Index: source/blender/editors/mesh/editmesh_select.c
===================================================================
--- source/blender/editors/mesh/editmesh_select.c	(Revision 60953)
+++ source/blender/editors/mesh/editmesh_select.c	(Arbeitskopie)
@@ -74,6 +74,9 @@
 /* use bmesh operator flags for a few operators */
 #define BMO_ELE_TAG 1
 
+
+int edbm_select_linked_exec(bContext *C, wmOperator *op);
+
 /* ****************************** MIRROR **************** */
 
 void EDBM_select_mirrored(BMEditMesh *em, bool extend,
@@ -847,6 +850,8 @@
 	PropertyRNA *prop = RNA_struct_find_property(op->ptr, "threshold");
 
 	const int type = RNA_enum_get(op->ptr, "type");
+	const bool linked = RNA_boolean_get(op->ptr, "linked");
+	int ret;
 
 	if (!RNA_property_is_set(op->ptr, prop)) {
 		RNA_property_float_set(op->ptr, prop, ts->select_thresh);
@@ -855,9 +860,17 @@
 		ts->select_thresh = RNA_property_float_get(op->ptr, prop);
 	}
 
-	if      (type < 100) return similar_vert_select_exec(C, op);
-	else if (type < 200) return similar_edge_select_exec(C, op);
-	else                 return similar_face_select_exec(C, op);
+	if      (type < 100) ret = similar_vert_select_exec(C, op);
+	else if (type < 200) ret = similar_edge_select_exec(C, op);
+	else                 ret = similar_face_select_exec(C, op);
+	
+	if (linked)
+	{
+		/* extend selection to islands */
+		ret = edbm_select_linked_exec(C, op);
+	}
+	
+	return ret;
 }
 
 static EnumPropertyItem *select_similar_type_itemf(bContext *C, PointerRNA *UNUSED(ptr), PropertyRNA *UNUSED(prop),
@@ -929,6 +942,9 @@
 	RNA_def_enum(ot->srna, "compare", prop_similar_compare_types, SIM_CMP_EQ, "Compare", "");
 
 	RNA_def_float(ot->srna, "threshold", 0.0, 0.0, 1.0, "Threshold", "", 0.0, 1.0);
+	
+	RNA_def_boolean(ot->srna, "linked", false, "Linked", "Select all geometry linked to initial selection");
+	RNA_def_boolean(ot->srna, "limit", false, "Limit Linked by Seams", "");
 }
 
 
@@ -1850,7 +1866,7 @@
 	}
 }
 
-static int edbm_select_linked_exec(bContext *C, wmOperator *op)
+int edbm_select_linked_exec(bContext *C, wmOperator *op)
 {
 	Object *obedit = CTX_data_edit_object(C);
 	BMEditMesh *em = BKE_editmesh_from_object(obedit);