fix: order and bound the revisions query in WikiPage.get_context

wiki/wiki/doctype/wiki_page/test_wiki_page.py

@@ -69,6 +69,74 @@ def test_wiki_page_lifecycle(self):
 			2,
 		)
 
+	def test_get_context_orders_revisions_by_creation_not_modified(self):
+		"""`current_revision` is the newest revision, `previous_revision` the next.
+
+		Frappe supplies a default `ORDER BY` from the doctype's `sort_field`,
+		which for Wiki Page Revision is `modified DESC`. That is not the same
+		thing as newest-first: touching an old revision's row moves it to the
+		front and it is then presented as the current one. This gives `modified`
+		the opposite order to `creation` so the two orderings disagree, and
+		asserts the chronological answer.
+		"""
+		space = frappe.new_doc("Wiki Space")
+		space.route = "wiki-revision-order-space"
+		space.append("wiki_sidebars", {"parent_label": "Group", "wiki_page": self.wiki_page.name})
+		space.insert()
+		self.addCleanup(lambda: frappe.delete_doc("Wiki Space", space.name, force=True))
+
+		# `after_insert` already made one revision; add two more, oldest first.
+		ordered = frappe.db.get_all(
+			"Wiki Page Revision", filters={"wiki_page": self.wiki_page.name}, pluck="name"
+		)
+		for content in ("second", "third"):
+			revision = frappe.new_doc("Wiki Page Revision")
+			revision.append("wiki_pages", {"wiki_page": self.wiki_page.name})
+			revision.content = content
+			revision.message = content
+			revision.insert()
+			ordered.append(revision.name)
+
+		self.assertEqual(len(ordered), 3)
+		oldest, middle, newest = ordered
+
+		# `creation` ascends with insertion; `modified` runs the other way, so
+		# the default `modified DESC` ordering puts the *oldest* revision first.
+		for name, created, modified in (
+			(oldest, "2024-01-01 10:00:00", "2024-06-03 10:00:00"),
+			(middle, "2024-01-02 10:00:00", "2024-06-02 10:00:00"),
+			(newest, "2024-01-03 10:00:00", "2024-06-01 10:00:00"),
+		):
+			frappe.db.set_value(
+				"Wiki Page Revision", name, {"creation": created, "modified": modified},
+				update_modified=False,
+			)
+
+		context = frappe._dict()
+		frappe.get_doc("Wiki Page", self.wiki_page.name).get_context(context)
+
+		self.assertEqual(context.current_revision.name, newest)
+		self.assertEqual(context.previous_revision.name, middle)
+		self.assertNotIn(oldest, [context.current_revision.name, context.previous_revision.name])
+
+	def test_get_context_handles_a_page_with_one_revision(self):
+		"""A single revision still yields the placeholder for the previous one."""
+		space = frappe.new_doc("Wiki Space")
+		space.route = "wiki-single-revision-space"
+		space.append("wiki_sidebars", {"parent_label": "Group", "wiki_page": self.wiki_page.name})
+		space.insert()
+		self.addCleanup(lambda: frappe.delete_doc("Wiki Space", space.name, force=True))
+
+		self.assertEqual(
+			len(frappe.db.get_all("Wiki Page Revision", filters={"wiki_page": self.wiki_page.name})), 1
+		)
+
+		context = frappe._dict()
+		frappe.get_doc("Wiki Page", self.wiki_page.name).get_context(context)
+
+		self.assertEqual(context.previous_revision["name"], "")
+		self.assertEqual(context.previous_revision["content"], "<h3>No Revisions</h3>")
+
 	def test_wiki_page_deletion(self):
 		delete_wiki_page(f"{self.wiki_page.route}")
 		self.assertEqual(frappe.db.exists("Wiki Page", self.wiki_page.name), None)

wiki/wiki/doctype/wiki_page/wiki_page.py

@@ -301,6 +301,8 @@ def get_context(self, context):
 			"Wiki Page Revision",
 			filters=[["wiki_page", "=", self.name]],
 			fields=["content", "creation", "owner", "name", "raised_by", "raised_by_username"],
+			order_by="creation desc",
+			limit_page_length=2,
 		)
 		context.current_revision = revisions[0]
 		if len(revisions) > 1: