Merge pull request #2423 from chriseth/exportStateCrash

Prevent crash if not compiled with FATDB.

alethzero/ExportState.cpp

@@ -127,6 +127,8 @@ void ExportStateDialog::fillContracts()
 	ui->contracts->clear();
 	ui->accounts->setEnabled(true);
 	ui->contracts->setEnabled(true);
+	try
+	{
 		for (auto i: ethereum()->addresses(m_block))
 		{
 			string r = m_main->render(i);
@@ -134,6 +136,14 @@ void ExportStateDialog::fillContracts()
 				->setData(Qt::UserRole, QByteArray((char const*)i.data(), Address::size));
 		}
 	}
+	catch (InterfaceNotSupported const&)
+	{
+		ui->accounts->setEnabled(false);
+		ui->contracts->setEnabled(false);
+		ui->json->setEnabled(false);
+		ui->json->setText(QString("This feature requires compilation with FATDB support."));
+	}
+}
 
 void ExportStateDialog::generateJSON()
 {