fix: 明确提示超大 PNG 像素限制

app/pages/admin/media.vue

@@ -90,7 +90,7 @@ const formatBytes = (bytes: number) => bytes < 1024 * 1024 ? `${Math.ceil(bytes
       <div v-if="loading" class="admin-loading">正在加载素材…</div>
       <div v-else class="media-admin-body">
         <section v-if="view === 'active'" class="media-upload-panel editor-panel">
-          <div><PhUploadSimple :size="30" /><strong>上传新图片</strong><small>支持 JPG、PNG、WebP；最大 8MB、4000 万像素</small></div>
+          <div><PhUploadSimple :size="30" /><strong>上传新图片</strong><small>支持 JPG、PNG、WebP；最大 8MB、4000 万像素。Logo 建议使用透明 PNG，宽度 600–1600px</small></div>
           <div class="media-upload-meta"><input v-model="uploadMeta.altText" placeholder="ALT 描述（建议填写）"><input v-model="uploadMeta.source" placeholder="素材来源"><input v-model="uploadMeta.copyright" placeholder="版权/授权说明"><select v-model="uploadMeta.authorizationStatus"><option value="pending">待核验</option><option value="authorized">已授权</option><option value="restricted">限制使用</option></select></div>
           <label class="media-upload-button"><input type="file" accept="image/jpeg,image/png,image/webp" :disabled="busy" @change="upload">{{ busy ? '处理中…' : '选择并上传图片' }}</label>
         </section>

server/api/admin/media.post.ts

@@ -3,6 +3,7 @@ import { mkdir, rm, writeFile } from 'node:fs/promises'
 import { extname } from 'node:path'
 import sharp from 'sharp'
 import { z } from 'zod'
+import { MAX_IMAGE_BYTES, MAX_IMAGE_HEIGHT, MAX_IMAGE_PIXELS, MAX_IMAGE_WIDTH, isSharpPixelLimitError } from '../../utils/image-validation'
 import { mediaUrl, safeUploadPath, serializeMedia, type MediaAssetRow } from '../../utils/media'
 import { useDatabase } from '../../utils/db'
 
@@ -30,7 +31,7 @@ export default defineEventHandler(async (event) => {
   const parts = await readMultipartFormData(event)
   const file = parts?.find(part => part.name === 'file' && part.filename)
   if (!file?.data?.length) throw createError({ statusCode: 400, statusMessage: '请选择图片文件' })
-  if (file.data.length > 8 * 1024 * 1024) throw createError({ statusCode: 413, statusMessage: '单张图片不能超过 8MB' })
+  if (file.data.length > MAX_IMAGE_BYTES) throw createError({ statusCode: 413, statusMessage: '单张图片不能超过 8MB' })
 
   const detectedType = detectImageType(file.data)
   if (!detectedType || !(detectedType in allowedTypes)) throw createError({ statusCode: 415, statusMessage: '仅支持 JPG、PNG、WebP 图片' })
@@ -39,11 +40,16 @@ export default defineEventHandler(async (event) => {
   if (!typeConfig.inputExtensions.includes(inputExtension as never)) throw createError({ statusCode: 415, statusMessage: '文件扩展名与实际图片类型不一致' })
 
   let imageMetadata
-  try { imageMetadata = await sharp(file.data, { limitInputPixels: 40_000_000 }).metadata() }
+  try { imageMetadata = await sharp(file.data, { limitInputPixels: MAX_IMAGE_PIXELS }).metadata() }
-  catch { throw createError({ statusCode: 415, statusMessage: '图片内容损坏或无法解析' }) }
+  catch (error) {
+    if (isSharpPixelLimitError(error)) {
+      throw createError({ statusCode: 413, statusMessage: '图片像素过大，请压缩至 10000×10000 且不超过 4000 万像素后上传' })
+    }
+    throw createError({ statusCode: 415, statusMessage: '图片内容损坏或无法解析' })
+  }
   const width = imageMetadata.width || 0
   const height = imageMetadata.height || 0
-  if (!width || !height || width > 10_000 || height > 10_000 || width * height > 40_000_000) {
+  if (!width || !height || width > MAX_IMAGE_WIDTH || height > MAX_IMAGE_HEIGHT || width * height > MAX_IMAGE_PIXELS) {
     throw createError({ statusCode: 413, statusMessage: '图片尺寸不能超过 10000×10000 或 4000 万像素' })
   }
 

server/utils/image-validation.ts

@@ -0,0 +1,8 @@
+export const MAX_IMAGE_BYTES = 8 * 1024 * 1024
+export const MAX_IMAGE_WIDTH = 10_000
+export const MAX_IMAGE_HEIGHT = 10_000
+export const MAX_IMAGE_PIXELS = 40_000_000
+
+export function isSharpPixelLimitError(error: unknown) {
+  return error instanceof Error && /exceeds pixel limit/i.test(error.message)
+}

tests/image-validation.test.ts

@@ -0,0 +1,13 @@
+import { describe, expect, it } from 'vitest'
+import { MAX_IMAGE_PIXELS, isSharpPixelLimitError } from '../server/utils/image-validation'
+
+describe('图片上传校验', () => {
+  it('识别 Sharp 像素上限错误', () => {
+    expect(isSharpPixelLimitError(new Error('Input image exceeds pixel limit'))).toBe(true)
+  })
+
+  it('不把普通解析错误误判为像素过大', () => {
+    expect(isSharpPixelLimitError(new Error('Input buffer contains unsupported image format'))).toBe(false)
+    expect(MAX_IMAGE_PIXELS).toBe(40_000_000)
+  })
+})