Patch #8344:

Submitted by: Thomas Knight (epat)

Parts committed:
1) Fixed a few misspellings in some error strings.
2) Fixed a (theoretical) bug with pyconstraints where a text object could be deleted from python but would remain linked
to the constraint it was assigned to - causing slight UI usage discontinuities!

Not committed yet:
3) Particle system bugfix in this patch has not been committed. Could jahka or brecht check this.

source/blender/python/BPY_extern.h

@@ -79,6 +79,7 @@ extern "C" {
 	void BPY_pyconstraint_target(struct bPythonConstraint *con, struct bConstraintTarget *ct);
 	void BPY_pyconstraint_update(struct Object *owner, struct bConstraint *con);
 	int BPY_is_pyconstraint(struct Text *text);
+	void BPY_free_pyconstraint_links(struct Text *text);
 	
 	void BPY_start_python( int argc, char **argv );
 	void BPY_end_python( void );

source/blender/python/BPY_interface.c

@@ -1261,6 +1261,45 @@ int BPY_is_pyconstraint(Text *text)
 	return 0;
 }
 
+/* This function frees links from pyconstraints to a given text-buffer.
+ * Used when a text-buffer is unlinked!
+ */
+void BPY_free_pyconstraint_links(Text *text)
+{
+	Object *ob;
+	bConstraint *con;
+	short update;
+	
+	/*check all pyconstraints*/
+	for (ob=G.main->object.first; ob; ob=ob->id.next) {
+		update = 0;
+		if(ob->type==OB_ARMATURE && ob->pose) {
+			bPoseChannel *pchan;
+			for(pchan= ob->pose->chanbase.first; pchan; pchan= pchan->next) {
+				for (con = pchan->constraints.first; con; con=con->next) {
+					if (con->type==CONSTRAINT_TYPE_PYTHON) {
+						bPythonConstraint *data = con->data;
+						if (data->text==text) data->text = NULL;
+						update = 1;
+						
+					}
+				}
+			}
+		}
+		for (con = ob->constraints.first; con; con=con->next) {
+			if (con->type==CONSTRAINT_TYPE_PYTHON) {
+				bPythonConstraint *data = con->data;
+				if (data->text==text) data->text = NULL;
+				update = 1;
+			}
+		}
+		
+		if (update) {
+			DAG_object_flush_update(G.scene, ob, OB_RECALC_DATA);
+		}
+	}
+}
+
 /* This function is called to update PyConstraint data so that it is compatible with the script. 
  * Some of the allocating/freeing of memory for constraint targets occurs here, espcially
  * if the number of targets changes.

source/blender/python/api2_2x/Text.c

@@ -1,5 +1,5 @@
 /* 
- * $Id: Text.c 11123 2007-06-29 08:59:26Z campbellbarton $
+ * $Id$
  *
  * ***** BEGIN GPL/BL DUAL LICENSE BLOCK *****
  *
@@ -289,6 +289,7 @@ static PyObject *M_Text_unlink( PyObject * self, PyObject * args )
 					      "this text was already unlinked!" );
 
 	BPY_clear_bad_scriptlinks( text );
+	BPY_free_pyconstraint_links( text );
 	free_text_controllers( text );
 	unlink_text( text );
 

source/blender/python/api2_2x/bpy_data.c

@@ -621,7 +621,7 @@ PyObject *LibBlockSeq_unlink(BPy_LibBlockSeq *self, PyObject * value)
 			
 			if (!data)
 				return EXPP_ReturnPyObjError( PyExc_RuntimeError,
-						"This Group has been removed alredy" );
+						"This Group has been removed already" );
 			
 			/* Run the removal code */
 			free_group(data);
@@ -642,10 +642,11 @@ PyObject *LibBlockSeq_unlink(BPy_LibBlockSeq *self, PyObject * value)
 			
 			if (!data)
 				return EXPP_ReturnPyObjError( PyExc_RuntimeError,
-						"This Group has been removed alredy" );
+						"This Group has been removed already" );
 			
 			/* Run the removal code */
 			BPY_clear_bad_scriptlinks( data );
+			BPY_free_pyconstraint_links( data );
 			free_text_controllers( data );
 			unlink_text( data );
 			free_libblock( &G.main->text, data );