diff --git a/frappe/model/base_document.py b/frappe/model/base_document.py
index 41714d4d49..667fe88df6 100644
--- a/frappe/model/base_document.py
+++ b/frappe/model/base_document.py
@@ -267,6 +267,7 @@ class BaseDocument(object):
 
 			docname = self.get(df.fieldname)
 			if docname:
+				# MySQL is case insensitive. Preserve case of the original docname in the Link Field.
 				value = frappe.db.get_value(doctype, docname)
 				setattr(self, df.fieldname, value)
 			if docname and not value:
diff --git a/frappe/model/document.py b/frappe/model/document.py
index 30d019ad3b..66e1bd1bf0 100644
--- a/frappe/model/document.py
+++ b/frappe/model/document.py
@@ -371,8 +371,11 @@ class Document(BaseDocument):
 		"""run standard triggers, plus those in frappe"""
 		if hasattr(self, method):
 			fn = lambda self, *args, **kwargs: getattr(self, method)(*args, **kwargs)
-			fn.__name__ = method.encode("utf-8")
-			return Document.hook(fn)(self, *args, **kwargs)
+		else:
+			fn = lambda self, *args, **kwargs: None
+
+		fn.__name__ = method.encode("utf-8")
+		return Document.hook(fn)(self, *args, **kwargs)
 
 	def submit(self):
 		self.docstatus = 1