perf: reuse _doc_before_save in doc.get_latest (backport #19326) (#…

…19345)

* perf: reuse `_doc_before_save` in `doc.get_latest`

(cherry picked from commit c453ad2)

# Conflicts:
#	frappe/model/base_document.py

* test: improve doctype and field naming

(cherry picked from commit 9ad9c39)

# Conflicts:
#	frappe/tests/test_linked_with.py

* chore: resolve conflicts

* fix: add validation for reserved keywords when saving DocType (backport)

Co-authored-by: Sagar Vora <sagar@resilient.tech>

frappe/core/doctype/doctype/doctype.py

@@ -931,12 +931,13 @@ def check_illegal_characters(fieldname):
 		validate_column_name(fieldname)
 
 	def check_invalid_fieldnames(docname, fieldname):
-		invalid_fields = ("doctype",)
-		if fieldname in invalid_fields:
+		if fieldname in Document._reserved_keywords:
 			frappe.throw(
-				_("{0}: Fieldname cannot be one of {1}").format(
-					docname, ", ".join([frappe.bold(d) for d in invalid_fields])
-				)
+				_("{0}: fieldname cannot be set to reserved keyword {1}").format(
+					frappe.bold(docname),
+					frappe.bold(fieldname),
+				),
+				title=_("Invalid Fieldname"),
 			)
 
 	def check_unique_fieldname(docname, fieldname):

frappe/model/base_document.py

@@ -85,7 +85,18 @@ def _get_controller():
 
 
 class BaseDocument(object):
-	ignore_in_setter = ("doctype", "_meta", "meta", "_table_fields", "_valid_columns")
+	_reserved_keywords = {
+		"doctype",
+		"meta",
+		"_meta",
+		"flags",
+		"parent_doc",
+		"_table_fields",
+		"_valid_columns",
+		"_doc_before_save",
+		"_reserved_keywords",
+		"dont_update_if_missing",
+	}
 
 	def __init__(self, d):
 		if d.get("doctype"):
@@ -170,7 +181,7 @@ def getone(self, key, filters=None):
 		return self.get(key, filters=filters, limit=1)[0]
 
 	def set(self, key, value, as_value=False):
-		if key in self.ignore_in_setter:
+		if key in self._reserved_keywords:
 			return
 
 		if isinstance(value, list) and not as_value:

frappe/model/document.py

@@ -191,9 +191,10 @@ def load_from_db(self):
 			self.__setup__()
 
 	def get_latest(self):
-		if not getattr(self, "latest", None):
-			self.latest = frappe.get_doc(self.doctype, self.name)
-		return self.latest
+		if not hasattr(self, "_doc_before_save"):
+			self.load_doc_before_save()
+
+		return self._doc_before_save
 
 	def check_permission(self, permtype="read", permlevel=None):
 		"""Raise `frappe.PermissionError` if not permitted"""