONRPCRequest& request)
         }
     }
 
-    if (!request.params[2].isNull() && request.params[2].get_bool()) {
-        filter = filter | ISMINE_WATCH_ONLY;
+    if (ParseIncludeWatchonly(request.params[2], *pwallet)) {
+        filter |= ISMINE_WATCH_ONLY;
     }
 
     bool include_removed = (request.params[3].isNull() || request.params[3].get_bool());
@@ -1697,9 +1713,10 @@ static UniValue gettransaction(const JSONRPCRequest& request)
     uint256 hash(ParseHashV(request.params[0], "txid"));
 
     isminefilter filter = ISMINE_SPENDABLE;
-    if(!request.params[1].isNull())
-        if(request.params[1].get_bool())
-            filter = filter | ISMINE_WATCH_ONLY;
+
+    if (ParseIncludeWatchonly(request.params[1], *pwallet)) {
+        filter |= ISMINE_WATCH_ONLY;
+    }
 
     UniValue entry(UniValue::VOBJ);
     auto it = pwallet->mapWallet.find(hash);
@@ -3014,8 +3031,7 @@ void FundTransaction(CWallet* const pwallet, CMutableTransaction& tx, CAmount& f
             }
         }
 
-        if (options.exists("includeWatching"))
-            coinControl.fAllowWatchOnly = options["includeWatching"].get_bool();
+        coinControl.fAllowWatchOnly = ParseIncludeWatchonly(options["includeWatching"], *pwallet);
 
         if (options.exists("lockUnspents"))
             lockUnspents = options["lockUnspents"].get_bool();
@@ -3047,6 +3063,9 @@ void FundTransaction(CWallet* const pwallet, CMutableTransaction& tx, CAmount& f
             }
         }
       }
+    } else {
+        // if options is null and not a bool
+        coinControl.fAllowWatchOnly = ParseIncludeWatchonly(NullUniValue, *pwallet);
     }
 
     if (tx.vout.size() == 0)