Fix spatialite provider for Null QVariant instead of Invalid QVariant

Author: m-kuhn

src/core/qgsvectordataprovider.cpp

@@ -396,8 +396,8 @@ QVariant QgsVectorDataProvider::convertValue( QVariant::Type type, QString value
 {
   QVariant v( value );
 
-  if ( !v.convert( type ) )
-    v = QVariant( QString::null );
+  if ( !v.convert( type ) || value.isNull() )
+    v = QVariant( type );
 
   return v;
 }

src/providers/spatialite/qgsspatialiteprovider.cpp

@@ -3270,7 +3270,7 @@ QString QgsSpatiaLiteProvider::description() const
   return SPATIALITE_DESCRIPTION;
 }                               //  QgsSpatiaLiteProvider::description()
 
-const QgsFields & QgsSpatiaLiteProvider::fields() const
+const QgsFields& QgsSpatiaLiteProvider::fields() const
 {
   return attributeFields;
 }
@@ -3290,7 +3290,7 @@ QVariant QgsSpatiaLiteProvider::minimumValue( int index )
   try
   {
     // get the field name
-    const QgsField & fld = field( index );
+    const QgsField& fld = field( index );
 
     sql = QString( "SELECT Min(%1) FROM %2" ).arg( quotedIdentifier( fld.name() ) ).arg( mQuery );
 
@@ -3301,41 +3301,44 @@ QVariant QgsSpatiaLiteProvider::minimumValue( int index )
 
     ret = sqlite3_get_table( sqliteHandle, sql.toUtf8().constData(), &results, &rows, &columns, &errMsg );
     if ( ret != SQLITE_OK )
-      goto error;
-    if ( rows < 1 )
-      ;
-    else
     {
-      for ( i = 1; i <= rows; i++ )
+      QgsMessageLog::logMessage( tr( "SQLite error: %2\nSQL: %1" ).arg( sql ).arg( errMsg ? errMsg : tr( "unknown cause" ) ), tr( "SpatiaLite" ) );
+      // unexpected error
+      if ( errMsg != NULL )
       {
-        minValue = results[( i * columns ) + 0];
+        sqlite3_free( errMsg );
       }
-    }
-    sqlite3_free_table( results );
-
-    if ( minValue.isEmpty() )
-    {
-      // NULL or not found
-      return QVariant( QString::null );
+      minValue = QString();
     }
     else
     {
-      return convertValue( fld.type(), minValue );
+      if ( rows < 1 )
+        ;
+      else
+      {
+        for ( i = 1; i <= rows; i++ )
+        {
+          minValue = results[( i * columns ) + 0];
+        }
+      }
+      sqlite3_free_table( results );
+
+      if ( minValue.isEmpty() )
+      {
+        // NULL or not found
+        minValue = QString();
+      }
     }
+
+    return convertValue( fld.type(), minValue );
   }
   catch ( SLFieldNotFound )
   {
-    return QVariant( QString::null );
+    return QVariant( QVariant::Int );
   }
 
-error:
-  QgsMessageLog::logMessage( tr( "SQLite error: %2\nSQL: %1" ).arg( sql ).arg( errMsg ? errMsg : tr( "unknown cause" ) ), tr( "SpatiaLite" ) );
-  // unexpected error
-  if ( errMsg != NULL )
-  {
-    sqlite3_free( errMsg );
-  }
-  return QVariant( QString::null );
+  // dummy return, so compiler is quiet
+  return QVariant();
 }
 
 // Returns the maximum value of an attribute
@@ -3364,41 +3367,45 @@ QVariant QgsSpatiaLiteProvider::maximumValue( int index )
 
     ret = sqlite3_get_table( sqliteHandle, sql.toUtf8().constData(), &results, &rows, &columns, &errMsg );
     if ( ret != SQLITE_OK )
-      goto error;
-    if ( rows < 1 )
-      ;
-    else
     {
-      for ( i = 1; i <= rows; i++ )
+      QgsMessageLog::logMessage( tr( "SQLite error: %2\nSQL: %1" ).arg( sql ).arg( errMsg ? errMsg : tr( "unknown cause" ) ), tr( "SpatiaLite" ) );
+      // unexpected error
+      if ( errMsg != NULL )
       {
-        maxValue = results[( i * columns ) + 0];
+        sqlite3_free( errMsg );
       }
-    }
-    sqlite3_free_table( results );
-
-    if ( maxValue.isEmpty() )
-    {
-      // NULL or not found
-      return QVariant( QString::null );
+      maxValue = QString();
     }
     else
     {
-      return convertValue( fld.type(), maxValue );
+
+      if ( rows < 1 )
+        ;
+      else
+      {
+        for ( i = 1; i <= rows; i++ )
+        {
+          maxValue = results[( i * columns ) + 0];
+        }
+      }
+      sqlite3_free_table( results );
+
+      if ( maxValue.isEmpty() )
+      {
+        // NULL or not found
+        maxValue = QString();
+      }
     }
+
+    return convertValue( fld.type(), maxValue );
   }
   catch ( SLFieldNotFound )
   {
-    return QVariant( QString::null );
+    return QVariant( QVariant::Int );
   }
 
-error:
-  QgsMessageLog::logMessage( tr( "SQLite error: %2\nSQL: %1" ).arg( sql ).arg( errMsg ? errMsg : tr( "unknown cause" ) ), tr( "SpatiaLite" ) );
-  // unexpected error
-  if ( errMsg != NULL )
-  {
-    sqlite3_free( errMsg );
-  }
-  return QVariant( QString::null );
+  // dummy return, so compiler is quiet
+  return QVariant();
 }
 
 // Returns the list of unique values of an attribute
@@ -3565,7 +3572,7 @@ bool QgsSpatiaLiteProvider::addFeatures( QgsFeatureList & flist )
 
   for ( int i = 0; i < attributevec.count(); ++i )
   {
-    if ( !attributevec[i].isValid() )
+    if ( !attributevec[i].isNull() )
       continue;
 
     if ( i >= attributeFields.count() )
@@ -3594,7 +3601,7 @@ bool QgsSpatiaLiteProvider::addFeatures( QgsFeatureList & flist )
   for ( QgsFeatureList::iterator features = flist.begin(); features != flist.end(); features++ )
   {
     // looping on each feature to insert
-    const QgsAttributes & attributevec = features->attributes();
+    const QgsAttributes& attributevec = features->attributes();
 
     // resetting Prepared Statement and bindings
     sqlite3_reset( stmt );
@@ -3627,23 +3634,18 @@ bool QgsSpatiaLiteProvider::addFeatures( QgsFeatureList & flist )
     for ( int i = 0; i < attributevec.count(); ++i )
     {
       QVariant v = attributevec[i];
-      if ( !v.isValid() )
+      if ( !v.isNull() )
         continue;
 
       // binding values for each attribute
       if ( i >= attributeFields.count() )
-        continue;
+        break;
 
       QString fieldname = attributeFields[i].name();
       if ( fieldname.isEmpty() || fieldname == mGeometryColumn )
         continue;
 
       QVariant::Type type = attributeFields[i].type();
-      if ( v.toString().isEmpty() )
-      {
-        // assuming to be a NULL value
-        type = QVariant::Invalid;
-      }
 
       if ( type == QVariant::Int )
       {