bitcoin-tx: Reject + sign in replaceable parsing

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

@@ -177,6 +177,15 @@
     "error_txt": "error: Invalid TX input index",
     "description": "Tests the check for an invalid string input index with replaceable"
   },
+  { "exec": "./bitcoin-tx",
+    "args":
+    ["-create",
+     "in=5897de6bd6027a475eadd57019d4e6872c396d0716c4875a5f1a6fcfdf385c1f:0",
+     "replaceable=+0"],
+    "return_code": 1,
+    "error_txt": "error: Invalid TX input index",
+    "description": "Tests the check for an invalid string input index with replaceable"
+  },
   {
     "exec": "./bitcoin-tx",
     "args":