From d863e753d7267768356ad69491c5af5ec0b87f43 Mon Sep 17 00:00:00 2001
From: MeiMei <30769358+mei23@users.noreply.github.com>
Date: Tue, 1 Oct 2019 01:46:31 +0900
Subject: [PATCH] Apply DB limit to the maximum note text length (#5465)

---
 src/misc/hard-limits.ts                       | 8 ++++++++
 src/server/api/endpoints/admin/update-meta.ts | 3 ++-
 src/server/api/endpoints/meta.ts              | 3 ++-
 src/server/api/endpoints/notes/create.ts      | 5 ++++-
 4 files changed, 16 insertions(+), 3 deletions(-)
 create mode 100644 src/misc/hard-limits.ts

diff --git a/src/misc/hard-limits.ts b/src/misc/hard-limits.ts
new file mode 100644
index 000000000..2a61cb321
--- /dev/null
+++ b/src/misc/hard-limits.ts
@@ -0,0 +1,8 @@
+
+// If you change DB_* values, you must also change the DB schema.
+
+/**
+ * Maximum note text length that can be stored in DB.
+ * Surrogate pairs count as one
+ */
+export const DB_MAX_NOTE_TEXT_LENGTH = 8192;
diff --git a/src/server/api/endpoints/admin/update-meta.ts b/src/server/api/endpoints/admin/update-meta.ts
index 1d6973e7a..05a1e25c0 100644
--- a/src/server/api/endpoints/admin/update-meta.ts
+++ b/src/server/api/endpoints/admin/update-meta.ts
@@ -3,6 +3,7 @@ import define from '../../define';
 import { getConnection } from 'typeorm';
 import { Meta } from '../../../../models/entities/meta';
 import { insertModerationLog } from '../../../../services/insert-moderation-log';
+import { DB_MAX_NOTE_TEXT_LENGTH } from '../../../../misc/hard-limits';
 
 export const meta = {
 	desc: {
@@ -121,7 +122,7 @@ export const meta = {
 		},
 
 		maxNoteTextLength: {
-			validator: $.optional.num.min(0),
+			validator: $.optional.num.min(0).max(DB_MAX_NOTE_TEXT_LENGTH),
 			desc: {
 				'ja-JP': '投稿の最大文字数'
 			}
diff --git a/src/server/api/endpoints/meta.ts b/src/server/api/endpoints/meta.ts
index c07a1c07b..0b56a9d4e 100644
--- a/src/server/api/endpoints/meta.ts
+++ b/src/server/api/endpoints/meta.ts
@@ -7,6 +7,7 @@ import * as pkg from '../../../../package.json';
 import { Emojis } from '../../../models';
 import { getConnection } from 'typeorm';
 import redis from '../../../db/redis';
+import { DB_MAX_NOTE_TEXT_LENGTH } from '../../../misc/hard-limits';
 
 export const meta = {
 	stability: 'stable',
@@ -138,7 +139,7 @@ export default define(meta, async (ps, me) => {
 		bannerUrl: instance.bannerUrl,
 		errorImageUrl: instance.errorImageUrl,
 		iconUrl: instance.iconUrl,
-		maxNoteTextLength: instance.maxNoteTextLength,
+		maxNoteTextLength: Math.min(instance.maxNoteTextLength, DB_MAX_NOTE_TEXT_LENGTH),
 		emojis: emojis.map(e => ({
 			id: e.id,
 			aliases: e.aliases,
diff --git a/src/server/api/endpoints/notes/create.ts b/src/server/api/endpoints/notes/create.ts
index 1650de907..6e392c03f 100644
--- a/src/server/api/endpoints/notes/create.ts
+++ b/src/server/api/endpoints/notes/create.ts
@@ -10,6 +10,7 @@ import { User } from '../../../../models/entities/user';
 import { Users, DriveFiles, Notes } from '../../../../models';
 import { DriveFile } from '../../../../models/entities/drive-file';
 import { Note } from '../../../../models/entities/note';
+import { DB_MAX_NOTE_TEXT_LENGTH } from '../../../../misc/hard-limits';
 
 let maxNoteTextLength = 1000;
 
@@ -55,7 +56,9 @@ export const meta = {
 
 		text: {
 			validator: $.optional.nullable.str.pipe(text =>
-				length(text.trim()) <= maxNoteTextLength && text.trim() != ''
+				text.trim() != ''
+					&& length(text.trim()) <= maxNoteTextLength
+					&& Array.from(text.trim()).length <= DB_MAX_NOTE_TEXT_LENGTH	// DB limit
 			),
 			default: null as any,
 			desc: {