From aaae94f00bf7634176cd588df993627ad4ae7e2d Mon Sep 17 00:00:00 2001
From: moneromooo-monero <moneromooo-monero@users.noreply.github.com>
Date: Sat, 16 Dec 2017 12:29:21 +0000
Subject: [PATCH] wallet2: reinstate the single preferred output selection

Removing it nullified the min-outputs-{count,value} system,
and will not increase the number of attempted transactions
in the general case.
---
 src/wallet/wallet2.cpp | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index e29e1051c..068923f0f 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -4827,7 +4827,19 @@ std::vector<size_t> wallet2::pick_preferred_rct_inputs(uint64_t needed_money, ui
 
   LOG_PRINT_L2("pick_preferred_rct_inputs: needed_money " << print_money(needed_money));
 
-  // try to find two outputs
+  // try to find a rct input of enough size
+  for (size_t i = 0; i < m_transfers.size(); ++i)
+  {
+    const transfer_details& td = m_transfers[i];
+    if (!td.m_spent && td.is_rct() && td.amount() >= needed_money && is_transfer_unlocked(td) && td.m_subaddr_index.major == subaddr_account && subaddr_indices.count(td.m_subaddr_index.minor) == 1)
+    {
+      LOG_PRINT_L2("We can use " << i << " alone: " << print_money(td.amount()));
+      picks.push_back(i);
+      return picks;
+    }
+  }
+
+  // then try to find two outputs
   // this could be made better by picking one of the outputs to be a small one, since those
   // are less useful since often below the needed money, so if one can be used in a pair,
   // it gets rid of it for the future