Python exceptions for invalid keys in QgsFields methods (fix #13221)

python/core/qgsfield.sip

@@ -215,6 +215,18 @@ class QgsFields
     bool appendExpressionField( const QgsField& field, int originIndex );
     //! Remove a field with the given index
     void remove( int fieldIdx );
+%MethodCode
+  if ( a0 < 0 || a0 >= sipCpp->count() )
+  {
+    PyErr_SetString(PyExc_KeyError, QByteArray::number(a0));
+    sipIsErr = 1;
+  }
+  else
+  {
+    sipCpp->remove( a0 );
+  }
+%End
+
     //! Extend with fields from another QgsFields container
     void extend( const QgsFields& other );
 
@@ -244,19 +256,78 @@ class QgsFields
     sipIsErr = 1;
   else
     sipRes = new QgsField(sipCpp->operator[](idx));
-
 %End
+
     //! Get field at particular index (must be in range 0..N-1)
-    const QgsField& at( int i ) const;
+    const QgsField& at( int i ) const /Factory/;
+%MethodCode
+  if ( a0 < 0 || a0 >= sipCpp->count() )
+  {
+    PyErr_SetString(PyExc_KeyError, QByteArray::number(a0));
+    sipIsErr = 1;
+  }
+  else
+  {
+    sipRes = new QgsField( sipCpp->at( a0 ) );
+  }
+%End
+
     //! Get field at particular index (must be in range 0..N-1)
-    const QgsField& field( int fieldIdx ) const;
+    const QgsField& field( int fieldIdx ) const /Factory/;
+%MethodCode
+  if ( a0 < 0 || a0 >= sipCpp->count() )
+  {
+    PyErr_SetString(PyExc_KeyError, QByteArray::number(a0));
+    sipIsErr = 1;
+  }
+  else
+  {
+    sipRes = new QgsField( sipCpp->field( a0 ) );
+  }
+%End
+
     //! Get field at particular index (must be in range 0..N-1)
-    const QgsField& field( const QString& name ) const;
+    const QgsField& field( const QString& name ) const /Factory/;
+%MethodCode
+  int fieldIdx = sipCpp->indexFromName(*a0);
+  if (fieldIdx == -1)
+  {
+    PyErr_SetString(PyExc_KeyError, a0->toAscii());
+    sipIsErr = 1;
+  }
+  else
+  {
+    sipRes = new QgsField( sipCpp->field( *a0 ) );
+  }
+%End
 
     //! Get field's origin (value from an enumeration)
     FieldOrigin fieldOrigin( int fieldIdx ) const;
+%MethodCode
+  if ( a0 < 0 || a0 >= sipCpp->count() )
+  {
+    PyErr_SetString(PyExc_KeyError, QByteArray::number(a0));
+    sipIsErr = 1;
+  }
+  else
+  {
+    sipRes = sipCpp->fieldOrigin( a0 );
+  }
+%End
+
     //! Get field's origin index (its meaning is specific to each type of origin)
     int fieldOriginIndex( int fieldIdx ) const;
+%MethodCode
+  if ( a0 < 0 || a0 >= sipCpp->count() )
+  {
+    PyErr_SetString(PyExc_KeyError, QByteArray::number(a0));
+    sipIsErr = 1;
+  }
+  else
+  {
+    sipRes = sipCpp->fieldOriginIndex( a0 );
+  }
+%End
 
     //! Look up field's index from name. Returns -1 on error
     int indexFromName( const QString& name ) const;

tests/src/python/CMakeLists.txt

@@ -53,6 +53,7 @@ ADD_PYTHON_TEST(PyQgsShapefileProvider test_provider_shapefile.py)
 ADD_PYTHON_TEST(PyQgsMemoryProvider test_provider_memory.py)
 ADD_PYTHON_TEST(PyQgsVectorColorRamp test_qgsvectorcolorramp.py)
 ADD_PYTHON_TEST(PyQgsSyntacticSugar test_syntactic_sugar.py)
+ADD_PYTHON_TEST(PyQgsField test_qgsfield.py)
 
 IF (NOT WIN32)
   ADD_PYTHON_TEST(PyQgsLogger test_qgslogger.py)

tests/src/python/test_qgsfield.py

@@ -0,0 +1,84 @@
+# -*- coding: utf-8 -*-
+"""QGIS Unit tests for QgsField.
+
+.. note:: This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+"""
+__author__ = 'Nyall Dawson'
+__date__ = '16/08/2015'
+__copyright__ = 'Copyright 2015, The QGIS Project'
+# This will get replaced with a git SHA1 when you do a git archive
+__revision__ = '$Format:%H$'
+
+import qgis
+import os
+
+from qgis.core import QgsField, QgsVectorLayer, NULL
+from utilities import (unitTestDataPath,
+                       getQgisTestApp,
+                       TestCase,
+                       unittest
+                       )
+from unittest import expectedFailure
+
+QGISAPP, CANVAS, IFACE, PARENT = getQgisTestApp()
+
+class TestQgsFields(TestCase):
+
+    def test_expections(self):
+        ml=QgsVectorLayer("Point?crs=epsg:4236&field=id:integer&field=value:double",
+                          "test_data", "memory")
+        assert ml.isValid()
+        fields=ml.fields()
+
+        #check no error
+        fields.remove(1)
+        #check exceptions raised
+        with self.assertRaises(KeyError):
+            fields.remove(-1)
+        with self.assertRaises(KeyError):
+            fields.remove(111)
+
+        fields=ml.fields()
+        #check no error
+        fields.at(1)
+        #check exceptions raised
+        with self.assertRaises(KeyError):
+            fields.at(-1)
+        with self.assertRaises(KeyError):
+            fields.at(111)
+
+        #check no error
+        fields.field(1)
+        #check exceptions raised
+        with self.assertRaises(KeyError):
+            fields.field(-1)
+        with self.assertRaises(KeyError):
+            fields.field(111)
+
+        #check no error
+        fields.field('value')
+        #check exceptions raised
+        with self.assertRaises(KeyError):
+            fields.field('bad')
+
+        #check no error
+        fields.fieldOrigin(1)
+        #check exceptions raised
+        with self.assertRaises(KeyError):
+            fields.fieldOrigin(-1)
+        with self.assertRaises(KeyError):
+            fields.fieldOrigin(111)
+
+        #check no error
+        fields.fieldOriginIndex(1)
+        #check exceptions raised
+        with self.assertRaises(KeyError):
+            fields.fieldOriginIndex(-1)
+        with self.assertRaises(KeyError):
+            fields.fieldOriginIndex(111)
+
+if __name__ == '__main__':
+    unittest.main()