Fixes #45198 : Don't return default value when null

qgis · Sep 28, 2021 · 3a29522 · 3a29522
1 parent 7824b3d
commit 3a29522
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Showing 2 changed files with 42 additions and 3 deletions.
diff --git a/src/core/qgsfieldformatter.cpp b/src/core/qgsfieldformatter.cpp
@@ -19,7 +19,7 @@
 #include "qgsfields.h"
 #include "qgsvectorlayer.h"
 #include "qgsvectordataprovider.h"
-
+#include "qgsapplication.h"
 
 QString QgsFieldFormatter::representValue( QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value ) const
 {
@@ -30,13 +30,17 @@ QString QgsFieldFormatter::representValue( QgsVectorLayer *layer, int fieldIndex
   if ( layer->fields().fieldOrigin( fieldIndex ) == QgsFields::OriginProvider && layer->dataProvider() )
     defVal = layer->dataProvider()->defaultValueClause( layer->fields().fieldOriginIndex( fieldIndex ) );
 
-  if ( ! layer->fields().exists( fieldIndex ) )
+  if ( !defVal.isNull() && defVal == value )
   {
     return defVal;
   }
+  else if ( value.isNull() )
+  {
+    return QgsApplication::nullRepresentation();
+  }
   else
   {
-    return layer->fields().at( fieldIndex ).displayString( value.isNull() ? defVal : value );
+    return layer->fields().at( fieldIndex ).displayString( value );
   }
 }
 

diff --git a/tests/src/python/test_qgsfieldformatters.py b/tests/src/python/test_qgsfieldformatters.py
@@ -12,6 +12,7 @@
 
 
 import tempfile
+import os
 
 import qgis  # NOQA
 
@@ -23,6 +24,7 @@
 
 from qgis.PyQt.QtCore import QCoreApplication, QLocale, QVariant
 from qgis.testing import start_app, unittest
+from qgis.utils import spatialite_connect
 from utilities import writeShape
 
 start_app()
@@ -599,6 +601,39 @@ def _test(layer, is_gpkg=False):
         # No precision here
         _test(gpkg_layer, True)
 
+    def test_representValueWithDefault(self):
+        """
+        Check representValue behaves correctly when used on a layer which define default values
+        """
+
+        dbname = os.path.join(tempfile.mkdtemp(), 'test.sqlite')
+        con = spatialite_connect(dbname, isolation_level=None)
+        cur = con.cursor()
+        cur.execute("BEGIN")
+        sql = """
+        CREATE TABLE test_table_default_values (
+            id integer primary key autoincrement,
+            anumber INTEGER DEFAULT 123
+        )
+        """
+        cur.execute(sql)
+        cur.execute("COMMIT")
+        con.close()
+
+        vl = QgsVectorLayer(dbname + '|layername=test_table_default_values', 'test_table_default_values', 'ogr')
+        self.assertTrue(vl.isValid())
+
+        fieldFormatter = QgsFallbackFieldFormatter()
+
+        QLocale.setDefault(QLocale('en'))
+
+        self.assertEqual(fieldFormatter.representValue(vl, 1, {}, None, QVariant(QVariant.Int)),
+                         'NULL')
+        self.assertEqual(fieldFormatter.representValue(vl, 1, {}, None, 4),
+                         '4')
+        self.assertEqual(fieldFormatter.representValue(vl, 1, {}, None, "123"),
+                         '123')
+
 
 if __name__ == '__main__':
     unittest.main()