Fix pasting unsaved changes as temporary scratch layers

python/PyQt6/core/__init__.py.in

@@ -70,9 +70,9 @@ def _date_range_repr(self):
 QgsDateTimeRange.__repr__ = _datetime_range_repr
 QgsDateRange.__repr__ = _date_range_repr
 
-
 QgsProperty.__bool__ = lambda self: self.propertyType() != Qgis.PropertyType.Invalid
 QgsOptionalExpression.__bool__ = lambda self: self.enabled()
+QgsUnsetAttributeValue.__hash__ = lambda self: 2178310
 
 # add some __repr__ methods to processing classes
 def _processing_source_repr(self):

python/core/__init__.py.in

@@ -73,7 +73,7 @@ QgsDateRange.__repr__ = _date_range_repr
 
 QgsProperty.__bool__ = lambda self: self.propertyType() != Qgis.PropertyType.Invalid
 QgsOptionalExpression.__bool__ = lambda self: self.enabled()
-
+QgsUnsetAttributeValue.__hash__ = lambda self: 2178310
 
 # add some __repr__ methods to processing classes
 def _processing_source_repr(self):

src/core/providers/memory/qgsmemoryprovider.cpp

@@ -682,6 +682,9 @@ bool QgsMemoryProvider::changeAttributeValues( const QgsChangedAttributesMap &at
         continue;
 
       QVariant attrValue = it2.value();
+      if ( attrValue.userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+        continue;
+
       // Check attribute conversion
       const bool conversionError { ! QgsVariantUtils::isNull( attrValue )
                                    && ! mFields.at( it2.key() ).convertCompatible( attrValue, &errorMessage ) };

src/core/providers/ogr/qgsogrprovider.cpp

@@ -2763,7 +2763,7 @@ bool QgsOgrProvider::changeAttributeValues( const QgsChangedAttributesMap &attr_
     {
       useUpdate = false;
     }
-    if ( useUpdate )
+    if ( useUpdate && val.userType() != qMetaTypeId<QgsUnsetAttributeValue >() )
     {
       QString sql = QStringLiteral( "UPDATE %1 SET %2 = %3" )
                     .arg( QString::fromUtf8( QgsOgrProviderUtils::quotedIdentifier( mOgrLayer->name(), mGDALDriverName ) ) )
@@ -2838,6 +2838,9 @@ bool QgsOgrProvider::changeAttributeValues( const QgsChangedAttributesMap &attr_
     for ( QgsAttributeMap::const_iterator it2 = attr.begin(); it2 != attr.end(); ++it2 )
     {
       int f = it2.key();
+      if ( it2->userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+        continue;
+
       if ( mFirstFieldIsFid )
       {
         if ( f == 0 )

src/core/qgsfield.cpp

@@ -20,6 +20,7 @@
 #include "qgsapplication.h"
 #include "qgsreferencedgeometry.h"
 #include "qgsvariantutils.h"
+#include "qgsunsetattributevalue.h"
 
 #include <QDataStream>
 #include <QIcon>
@@ -482,6 +483,11 @@ bool QgsField::convertCompatible( QVariant &v, QString *errorMessage ) const
     return true;
   }
 
+  if ( v.userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+  {
+    return true;
+  }
+
   if ( d->type == QMetaType::Type::Int && v.toInt() != v.toLongLong() )
   {
     v = QgsVariantUtils::createNullVariant( d->type );

src/core/vector/qgsvectorlayerutils.cpp

@@ -576,7 +576,7 @@ QgsFeatureList QgsVectorLayerUtils::createFeatures( const QgsVectorLayer *layer,
         QString providerDefault = layer->dataProvider()->defaultValueClause( providerIndex );
         if ( !providerDefault.isEmpty() )
         {
-          v = providerDefault;
+          v = QgsUnsetAttributeValue( providerDefault );
           checkUnique = false;
         }
       }

src/gui/editorwidgets/qgstexteditwrapper.cpp

@@ -74,7 +74,7 @@ QVariant QgsTextEditWrapper::value() const
 
   if ( !QgsVariantUtils::isNull( defaultValue() ) && v == defaultValue().toString() )
   {
-    return defaultValue();
+    return QVariant::fromValue( QgsUnsetAttributeValue( defaultValue().toString() ) );
   }
 
   QVariant res( v );
@@ -302,6 +302,10 @@ void QgsTextEditWrapper::setWidgetValue( const QVariant &val )
   {
     v = QgsApplication::nullRepresentation();
   }
+  else if ( val.userType() == qMetaTypeId<QgsUnsetAttributeValue>() )
+  {
+    v = defaultValue().toString();
+  }
   else
   {
     v = field().displayString( val );

src/providers/hana/qgshanaprovider.cpp

@@ -748,6 +748,11 @@ bool QgsHanaProvider::addFeatures( QgsFeatureList &flist, Flags flags )
         const int fieldIndex = fieldIds[i];
         const AttributeField &field = mAttributeFields.at( fieldIndex );
         QVariant attrValue = fieldIndex < attrs.length() ? attrs.at( fieldIndex ) : QgsVariantUtils::createNullVariant( QMetaType::Type::LongLong );
+
+        // no default value clause handling supported in this provider, best we can do for now is set to NULL
+        if ( attrValue.userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+          attrValue = QVariant();
+
         if ( pkFields[i] )
         {
           hasIdValue = hasIdValue || !attrValue.isNull();
@@ -1175,6 +1180,9 @@ bool QgsHanaProvider::changeAttributeValues( const QgsChangedAttributesMap &attr
         if ( field.name.isEmpty() || field.isAutoIncrement )
           continue;
 
+        if ( it2->userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+          continue;
+
         pkChanged = pkChanged || mPrimaryKeyAttrs.contains( fieldIndex );
         auto qType = mFields.at( fieldIndex ).type();
         if ( field.type == QgsHanaDataType::Geometry && qType == QMetaType::Type::QString )
@@ -1202,7 +1210,11 @@ bool QgsHanaProvider::changeAttributeValues( const QgsChangedAttributesMap &attr
         if ( field.name.isEmpty() || field.isAutoIncrement )
           continue;
 
-        setStatementValue( stmtUpdate, paramIndex, field, *attrIt );
+        const QVariant attrValue = *attrIt;
+        if ( attrValue.userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+          continue;
+
+        setStatementValue( stmtUpdate, paramIndex, field, attrValue );
         ++paramIndex;
       }
 

src/providers/mssql/qgsmssqlprovider.cpp

@@ -1202,6 +1202,9 @@ bool QgsMssqlProvider::addFeatures( QgsFeatureList &flist, Flags flags )
       if ( fld.name().isEmpty() )
         continue; // invalid
 
+      if ( attrs.at( i ).userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+        continue;
+
       if ( mDefaultValues.contains( i ) && mDefaultValues.value( i ) == attrs.at( i ).toString() )
         continue; // skip fields having default values
 
@@ -1300,6 +1303,9 @@ bool QgsMssqlProvider::addFeatures( QgsFeatureList &flist, Flags flags )
       if ( fld.name().isEmpty() )
         continue; // invalid
 
+      if ( attrs.at( i ).userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+        continue;
+
       if ( mDefaultValues.contains( i ) && mDefaultValues.value( i ) == attrs.at( i ).toString() )
         continue; // skip fields having default values
 
@@ -1554,6 +1560,9 @@ bool QgsMssqlProvider::changeAttributeValues( const QgsChangedAttributesMap &att
       if ( fld.name().isEmpty() )
         continue; // invalid
 
+      if ( it2.value().userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+        continue;
+
       if ( mComputedColumns.contains( fld.name() ) )
         continue; // skip computed columns because they are done server side.
 
@@ -1593,6 +1602,9 @@ bool QgsMssqlProvider::changeAttributeValues( const QgsChangedAttributesMap &att
       if ( fld.name().isEmpty() )
         continue; // invalid
 
+      if ( it2.value().userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+        continue;
+
       if ( mComputedColumns.contains( fld.name() ) )
         continue; // skip computed columns because they are done server side.
 

src/providers/oracle/qgsoracleprovider.cpp

@@ -1394,10 +1394,18 @@ bool QgsOracleProvider::addFeatures( QgsFeatureList &flist, QgsFeatureSink::Flag
         QVariant value = attributevec.value( fieldId[i], QVariant() );
 
         QgsField fld = field( fieldId[i] );
-        if ( ( value.isNull() && mPrimaryKeyAttrs.contains( i ) && !defaultValues.at( i ).isEmpty() ) || ( value.toString() == defaultValues[i] ) )
+        if ( ( QgsVariantUtils::isNull( value ) && mPrimaryKeyAttrs.contains( i ) && !defaultValues.at( i ).isEmpty() )
+             || ( value.toString() == defaultValues[i] )
+             || value.userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
         {
           value = evaluateDefaultExpression( defaultValues[i], fld.type() );
         }
+        else if ( QgsVariantUtils::isNull( value ) )
+        {
+          // don't use typed null variants, always use invalid variants. Otherwise the connection
+          // may incorrectly try to coerce a null value to the variant type
+          value = QVariant();
+        }
         features->setAttribute( fieldId[i], value );
 
         QgsDebugMsgLevel( QStringLiteral( "addBindValue: %1" ).arg( value.toString() ), 4 );
@@ -1854,6 +1862,10 @@ bool QgsOracleProvider::changeAttributeValues( const QgsChangedAttributesMap &at
             QgsLogger::warning( tr( "Changing the value of GENERATED field %1 is not allowed." ).arg( fld.name() ) );
             continue;
           }
+          if ( siter.value().userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+          {
+            continue;
+          }
 
           pkChanged = pkChanged || mPrimaryKeyAttrs.contains( siter.key() );
 

src/providers/postgres/qgspostgresprovider.cpp

@@ -2287,7 +2287,7 @@ bool QgsPostgresProvider::addFeatures( QgsFeatureList &flist, Flags flags )
           QVariant v2 = attrs2.value( idx, QgsVariantUtils::createNullVariant( QMetaType::Type::Int ) );
           // a PK field with a sequence val is auto populate by QGIS with this default
           // we are only interested in non default values
-          if ( !QgsVariantUtils::isNull( v2 ) && v2.toString() != defaultValue )
+          if ( !QgsVariantUtils::isNull( v2 ) && v2.toString() != defaultValue && v2.userType() != qMetaTypeId< QgsUnsetAttributeValue >() )
           {
             foundNonEmptyPK = true;
             break;
@@ -2298,7 +2298,7 @@ bool QgsPostgresProvider::addFeatures( QgsFeatureList &flist, Flags flags )
 
       if ( !skipSinglePKField )
       {
-        for ( int idx : mPrimaryKeyAttrs )
+        for ( int idx : std::as_const( mPrimaryKeyAttrs ) )
         {
           if ( mIdentityFields[idx] == 'a' )
             overrideIdentity = true;
@@ -2327,7 +2327,6 @@ bool QgsPostgresProvider::addFeatures( QgsFeatureList &flist, Flags flags )
         continue;
 
       QString fieldname = mAttributeFields.at( idx ).name();
-
       if ( !mGeneratedValues.value( idx, QString() ).isEmpty() )
       {
         QgsDebugMsgLevel( QStringLiteral( "Skipping field %1 (idx %2) which is GENERATED." ).arg( fieldname, QString::number( idx ) ), 2 );
@@ -2469,7 +2468,7 @@ bool QgsPostgresProvider::addFeatures( QgsFeatureList &flist, Flags flags )
         QVariant value = attrIdx < attrs.length() ? attrs.at( attrIdx ) : QgsVariantUtils::createNullVariant( QMetaType::Type::Int );
 
         QString v;
-        if ( QgsVariantUtils::isNull( value ) )
+        if ( QgsVariantUtils::isNull( value ) || value.userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
         {
           QgsField fld = field( attrIdx );
           v = paramValue( defaultValues[i], defaultValues[i] );
@@ -2949,6 +2948,10 @@ bool QgsPostgresProvider::changeAttributeValues( const QgsChangedAttributesMap &
       {
         try
         {
+          const QVariant attributeValue = siter.value();
+          if ( attributeValue.userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+            continue;
+
           QgsField fld = field( siter.key() );
 
           pkChanged = pkChanged || mPrimaryKeyAttrs.contains( siter.key() );
@@ -2965,39 +2968,39 @@ bool QgsPostgresProvider::changeAttributeValues( const QgsChangedAttributesMap &
           delim = ',';
 
           QString defVal = defaultValueClause( siter.key() );
-          if ( qgsVariantEqual( *siter, defVal ) )
+          if ( qgsVariantEqual( attributeValue, defVal ) )
           {
             sql += defVal.isNull() ? "NULL" : defVal;
           }
           else if ( fld.typeName() == QLatin1String( "geometry" ) )
           {
-            QString val = geomAttrToString( siter.value(), connectionRO() );
+            QString val = geomAttrToString( attributeValue, connectionRO() );
 
             sql += QStringLiteral( "%1(%2)" )
                      .arg( connectionRO()->majorVersion() < 2 ? "geomfromewkt" : "st_geomfromewkt", quotedValue( val ) );
           }
           else if ( fld.typeName() == QLatin1String( "geography" ) )
           {
             sql += QStringLiteral( "st_geographyfromtext(%1)" )
-                     .arg( quotedValue( siter->toString() ) );
+                     .arg( quotedValue( attributeValue.toString() ) );
           }
           else if ( fld.typeName() == QLatin1String( "jsonb" ) )
           {
             sql += QStringLiteral( "%1::jsonb" )
-                     .arg( quotedJsonValue( siter.value() ) );
+                     .arg( quotedJsonValue( attributeValue ) );
           }
           else if ( fld.typeName() == QLatin1String( "json" ) )
           {
             sql += QStringLiteral( "%1::json" )
-                     .arg( quotedJsonValue( siter.value() ) );
+                     .arg( quotedJsonValue( attributeValue ) );
           }
           else if ( fld.typeName() == QLatin1String( "bytea" ) )
           {
-            sql += quotedByteaValue( siter.value() );
+            sql += quotedByteaValue( attributeValue );
           }
           else
           {
-            sql += quotedValue( *siter );
+            sql += quotedValue( attributeValue );
           }
         }
         catch ( PGFieldNotFound )
@@ -3328,39 +3331,45 @@ bool QgsPostgresProvider::changeFeatures( const QgsChangedAttributesMap &attr_ma
             continue;
           }
 
+          const QVariant value = siter.value();
+          if ( value.userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+          {
+            continue;
+          }
+
           numChangedFields++;
 
           sql += delim + QStringLiteral( "%1=" ).arg( quotedIdentifier( fld.name() ) );
           delim = ',';
 
           if ( fld.typeName() == QLatin1String( "geometry" ) )
           {
-            QString val = geomAttrToString( siter.value(), connectionRO() );
+            QString val = geomAttrToString( value, connectionRO() );
             sql += QStringLiteral( "%1(%2)" )
                      .arg( connectionRO()->majorVersion() < 2 ? "geomfromewkt" : "st_geomfromewkt", quotedValue( val ) );
           }
           else if ( fld.typeName() == QLatin1String( "geography" ) )
           {
             sql += QStringLiteral( "st_geographyfromtext(%1)" )
-                     .arg( quotedValue( siter->toString() ) );
+                     .arg( quotedValue( value.toString() ) );
           }
           else if ( fld.typeName() == QLatin1String( "jsonb" ) )
           {
             sql += QStringLiteral( "%1::jsonb" )
-                     .arg( quotedJsonValue( siter.value() ) );
+                     .arg( quotedJsonValue( value ) );
           }
           else if ( fld.typeName() == QLatin1String( "json" ) )
           {
             sql += QStringLiteral( "%1::json" )
-                     .arg( quotedJsonValue( siter.value() ) );
+                     .arg( quotedJsonValue( value ) );
           }
           else if ( fld.typeName() == QLatin1String( "bytea" ) )
           {
-            sql += quotedByteaValue( siter.value() );
+            sql += quotedByteaValue( value );
           }
           else
           {
-            sql += quotedValue( *siter );
+            sql += quotedValue( value );
           }
         }
         catch ( PGFieldNotFound )

src/providers/spatialite/qgsspatialiteprovider.cpp

@@ -4131,7 +4131,10 @@ bool QgsSpatiaLiteProvider::addFeatures( QgsFeatureList &flist, Flags flags )
 
       for ( int i = 0; i < attributevec.count(); ++i )
       {
-        if ( mDefaultValues.contains( i ) && ( mDefaultValues.value( i ) == attributevec.at( i ).toString() || !attributevec.at( i ).isValid() ) )
+        if (
+          ( mDefaultValues.contains( i ) && ( mDefaultValues.value( i ) == attributevec.at( i ).toString() || !attributevec.at( i ).isValid() ) )
+          || ( attributevec.at( i ).userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+        )
         {
           defaultIndexes.push_back( i );
           continue;
@@ -4597,6 +4600,8 @@ bool QgsSpatiaLiteProvider::changeAttributeValues( const QgsChangedAttributesMap
       {
         QgsField fld = field( siter.key() );
         const QVariant &val = siter.value();
+        if ( val.userType() == qMetaTypeId< QgsUnsetAttributeValue >() )
+          continue;
 
         if ( !first )
           sql += ',';

tests/src/core/testqgsfield.cpp

@@ -26,6 +26,7 @@
 #include "qgsapplication.h"
 #include "qgstest.h"
 #include "qgsreferencedgeometry.h"
+#include "qgsunsetattributevalue.h"
 
 class TestQgsField : public QObject
 {
@@ -603,6 +604,9 @@ void TestQgsField::convertCompatible()
   QVERIFY( stringField.convertCompatible( nullDouble ) );
   QCOMPARE( static_cast<QMetaType::Type>( nullDouble.userType() ), QMetaType::Type::QString );
   QVERIFY( nullDouble.isNull() );
+  QVariant unsetValue = QgsUnsetAttributeValue( QStringLiteral( "Autonumber" ) );
+  QVERIFY( stringField.convertCompatible( unsetValue ) );
+  QCOMPARE( static_cast<QMetaType::Type>( unsetValue.userType() ), qMetaTypeId< QgsUnsetAttributeValue >() );
 
   //test double
   const QgsField doubleField( QStringLiteral( "double" ), QMetaType::Type::Double, QStringLiteral( "double" ) );
@@ -636,6 +640,9 @@ void TestQgsField::convertCompatible()
   QVERIFY( doubleField.convertCompatible( nullDouble ) );
   QCOMPARE( static_cast<QMetaType::Type>( nullDouble.userType() ), QMetaType::Type::Double );
   QVERIFY( nullDouble.isNull() );
+  unsetValue = QgsUnsetAttributeValue( QStringLiteral( "Autonumber" ) );
+  QVERIFY( doubleField.convertCompatible( unsetValue ) );
+  QCOMPARE( static_cast<QMetaType::Type>( unsetValue.userType() ), qMetaTypeId< QgsUnsetAttributeValue >() );
 
   //test special rules