From 273e0f0b71f852ed8edb1b3a749134680d033756 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Rheinl=C3=A4nder?=
 <jrheinlaender@users.sourceforge.net>
Date: Wed, 4 Dec 2013 20:40:37 +0100
Subject: [PATCH] Fixed bug that did not allow selecting datum planes as
 external references in sketches

---
 src/Mod/Sketcher/App/SketchObject.cpp     | 5 +++--
 src/Mod/Sketcher/Gui/CommandCreateGeo.cpp | 9 ++++++---
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/Mod/Sketcher/App/SketchObject.cpp b/src/Mod/Sketcher/App/SketchObject.cpp
index 74344feba..d156b8032 100644
--- a/src/Mod/Sketcher/App/SketchObject.cpp
+++ b/src/Mod/Sketcher/App/SketchObject.cpp
@@ -1707,10 +1707,11 @@ bool SketchObject::isExternalAllowed(App::Document *pDoc, App::DocumentObject *p
 {
     // Externals outside of the Document are NOT allowed
     if (this->getDocument() != pDoc)
-        return false;
+        return false;    
 
+    // Note: Checking for the body of the support doesn't work when the support are the three base planes
     App::DocumentObject *support = this->Support.getValue();
-    Part::BodyBase* body = Part::BodyBase::findBodyOf(support);
+    Part::BodyBase* body = Part::BodyBase::findBodyOf(this);
     if (body != NULL) {
         if (Part::BodyBase::findBodyOf(pObj) != body) {
             // Selection outside of body not allowed if flag is not set
diff --git a/src/Mod/Sketcher/Gui/CommandCreateGeo.cpp b/src/Mod/Sketcher/Gui/CommandCreateGeo.cpp
index 067c3069e..75714e31d 100644
--- a/src/Mod/Sketcher/Gui/CommandCreateGeo.cpp
+++ b/src/Mod/Sketcher/Gui/CommandCreateGeo.cpp
@@ -4478,8 +4478,8 @@ namespace SketcherGui {
             if (!sketch->isExternalAllowed(pDoc, pObj))
                 return false;
 
-            App::DocumentObject *support = sketch->Support.getValue();
-            Part::BodyBase* body = Part::BodyBase::findBodyOf(support);
+            // Note: its better to search the support of the sketch in case the sketch support is a base plane
+            Part::BodyBase* body = Part::BodyBase::findBodyOf(sketch);
             if ((body != NULL) && (Part::BodyBase::findBodyOf(pObj) == body) && body->isAfterTip(pObj))
                 // Don't allow selection after the Tip feature in the same body
                 return false;
@@ -4491,7 +4491,10 @@ namespace SketcherGui {
                 (element.size() > 6 && element.substr(0,6) == "Vertex") ||
                 (element.size() > 4 && element.substr(0,4) == "Face")) {
                 return true;
-            }
+            }            
+            if (pObj->getTypeId().isDerivedFrom(App::Plane::getClassTypeId()) ||
+                pObj->getTypeId().isDerivedFrom(Part::Datum::getClassTypeId()))
+                return true;
             return  false;
         }
     };