bitcoin-tx: Reject + sign in nversion parsing

It would be confusing to specify the sign for an unsigned value here, so
reject it.

Author: MarcoFalke

src/bitcoin-tx.cpp

@@ -211,12 +211,11 @@ static CAmount ExtractAndValidateValue(const std::string& strValue)
 
 static void MutateTxVersion(CMutableTransaction& tx, const std::string& cmdVal)
 {
-    uint32_t newVersion;
-    if (!ParseUInt32(cmdVal, &newVersion) || newVersion < 1 || newVersion > TX_MAX_STANDARD_VERSION) {
+    const auto ver{ToIntegral<uint32_t>(cmdVal)};
+    if (!ver || *ver < 1 || *ver > TX_MAX_STANDARD_VERSION) {
         throw std::runtime_error("Invalid TX version requested: '" + cmdVal + "'");
     }
-
-    tx.version = newVersion;
+    tx.version = *ver;
 }
 
 static void MutateTxLocktime(CMutableTransaction& tx, const std::string& cmdVal)

test/util/data/bitcoin-util-test.json

@@ -56,6 +56,12 @@
     "output_cmp": "blanktxv2.json",
     "description": "Creates a blank transaction when nothing is piped into bitcoin-tx (output in json)"
   },
+  { "exec": "./bitcoin-tx",
+    "args": ["-create", "nversion=+1"],
+    "return_code": 1,
+    "error_txt": "error: Invalid TX version requested",
+    "description": "Tests the check for invalid nversion value"
+  },
   { "exec": "./bitcoin-tx",
     "args": ["-create", "nversion=1foo"],
     "return_code": 1,