Wagtail创建页面遇Path已存在ValidationError问题求助

在Wagtail后台尝试在/en-us/events/下创建新页面时，触发错误：

django.core.exceptions.ValidationError: {'path': ['Page with this Path already exists.']}

通过Django Shell查询当前页面树：

from wagtail.models import Page
[(p.url, p.path) for p in Page.objects.all()]

返回结果：

[(None, '0001'),
 ('/en-us/', '00010001'),
 ('/en-us/events/', '000100010001'),
 ('/en-us/events/webinars/', '0001000100010001'),
 ('/en-us/events/webinars/some-webinar/', '00010001000100010001'),
 ('/en-us/events/newsletter/', '0001000100010002')]

调试发现新页面尝试使用的path为0001000100010002，但该path已被/en-us/events/newsletter/占用。执行python manage.py fixtree后，工具提示无问题：

Checking page tree for problems...
No problems found.

Checking collection tree for problems...
No problems found.

使用环境：Django 4.2.9、Wagtail 5.2.3（附带wagtail-localize 1.8、wagtailmenus 3.1.9、wagtail-metadata 4.0.2）

• 修复父页面的numchild字段
  Wagtail生成新页面path依赖父页面的numchild值，可能/en-us/events/的该字段未同步实际子页面数量。进入Django Shell执行：

  from wagtail.models import Page
  events_page = Page.objects.get(path='000100010001')
  actual_children = Page.objects.filter(path__startswith=events_page.path).exclude(path=events_page.path).count()
  print(f"当前numchild值: {events_page.numchild}, 实际子页面数: {actual_children}")
  if events_page.numchild != actual_children:
      events_page.numchild = actual_children
      events_page.save()
  

• 重置子页面的path序列
  若上述操作无效，可手动重新分配子页面的path编号（操作前务必备份数据库）：

  from wagtail.models import Page
  events_page = Page.objects.get(path='000100010001')
  children = Page.objects.filter(path__startswith=events_page.path).exclude(path=events_page.path).order_by('path')
  
  for index, child in enumerate(children, start=1):
      new_path = f"{events_page.path}{index:04d}"
      if child.path != new_path:
          child.path = new_path
          child.save()
          # 递归更新子页面的后代path
          descendants = Page.objects.filter(path__startswith=child.path).exclude(path=child.path)
          for desc in descendants:
              desc.path = new_path + desc.path[len(child.path):]
              desc.save()
  
  events_page.numchild = children.count()
  events_page.save()
  

• 检查wagtail-localize的本地化页面冲突
  由于使用了wagtail-localize，可能存在未同步的本地化页面导致path重复。执行以下查询检查：

  from wagtail_localize.models import Translation
  events_page = Page.objects.get(path='000100010001')
  translations = Translation.objects.filter(source_page=events_page)
  print([(t.target_page.url, t.target_page.path) for t in translations])
  

  若发现重复path，手动删除或修复冲突的本地化页面。

• 清理缓存并重启服务
  执行完上述操作后，清理缓存并重启服务：

  python manage.py clearcache
  

内容的提问来源于stack exchange，提问作者Martí Bosch