Changes between Version 3 and Version 4 of PythonGotchas

Timestamp:

Sep 20, 2010, 9:24:58 AM (14 years ago)

Author:

jjr8

Comment:

--

PythonGotchas

@@ -107 +107 @@
 The advantage of the "Ref" and "Directly" functions is they provide faster performance because a duplicate object does not need to be created. The disadvantage is that you have to watch out for this problem.
 
-The examples above are based on [http://lists.osgeo.org/pipermail/gdal-dev/2010-September/026027.html email from Even Rouault].
+The information above is based on [http://lists.osgeo.org/pipermail/gdal-dev/2010-September/026027.html email from Even Rouault].
+
+=== Python crashes if you add a new field to an OGR layer when features deriving from this layer definition are still active ===
+
+For example:
+
+{{{
+>>> feature = lyr.GetNextFeature()
+>>> field_defn = ogr.FieldDefn("foo", ogr.OFTString)
+>>> lyr.CreateField(field_defn)                       # now, existing features deriving from this layer are invalid
+>>> feature.DumpReadable()                            # segfault
+< Python crashes >
+}}}
+
+For more information, please see #3552.
 
 === Certain objects contain a {{{Destroy()}}} method, but you should never use it ===