[processing] Field calculator algorithms should not force an upper limit

on string field lengths

Don't hold back the algorithms because of outdated format limitations!

Author: nyalldawson

python/plugins/processing/algs/qgis/FieldPyculator.py

@@ -74,7 +74,7 @@ def initAlgorithm(self, config=None):
         self.addParameter(QgsProcessingParameterEnum(self.FIELD_TYPE,
                                                      self.tr('Field type'), options=self.type_names))
         self.addParameter(QgsProcessingParameterNumber(self.FIELD_LENGTH,
-                                                       self.tr('Field length'), minValue=1, maxValue=255,
+                                                       self.tr('Field length'), minValue=0,
                                                        defaultValue=10))
         self.addParameter(QgsProcessingParameterNumber(self.FIELD_PRECISION,
                                                        self.tr('Field precision'), minValue=0, maxValue=15,

python/plugins/processing/algs/qgis/FieldsCalculator.py

@@ -79,7 +79,7 @@ def initAlgorithm(self, config=None):
         self.addParameter(QgsProcessingParameterEnum(self.FIELD_TYPE,
                                                      self.tr('Field type'), options=self.type_names))
         self.addParameter(QgsProcessingParameterNumber(self.FIELD_LENGTH,
-                                                       self.tr('Field length'), minValue=1, maxValue=255, defaultValue=10))
+                                                       self.tr('Field length'), minValue=0, defaultValue=10))
         self.addParameter(QgsProcessingParameterNumber(self.FIELD_PRECISION,
                                                        self.tr('Field precision'), minValue=0, maxValue=15, defaultValue=3))
         self.addParameter(QgsProcessingParameterBoolean(self.NEW_FIELD,