From f838597b5faec9994155edd191a8d16482cdee63 Mon Sep 17 00:00:00 2001
From: Rohan Bansal <rohan@digithinkit.com>
Date: Tue, 20 Nov 2018 13:12:13 +0530
Subject: [PATCH] fix(task): Fix error when trying to convert a task into a
 group even if no child tasks exist

---
 erpnext/projects/doctype/task/task.js | 10 +++++-----
 erpnext/projects/doctype/task/task.py | 15 ++++++++++-----
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/erpnext/projects/doctype/task/task.js b/erpnext/projects/doctype/task/task.js
index b8f324a85f..c1a9c448b4 100644
--- a/erpnext/projects/doctype/task/task.js
+++ b/erpnext/projects/doctype/task/task.js
@@ -80,15 +80,15 @@ frappe.ui.form.on("Task", {
 		}
 	},
 
-	is_group: function(frm) {
+	is_group: function (frm) {
 		frappe.call({
-			method:"erpnext.projects.doctype.task.task.check_if_child_exists",
+			method: "erpnext.projects.doctype.task.task.check_if_child_exists",
 			args: {
 				name: frm.doc.name
 			},
-			callback: function(r){
-				if(r.message){
-					frappe.msgprint(__('Cannot convert it to non-group. Child Tasks exist.'));
+			callback: function (r) {
+				if (r.message.length > 0) {
+					frappe.msgprint(__(`Cannot convert it to non-group. The following child Tasks exist: ${r.message.join(", ")}.`));
 					frm.reload_doc();
 				}
 			}
diff --git a/erpnext/projects/doctype/task/task.py b/erpnext/projects/doctype/task/task.py
index 3dc52d4ebe..649d73a63f 100755
--- a/erpnext/projects/doctype/task/task.py
+++ b/erpnext/projects/doctype/task/task.py
@@ -2,12 +2,15 @@
 # License: GNU General Public License v3. See license.txt
 
 from __future__ import unicode_literals
-import frappe, json
 
-from frappe.utils import getdate, date_diff, add_days, cstr
+import json
+
+import frappe
 from frappe import _, throw
+from frappe.utils import add_days, cstr, date_diff, get_link_to_form, getdate
 from frappe.utils.nestedset import NestedSet
 
+
 class CircularReferenceError(frappe.ValidationError): pass
 
 class Task(NestedSet):
@@ -157,8 +160,10 @@ class Task(NestedSet):
 
 @frappe.whitelist()
 def check_if_child_exists(name):
-	return frappe.db.sql("""select name from `tabTask`
-		where parent_task = %s""", name)
+	child_tasks = frappe.get_all("Task", filters={"parent_task": name})
+	child_tasks = [get_link_to_form("Task", task.name) for task in child_tasks]
+	return child_tasks
+
 
 def get_project(doctype, txt, searchfield, start, page_len, filters):
 	from erpnext.controllers.queries import get_match_cond
@@ -237,4 +242,4 @@ def add_multiple_tasks(data, parent):
 		new_task.insert()
 
 def on_doctype_update():
-	frappe.db.add_index("Task", ["lft", "rgt"])
\ No newline at end of file
+	frappe.db.add_index("Task", ["lft", "rgt"])