gui: bugfix, getAvailableBalance skips selected coins

The previous behavior for getAvailableBalance when coin control
has selected coins was to return the sum of them. Instead, we
are currently returning the wallet's available total balance minus
the selected coins total amount.

This turns into a GUI-only issue for the "use available balance"
button when the user manually select coins in the send screen.

Reason:
We missed to update the GetAvailableBalance function to include
the coin control selected coins on #25685.

Context:
Since #25685 we skip the selected coins inside `AvailableCoins`,
the reason is that there is no need to traverse the wallet's
txes map just to get coins that can directly be fetched by
their id.

1 files changed, 6 insertions, 1 deletions

diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index e3fa4058a6..9c1d3f48e0 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -791,8 +791,13 @@ void SendCoinsDialog::useAvailableBalance(SendCoinsEntry* entry)
     // Include watch-only for wallets without private key
     m_coin_control->fAllowWatchOnly = model->wallet().privateKeysDisabled() && !model->wallet().hasExternalSigner();
 
+    // Same behavior as send: if we have selected coins, only obtain their available balance.
+    // Copy to avoid modifying the member's data.
+    CCoinControl coin_control = *m_coin_control;
+    coin_control.m_allow_other_inputs = !coin_control.HasSelected();
+
     // Calculate available amount to send.
-    CAmount amount = model->getAvailableBalance(m_coin_control.get());
+    CAmount amount = model->getAvailableBalance(&coin_control);
     for (int i = 0; i < ui->entries->count(); ++i) {
         SendCoinsEntry* e = qobject_cast<SendCoinsEntry*>(ui->entries->itemAt(i)->widget());
         if (e && !e->isHidden() && e != entry) {