From fa4e9540fed7460abd4b07f430e3045a8ad28f6a Mon Sep 17 00:00:00 2001
From: Anand Doshi <anand@erpnext.com>
Date: Fri, 7 Feb 2014 14:50:44 +0530
Subject: [PATCH] BugFix: Nested Set Model - on_trash and before_rename

Also, minor fix in bean
---
 webnotes/model/bean.py      |  2 +-
 webnotes/utils/nestedset.py | 16 ++++++++++++++--
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/webnotes/model/bean.py b/webnotes/model/bean.py
index 9798984ec3..431e5ad8a5 100644
--- a/webnotes/model/bean.py
+++ b/webnotes/model/bean.py
@@ -232,7 +232,7 @@ class Bean:
 			add_to_response(webnotes.local.response, 
 				webnotes.call(getattr(self.controller, method), *args, **kwargs))
 
-		args = [self, method] + args
+		args = [self, method] + list(args)
 		for handler in webnotes.get_hooks("bean_event:" + self.doc.doctype + ":" + method) \
 			+ webnotes.get_hooks("bean_event:*:" + method):
 			add_to_response(webnotes.local.response, webnotes.call(webnotes.get_attr(handler), *args, **kwargs))
diff --git a/webnotes/utils/nestedset.py b/webnotes/utils/nestedset.py
index ab654ba97f..fa55611732 100644
--- a/webnotes/utils/nestedset.py
+++ b/webnotes/utils/nestedset.py
@@ -17,6 +17,8 @@ from webnotes import msgprint, _
 
 class NestedSetRecursionError(webnotes.ValidationError): pass
 class NestedSetMultipleRootsError(webnotes.ValidationError): pass
+class NestedSetChildExistsError(webnotes.ValidationError): pass
+class NestedSetInvalidMergeError(webnotes.ValidationError): pass
 
 # called in the on_update method
 def update_nsm(doc_obj):
@@ -188,19 +190,29 @@ class DocTypeNestedSet(object):
 	def on_trash(self):
 		if not self.nsm_parent_field:
 			self.nsm_parent_field = webnotes.scrub(self.doc.doctype) + "_parent"
+		
 		parent = self.doc.fields[self.nsm_parent_field]
 		if not parent:
 			msgprint(_("Root ") + self.doc.doctype + _(" cannot be deleted."), raise_exception=1)
+		
+		# cannot delete non-empty group
+		has_children = webnotes.conn.sql("""select count(name) from `tab{doctype}`
+			where `{nsm_parent_field}`=%s""".format(doctype=self.doc.doctype, nsm_parent_field=self.nsm_parent_field),
+			(self.doc.name,))[0][0]
+		if has_children:
+			webnotes.throw("{cannot_delete}. {children_exist}: {name}.".format(
+				children_exist=_("Children exist for"), name=self.doc.name,
+				cannot_delete=_("Cannot delete")), NestedSetChildExistsError)
 
 		self.doc.fields[self.nsm_parent_field] = ""
 		update_nsm(self)
 		
-	def before_rename(self, newdn, olddn, merge=False, group_fname="is_group"):
+	def before_rename(self, olddn, newdn, merge=False, group_fname="is_group"):
 		if merge:
 			is_group = webnotes.conn.get_value(self.doc.doctype, newdn, group_fname)
 			if self.doc.fields[group_fname] != is_group:
 				webnotes.throw(_("""Merging is only possible between Group-to-Group or 
-					Ledger-to-Ledger"""))
+					Ledger-to-Ledger"""), NestedSetInvalidMergeError)
 					
 	def after_rename(self, olddn, newdn, merge=False):
 		if merge: