Move getNamePrevout close to name_firstupdate.

getNamePrevout is a helper method that is only used by name_firstupdate,
so it makes sense to move it close to that place.  The "general front"
of rpcnames.cpp should be used for things that are used by multiple
methods, like the DestinationAddressHelper and more things in the
future.

This is a pure code move, together with also moving
MAX_NAME_PREVOUT_TRIALS into the function.

src/wallet/rpcnames.cpp

@@ -23,51 +23,10 @@
 
 #include <memory>
 
+/* ************************************************************************** */
 namespace
 {
 
-// Maximum number of outputs that are checked for the NAME_NEW prevout.
-constexpr unsigned MAX_NAME_PREVOUT_TRIALS = 1000;
-
-/**
- * Helper routine to fetch the name output of a previous transaction.  This
- * is required for name_firstupdate.
- * @param txid Previous transaction ID.
- * @param txOut Set to the corresponding output.
- * @param txIn Set to the CTxIn to include in the new tx.
- * @return True if the output could be found.
- */
-bool
-getNamePrevout (const uint256& txid, CTxOut& txOut, CTxIn& txIn)
-{
-  AssertLockHeld (cs_main);
-
-  // Unfortunately, with the change of the txdb to be based on outputs rather
-  // than full transactions, we can no longer just look up the txid and iterate
-  // over all outputs.  Since this is only necessary for a corner case, we just
-  // keep trying with indices until we find the output (up to a maximum number
-  // of trials).
-
-  for (unsigned i = 0; i < MAX_NAME_PREVOUT_TRIALS; ++i)
-    {
-      const COutPoint outp(txid, i);
-
-      Coin coin;
-      if (!pcoinsTip->GetCoin (outp, coin))
-        continue;
-
-      if (!coin.out.IsNull ()
-          && CNameScript::isNameScript (coin.out.scriptPubKey))
-        {
-          txOut = coin.out;
-          txIn = CTxIn (outp);
-          return true;
-        }
-    }
-
-  return false;
-}
-
 /**
  * A simple helper class that handles determination of the address to which
  * name outputs should be sent.  It handles the CReserveKey reservation
@@ -160,8 +119,7 @@ std::string getNameOpOptionsHelp ()
          "  }\n";
 }
 
-} // namespace
-
+} // anonymous namespace
 /* ************************************************************************** */
 
 UniValue
@@ -345,6 +303,53 @@ name_new (const JSONRPCRequest& request)
 
 /* ************************************************************************** */
 
+namespace
+{
+
+/**
+ * Helper routine to fetch the name output of a previous transaction.  This
+ * is required for name_firstupdate.
+ * @param txid Previous transaction ID.
+ * @param txOut Set to the corresponding output.
+ * @param txIn Set to the CTxIn to include in the new tx.
+ * @return True if the output could be found.
+ */
+bool
+getNamePrevout (const uint256& txid, CTxOut& txOut, CTxIn& txIn)
+{
+  AssertLockHeld (cs_main);
+
+  // Maximum number of outputs that are checked for the NAME_NEW prevout.
+  constexpr unsigned MAX_NAME_PREVOUT_TRIALS = 1000;
+
+  // Unfortunately, with the change of the txdb to be based on outputs rather
+  // than full transactions, we can no longer just look up the txid and iterate
+  // over all outputs.  Since this is only necessary for a corner case, we just
+  // keep trying with indices until we find the output (up to a maximum number
+  // of trials).
+
+  for (unsigned i = 0; i < MAX_NAME_PREVOUT_TRIALS; ++i)
+    {
+      const COutPoint outp(txid, i);
+
+      Coin coin;
+      if (!pcoinsTip->GetCoin (outp, coin))
+        continue;
+
+      if (!coin.out.IsNull ()
+          && CNameScript::isNameScript (coin.out.scriptPubKey))
+        {
+          txOut = coin.out;
+          txIn = CTxIn (outp);
+          return true;
+        }
+    }
+
+  return false;
+}
+
+}  // anonymous namespace
+
 UniValue
 name_firstupdate (const JSONRPCRequest& request)
 {