Fix constraint check when AllowMulti

Fix #46366
qgis · Dec 11, 2021 · f7d48d8 · f7d48d8
1 parent d08d2fc
commit f7d48d8
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Showing 2 changed files with 28 additions and 8 deletions.
diff --git a/src/core/vector/qgsvectorlayerutils.cpp b/src/core/vector/qgsvectorlayerutils.cpp
@@ -431,9 +431,20 @@ bool QgsVectorLayerUtils::validateAttribute( const QgsVectorLayer *layer, const
 
     if ( !exempt )
     {
-      valid = valid && !value.isNull();
 
-      if ( value.isNull() )
+      const bool allowMulti { field.editorWidgetSetup().config().value( QStringLiteral( "AllowMulti" ), false ).toBool() };
+      bool multiViolated { false };
+      if ( allowMulti )
+      {
+        multiViolated = value == QStringLiteral( "{}" );
+        valid = valid && ( !value.isNull() && ! multiViolated );
+      }
+      else
+      {
+        valid = valid && !value.isNull();
+      }
+
+      if ( value.isNull() || multiViolated )
       {
         errors << QObject::tr( "value is NULL" );
         notNullConstraintViolated = true;

diff --git a/tests/src/python/test_qgsvectorlayerutils.py b/tests/src/python/test_qgsvectorlayerutils.py
@@ -32,6 +32,7 @@
                        QgsWkbTypes,
                        QgsCoordinateReferenceSystem,
                        QgsVectorLayerJoinInfo,
+                       QgsEditorWidgetSetup,
                        NULL
                        )
 from qgis.testing import start_app, unittest
@@ -266,7 +267,7 @@ def test_validate_attribute(self):
         # field expression check
         layer.setConstraintExpression(1, 'fldint>5')
 
-        f = QgsFeature(2)
+        f = QgsFeature(layer.fields(), 2)
         f.setAttributes(["test123", 6])
         res, errors = QgsVectorLayerUtils.validateAttribute(layer, f, 1)
         self.assertTrue(res)
@@ -275,7 +276,6 @@ def test_validate_attribute(self):
         res, errors = QgsVectorLayerUtils.validateAttribute(layer, f, 1)
         self.assertFalse(res)
         self.assertEqual(len(errors), 1)
-        print(errors)
         # checking only for provider constraints
         res, errors = QgsVectorLayerUtils.validateAttribute(layer, f, 1,
                                                             origin=QgsFieldConstraints.ConstraintOriginProvider)
@@ -287,7 +287,6 @@ def test_validate_attribute(self):
         res, errors = QgsVectorLayerUtils.validateAttribute(layer, f, 1)
         self.assertFalse(res)
         self.assertEqual(len(errors), 1)
-        print(errors)
 
         layer.setConstraintExpression(1, None)
 
@@ -301,7 +300,6 @@ def test_validate_attribute(self):
         res, errors = QgsVectorLayerUtils.validateAttribute(layer, f, 1)
         self.assertFalse(res)
         self.assertEqual(len(errors), 1)
-        print(errors)
 
         # checking only for provider constraints
         res, errors = QgsVectorLayerUtils.validateAttribute(layer, f, 1,
@@ -319,7 +317,6 @@ def test_validate_attribute(self):
         res, errors = QgsVectorLayerUtils.validateAttribute(layer, f, 1)
         self.assertFalse(res)
         self.assertEqual(len(errors), 1)
-        print(errors)
 
         # checking only for provider constraints
         res, errors = QgsVectorLayerUtils.validateAttribute(layer, f, 1,
@@ -354,7 +351,19 @@ def test_validate_attribute(self):
         res, errors = QgsVectorLayerUtils.validateAttribute(layer, f, 1)
         self.assertFalse(res)
         self.assertEqual(len(errors), 2)
-        print(errors)
+
+        # Test AllowMulti with no selected values, see GH #46366
+        setup = QgsEditorWidgetSetup('ValueRelation', {'AllowMulti': True})
+        layer.setEditorWidgetSetup(0, setup)
+        layer.setFieldConstraint(0, QgsFieldConstraints.ConstraintNotNull)
+        f.setAttribute(0, QVariant())
+        res, errors = QgsVectorLayerUtils.validateAttribute(layer, f, 0)
+        self.assertFalse(res)
+        f.setAttribute(0, '{}')
+        self.assertEqual(len(errors), 1)
+        res, errors = QgsVectorLayerUtils.validateAttribute(layer, f, 0)
+        self.assertFalse(res)
+        self.assertEqual(len(errors), 1)
 
     def testCreateUniqueValue(self):
         """ test creating a unique value """