[processing] Fix crash in extract by attribute when field name does n…

…ot exist Fixes #19531
qgis · Aug 3, 2018 · 4acef1e · 4acef1e
1 parent 9e08606
commit 4acef1e
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Showing 5 changed files with 23 additions and 1 deletion.
diff --git a/python/plugins/processing/algs/qgis/SelectByAttribute.py b/python/plugins/processing/algs/qgis/SelectByAttribute.py
@@ -130,6 +130,9 @@ def processAlgorithm(self, parameters, context, feedback):
         fields = layer.fields()
 
         idx = layer.fields().lookupField(fieldName)
+        if idx < 0:
+            raise QgsProcessingException(self.tr("Field '{}' was not found in layer").format(fieldName))
+
         fieldType = fields[idx].type()
 
         if fieldType != QVariant.String and operator in self.STRING_OPERATORS:

diff --git a/python/plugins/processing/tests/AlgorithmsTestBase.py b/python/plugins/processing/tests/AlgorithmsTestBase.py
@@ -119,6 +119,9 @@ def check_algorithm(self, name, defs):
             exec(('\n'.join(defs['expectedFailure'][:-1])), globals(), locals())
             expectFailure = eval(defs['expectedFailure'][-1])
 
+        if 'expectedException' in defs:
+            expectFailure = True
+
         # ignore user setting for invalid geometry handling
         context = QgsProcessingContext()
         context.setProject(QgsProject.instance())

diff --git a/python/plugins/processing/tests/testdata/custom/circular_strings.gpkg b/python/plugins/processing/tests/testdata/custom/circular_strings.gpkg
diff --git a/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml b/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml
@@ -2086,6 +2086,20 @@ tests:
         name: expected/extract_by_attribute_not_null.gml
         type: vector
 
+  - algorithm: native:extractbyattribute
+    name: Extract by attribute (bad field)
+    params:
+      FIELD: notafield
+      INPUT:
+        name: polys.gml
+        type: vector
+      OPERATOR: '9'
+    results:
+      OUTPUT:
+        name: expected/failure.gml
+        type: vector
+    expectedException: true
+
   - algorithm: native:extractbyattribute
     name: Extract by attribute (starts with)
     params:

diff --git a/src/analysis/processing/qgsalgorithmextractbyattribute.cpp b/src/analysis/processing/qgsalgorithmextractbyattribute.cpp
@@ -101,8 +101,10 @@ QVariantMap QgsExtractByAttributeAlgorithm::processAlgorithm( const QVariantMap
   std::unique_ptr< QgsFeatureSink > nonMatchingSink( parameterAsSink( parameters, QStringLiteral( "FAIL_OUTPUT" ), context, nonMatchingSinkId, source->fields(),
       source->wkbType(), source->sourceCrs() ) );
 
-
   int idx = source->fields().lookupField( fieldName );
+  if ( idx < 0 )
+    throw QgsProcessingException( QObject::tr( "Field '%1' was not found in INPUT source" ).arg( fieldName ) );
+
   QVariant::Type fieldType = source->fields().at( idx ).type();
 
   if ( fieldType != QVariant::String && ( op == BeginsWith || op == Contains || op == DoesNotContain ) )