From dc860f75ed039981db5a916dfae9f2918111be2c Mon Sep 17 00:00:00 2001
From: Matthias Kuhn <matthias.kuhn@gmx.ch>
Date: Wed, 5 Jun 2013 11:59:50 +0200
Subject: [PATCH] When calling setFields, automatically initalize attributes
 That what you want most of the time when creating a new feature within a
 plugin. Therefore defaults to true when used from python, but to false when
 used from C++

---
 python/core/qgsfeature.sip | 11 +++++++++--
 src/core/qgsfeature.cpp    |  9 +++++++++
 src/core/qgsfeature.h      | 11 ++++++++++-
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/python/core/qgsfeature.sip b/python/core/qgsfeature.sip
index 94755a5a2d5..14558565bd3 100644
--- a/python/core/qgsfeature.sip
+++ b/python/core/qgsfeature.sip
@@ -158,10 +158,17 @@ class QgsFeature
      */
     void setGeometryAndOwnership( unsigned char * geom /Transfer/, size_t length );
 
-    /** Assign a field map with the feature to allow attribute access by attribute name
+    /** Assign a field map with the feature to allow attribute access by
+     * attribute name
+     *
+     *  @param fields         The attribute fields which this feature holds
+     *  @param initAttributes If true, attributes are initialized. Clears any
+     *  data previously assigned.
+     *                        C++: Defaults to false
+     *                        Python: Defaults to true
      *  @note added in 2.0
      */
-    void setFields( const QgsFields* fields );
+    void setFields( const QgsFields* fields, bool initAttributes = true );
 
     /** Get associated field map. may be NULL
      *  @note added in 2.0
diff --git a/src/core/qgsfeature.cpp b/src/core/qgsfeature.cpp
index bda531ed398..513c60a5a32 100644
--- a/src/core/qgsfeature.cpp
+++ b/src/core/qgsfeature.cpp
@@ -159,6 +159,15 @@ void QgsFeature::setGeometryAndOwnership( unsigned char *geom, size_t length )
   setGeometry( g );
 }
 
+void QgsFeature::setFields( const QgsFields* fields, bool initAttributes )
+{
+  mFields = fields;
+  if ( initAttributes )
+  {
+    this->initAttributes( fields->count() );
+  }
+}
+
 
 bool QgsFeature::isValid() const
 {
diff --git a/src/core/qgsfeature.h b/src/core/qgsfeature.h
index 705b0d0c4a4..6a7576a4d76 100644
--- a/src/core/qgsfeature.h
+++ b/src/core/qgsfeature.h
@@ -189,9 +189,18 @@ class CORE_EXPORT QgsFeature
     void setGeometryAndOwnership( unsigned char * geom, size_t length );
 
     /** Assign a field map with the feature to allow attribute access by attribute name
+     *
+     *  @param fields         The attribute fields which this feature holds. When used from python, make sure
+     *                        a copy of the fields is held by python, as ownership stays there.
+     *                        I.e. Do not call feature.setFields( myDataProvider.fields() ) but instead call
+     *                        myFields = myDataProvider.fields()
+     *                        feature.setFields( myFields )
+     *  @param initAttributes If true, attributes are initialized. Clears any data previously assigned.
+     *                        C++: Defaults to false
+     *                        Python: Defaults to true
      *  @note added in 2.0
      */
-    void setFields( const QgsFields* fields ) { mFields = fields; }
+    void setFields( const QgsFields* fields, bool initAttributes = false );
 
     /** Get associated field map. may be NULL
      *  @note added in 2.0