From 044809cd46d36710d26dd8984c12934b12e68e6e Mon Sep 17 00:00:00 2001
From: Julien Cabieces <julien.cabieces@oslandia.com>
Date: Wed, 25 Oct 2023 17:40:05 +0200
Subject: [PATCH] Fixes #54141 : increase expression widget text size for long
 expressions

---
 src/gui/qgsfieldexpressionwidget.cpp           |  5 +++++
 tests/src/gui/testqgsfieldexpressionwidget.cpp | 15 +++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/src/gui/qgsfieldexpressionwidget.cpp b/src/gui/qgsfieldexpressionwidget.cpp
index 3422ec9a2b1..8ed8ac0a849 100644
--- a/src/gui/qgsfieldexpressionwidget.cpp
+++ b/src/gui/qgsfieldexpressionwidget.cpp
@@ -190,6 +190,11 @@ void QgsFieldExpressionWidget::setField( const QString &fieldName )
     return;
   }
 
+  if ( fieldName.size() > mCombo->lineEdit()->maxLength() )
+  {
+    mCombo->lineEdit()->setMaxLength( fieldName.size() );
+  }
+
   QModelIndex idx = mFieldProxyModel->sourceFieldModel()->indexFromName( fieldName );
   if ( !idx.isValid() )
   {
diff --git a/tests/src/gui/testqgsfieldexpressionwidget.cpp b/tests/src/gui/testqgsfieldexpressionwidget.cpp
index 5a4d2370e28..da604d555a2 100644
--- a/tests/src/gui/testqgsfieldexpressionwidget.cpp
+++ b/tests/src/gui/testqgsfieldexpressionwidget.cpp
@@ -49,6 +49,7 @@ class TestQgsFieldExpressionWidget : public QObject
     void testIsValid();
     void testFilters();
     void setNull();
+    void testVeryLongExpression();
 
   private:
     QgsFieldExpressionWidget *mWidget = nullptr;
@@ -372,5 +373,19 @@ void TestQgsFieldExpressionWidget::setNull()
   QgsProject::instance()->removeMapLayer( layer );
 }
 
+void TestQgsFieldExpressionWidget::testVeryLongExpression()
+{
+  QString veryLongExpression;
+  for ( int i = 0; i < 32770; i++ )
+  {
+    veryLongExpression += "a";
+  }
+
+  mWidget->setExpression( veryLongExpression );
+  QCOMPARE( veryLongExpression.size(), mWidget->currentText().size() );
+};
+
+
+
 QGSTEST_MAIN( TestQgsFieldExpressionWidget )
 #include "testqgsfieldexpressionwidget.moc"