#428

backend/app/controllers/tag_versions_controller.rb

@@ -35,8 +35,18 @@ class TagVersionsController < ApplicationController
   private
 
   def serialise_versions rows, language_code
+    rows = rows.to_a
     user_ids = rows.map(&:created_by_user_id).compact.uniq
     users_by_id = User.where(id: user_ids).pluck(:id, :name).to_h
+    parent_ids = rows.flat_map do |row|
+      split_parent_tag_ids(row.parent_tag_ids) +
+          split_parent_tag_ids(row.attributes['prev_parent_tag_ids'])
+    end.uniq
+    parents_by_id = Tag.includes(
+        :tag_names, :materials, :deerjikists, :tag_descriptions,
+        parents: [:tag_names, :materials, :deerjikists, :tag_descriptions])
+        .where(id: parent_ids).index_by(&:id)
+    parent_json = parents_by_id.transform_values { TagRepr.base(_1, language_code:) }
 
     rows.map do |row|
       current_names = names_for_locale(row.names, language_code)
@@ -47,18 +57,10 @@ class TagVersionsController < ApplicationController
       cur_parent_tag_ids = split_parent_tag_ids(row.parent_tag_ids)
       prev_parent_tag_ids = split_parent_tag_ids(row.attributes['prev_parent_tag_ids'])
 
-      all_parent_tag_ids = (cur_parent_tag_ids | prev_parent_tag_ids)
-
-      tags_by_id =
-          Tag
-          .includes(:tag_names, :materials, :tag_descriptions, parents: :tag_descriptions)
-          .where(id: all_parent_tag_ids)
-          .index_by(&:id)
-
       parent_tags =
           build_version_values(cur_parent_tag_ids, prev_parent_tag_ids, key: :tag_id)
           .map do |h|
-            { tag: TagRepr.base(tags_by_id[h[:tag_id]], language_code:),
+            { tag: parent_json.fetch(h[:tag_id]),
               type: h[:type] }
           end
 
@@ -66,6 +68,7 @@ class TagVersionsController < ApplicationController
         version_no: row.version_no,
         event_type: row.event_type,
         names: row.names,
+        name_changes: name_changes(row.names, row.attributes['prev_names']),
         name: { current: current_names['name'], prev: previous_names['name'] },
         category: { current: row.category, prev: row.attributes['prev_category'] },
         deprecated_at: { current: row.deprecated_at&.iso8601,
@@ -97,11 +100,44 @@ class TagVersionsController < ApplicationController
   def split_values(values) = values.to_s.split(/\s+/).reject(&:blank?)
 
   def names_for_locale names, language_code
+    values = snapshot_names(names)[language_code]
+    values.is_a?(Hash) ? values : {}
+  end
+
+  def snapshot_names names
     values = names.is_a?(String) ? JSON.parse(names) : names
-    values&.fetch(language_code, {}) || {}
+    values.is_a?(Hash) ? values : {}
   rescue JSON::ParserError
     {}
   end
 
+  def name_changes current_names, previous_names
+    current = snapshot_names(current_names)
+    previous = snapshot_names(previous_names)
+    (current.keys | previous.keys).sort.filter_map do |language|
+      current_name = language_snapshot(current[language])
+      previous_name = language_snapshot(previous[language])
+      next if current_name == previous_name
+
+      { language_code: language, current: current_name, prev: previous_name }
+    end
+  end
+
+  def language_snapshot entry
+    return nil unless entry.is_a?(Hash)
+
+    aliases = Array(entry['aliases']).filter_map do |value|
+      value = { 'name' => value } if value.is_a?(String)
+      next unless value.is_a?(Hash) && value['name'].is_a?(String)
+
+      { name: value['name'], script_code: value['script_code'] }
+    end
+    aliases = aliases.uniq.sort_by { [_1[:name], _1[:script_code].to_s] }
+    { name: entry['name'],
+      script_code: entry['script_code'],
+      auto_generated: entry['auto_generated'],
+      aliases: }
+  end
+
   def split_parent_tag_ids(values) = split_values(values).map(&:to_i)
 end

backend/app/controllers/wiki_pages_controller.rb

@@ -37,27 +37,18 @@ class WikiPagesController < ApplicationController
   def autolink_candidates
     locale = resolve_locale!
     language = params.fetch(:language, locale.language_code)
+    language = 'ja' if language == 'und'
     return head :not_found unless language.is_a?(String)
-    target_locale =
-        if language == 'und'
-          locale
-        else
-          Locale.where(language_code: language, deprecated_at: nil,
-                       code: Locale.codes.values).order(:code).first
-        end
-    return head :not_found unless target_locale
+    return head :not_found unless Language.exists?(code: language)
 
-    candidates = []
-    unless language == 'und'
-      names = TagDescription.joins(tag: :tag_names)
-          .where(language_code: language, tag_names: { language_code: language })
-          .pluck('tag_descriptions.tag_id', 'tag_descriptions.id', 'tag_names.name')
-      candidates = names.map do |tag_id, description_id, name|
-        WikiPageRepr.autolink_tag(target_locale, tag_id:, description_id:, name:)
-      end
+    names = TagDescription.joins(tag: :tag_names)
+        .where(language_code: locale.language_code, tag_names: { language_code: language })
+        .pluck('tag_descriptions.tag_id', 'tag_descriptions.id', 'tag_names.name')
+    candidates = names.map do |tag_id, description_id, name|
+      WikiPageRepr.autolink_tag(locale, tag_id:, description_id:, name:, language:)
     end
     candidates.concat(TagGroup.order(:id).pluck(:id, :name).map do |id, name|
-      WikiPageRepr.autolink_group(target_locale, id:, name:, language:)
+      WikiPageRepr.autolink_group(locale, id:, name:, language:)
     end)
     render json: candidates
   end

backend/app/models/locale.rb

@@ -1,8 +1,7 @@
 class Locale < ApplicationRecord
   attr_accessor :certified_tag_names_path
 
-  before_save :lock_tag_creation!, if: :will_generate_tag_names?
-  after_save :generate_tag_names!, if: :needs_tag_names?
+  around_save :save_with_tag_names!, if: :will_generate_tag_names?
 
   belongs_to :language, foreign_key: :language_code, primary_key: :code
   belongs_to :script, foreign_key: :script_code, primary_key: :code
@@ -17,11 +16,17 @@ class Locale < ApplicationRecord
     deprecated_at.nil? && (will_save_change_to_code? || will_save_change_to_deprecated_at?)
   end
 
-  def lock_tag_creation! = SharedResourceIdAllocator.lock_space!(Tag, 'tags')
+  def save_with_tag_names!
+    completed = self.class.transaction(requires_new: true) do
+      SharedResourceIdAllocator.lock_space!(Tag, 'tags')
+      saved = yield
+      raise ActiveRecord::RecordNotSaved, 'Locale save was halted' unless saved
 
-  def needs_tag_names?
-    deprecated_at.nil? && (saved_change_to_code? || saved_change_to_deprecated_at?)
+      TagNameCompletion.for_locale!(self)
+      true
+    end
+    unless completed
+      raise ActiveRecord::RecordNotSaved, 'Locale tag completion was rolled back'
+    end
   end
-
-  def generate_tag_names! = TagNameCompletion.for_locale!(self)
 end

backend/app/models/tag.rb

@@ -111,6 +111,11 @@ class Tag < ApplicationRecord
   def has_deerjikists = deerjikists.loaded? ? deerjikists.any? : deerjikists.exists?
 
   def snapshot_aliases language_code
+    if tag_names.loaded?
+      return tag_names.select { _1.language_code == language_code && !_1.primary? }
+          .sort_by(&:name).map(&:name)
+    end
+
     tag_names.where(language_code:, primary_flg: false).order(:name).pluck(:name)
   end
 

backend/app/representations/wiki_page_repr.rb

@@ -27,13 +27,13 @@ module WikiPageRepr
     TagGroupRepr.tag_group(tag_group).merge('resource_type' => 'tag_group')
   end
 
-  def autolink_tag locale, tag_id:, description_id:, name:
+  def autolink_tag locale, tag_id:, description_id:, name:, language:
     { resource_type: 'tag_description',
       resource_id: description_id,
       tag_id:,
       tag_description_id: description_id,
       name:,
-      language_code: locale.language_code,
+      language_code: language,
       locale_code: locale.code_before_type_cast }
   end
 

backend/app/services/shared_resource_id_allocator.rb

@@ -13,7 +13,19 @@ class SharedResourceIdAllocator
           ['tag_description_versions', 'tag_id']],
       'wiki' => [['tag_group_versions', 'tag_group_id']] }.freeze
   LOCK_TIMEOUT = 10
-  TRANSACTION_LOCKS = ObjectSpace::WeakMap.new
+  CONNECTION_LOCKS = ObjectSpace::WeakMap.new
+
+  class LockCleanup
+    def initialize &finish
+      @finish = finish
+    end
+
+    def trigger_transactional_callbacks? = false
+    def before_committed! = nil
+    def committed!(**) = @finish.call(self)
+    def rolledback!(**) = @finish.call(self)
+  end
+  private_constant :LockCleanup
 
   def self.assign! record
     space, tables = SPACES.find { |_name, names| names.include?(record.class.table_name) }
@@ -42,14 +54,14 @@ class SharedResourceIdAllocator
     raise ArgumentError, 'Unknown shared ID resource' unless SPACES.key?(space)
 
     connection = record_class.connection
-    transaction = record_class.current_transaction
+    transaction = connection.current_transaction
     unless transaction.open?
       raise ActiveRecord::ActiveRecordError, 'Shared ID requires a transaction'
     end
 
     database = connection.pool.db_config.database
     name = "btrc:ids:#{ Digest::SHA256.hexdigest(database)[0, 16] }:#{ space }"
-    held_locks = TRANSACTION_LOCKS[transaction] ||= {}
+    held_locks = CONNECTION_LOCKS[connection] ||= {}
     return if held_locks.key?(name)
 
     quoted_name = connection.quote(name)
@@ -61,20 +73,41 @@ class SharedResourceIdAllocator
     end
     held_locks[name] = true
 
-    release = lambda do
-      held_locks.delete(name)
+    finish = lambda do |cleanup|
+      next unless held_locks.key?(name)
+
+      # Savepoint callbacks may run before the outer transaction ends.
+      # Keep one session lock and transfer its cleanup to the remaining parent.
+      parent = connection.current_transaction
+      if parent.open?
+        connection.add_transaction_record(cleanup)
+        next
+      end
       result = record_class.uncached do
         connection.select_value("SELECT RELEASE_LOCK(#{ quoted_name })")
       end
       unless result.to_i == 1
         raise ActiveRecord::ActiveRecordError, "Shared ID lock release failed: #{ space }"
       end
+      held_locks.delete(name)
+    rescue StandardError
+      # Never return a session with an untracked advisory lock to the pool.
+      begin
+        connection.disconnect!
+      ensure
+        held_locks.clear
+      end
+      raise
     end
     begin
-      transaction.after_commit(&release)
-      transaction.after_rollback(&release)
+      # Rails finalises remaining records in ensure if another callback raises.
+      connection.add_transaction_record(LockCleanup.new(&finish))
     rescue StandardError
-      release.call
+      begin
+        connection.disconnect!
+      ensure
+        held_locks.clear
+      end
       raise
     end
   end

frontend/src/components/PostFormTagsArea.tsx

@@ -1,6 +1,6 @@
 // TODO: TagSearch と共通化する．
 
-import { useRef, useState } from 'react'
+import { useEffect, useRef, useState } from 'react'
 
 import { useLocale } from '@/lib/useLocale'
 import { useUITranslation } from '@/lib/useUITranslation'
@@ -46,11 +46,19 @@ const PostFormTagsArea: FC<Props> = ({ tags, setTags, errors, ...rest }) => {
 
   const [bounds, setBounds] = useState<{ start: number; end: number }> ({ start: 0, end: 0 })
   const [focused, setFocused] = useState (false)
-  const [suggestions, setSuggestions] = useState<Tag[]> ([])
+  const [request, setRequest] = useState ({ query: '' })
+  const [result, setResult] = useState<{
+      locale: string
+      request: { query: string }
+      tags: Tag[] }> ({ locale, request, tags: [] })
+  const currentToken = getTokenAt (tags, Math.min (bounds.start, tags.length)).token
+  const suggestions = (result.locale === locale && result.request === request
+      && request.query === currentToken) ? result.tags : []
   const [suggestionsVsbl, setSuggestionsVsbl] = useState (false)
 
   const handleTagSelect = (tag: Tag) => {
     setSuggestionsVsbl (false)
+    setRequest ({ query: '' })
     const textarea = ref.current!
     const newValue = replaceToken (tags, bounds.start, bounds.end, tag.name + ' ')
     setTags (newValue)
@@ -62,8 +70,10 @@ const PostFormTagsArea: FC<Props> = ({ tags, setTags, errors, ...rest }) => {
     })
   }
 
-  const recompute = async (pos: number, v: string = tags) => {
+  const recompute = (pos: number, v: string = tags) => {
     const { start, end, token } = getTokenAt (v, pos)
+    setRequest ({ query: token })
+    setSuggestionsVsbl (token.trim () !== '')
     if (!(token.trim ()))
       {
 	setSuggestionsVsbl (false)
@@ -71,15 +81,41 @@ const PostFormTagsArea: FC<Props> = ({ tags, setTags, errors, ...rest }) => {
       }
 
     setBounds ({ start, end })
-
-    const data = await apiGet<Tag[]> ('/tags/autocomplete', { locale, params: {
-	q: token,
-	nico: '0' } })
-    const nextSuggestions = data.filter (t => t.postCount > 0)
-    setSuggestions (nextSuggestions)
-    setSuggestionsVsbl (nextSuggestions.length > 0)
   }
 
+  useEffect (() => {
+    if (request.query.trim () === '')
+      return
+    const controller = new AbortController ()
+    let active = true
+    void (async () => {
+      try
+      {
+	const tags = await apiGet<Tag[]> ('/tags/autocomplete', {
+	    locale, signal: controller.signal, params: { q: request.query, nico: '0' } })
+	if (active)
+	{
+	  setResult ({ locale, request,
+	      tags: tags.filter (tag => tag.postCount > 0) })
+	}
+      }
+      catch
+      {
+	if (active)
+	  setResult ({ locale, request, tags: [] })
+      }
+    }) ()
+    return () => {
+      active = false
+      controller.abort ()
+    }
+  }, [request, locale])
+
+  useEffect (() => {
+    setSuggestionsVsbl (false)
+    setRequest ({ query: '' })
+  }, [locale])
+
   return (
       <FormField className="relative w-full" label={label ('tags')} messages={errors}>
 	{({ describedBy, invalid }) => (
@@ -93,7 +129,7 @@ const PostFormTagsArea: FC<Props> = ({ tags, setTags, errors, ...rest }) => {
 		  onChange={ev => setTags (ev.target.value)}
 		  onSelect={async (ev: SyntheticEvent<HTMLTextAreaElement>) => {
 		    const pos = (ev.target as HTMLTextAreaElement).selectionStart
-		    await recompute (pos)
+		    await recompute (pos, (ev.target as HTMLTextAreaElement).value)
 		  }}
 		  onFocus={() => setFocused (true)}
 		  onBlur={() => {

frontend/src/components/TagSearch.tsx

@@ -23,25 +23,57 @@ const TagSearch: FC = () => {
 
   const [activeIndex, setActiveIndex] = useState (-1)
   const [search, setSearch] = useState ('')
-  const [suggestions, setSuggestions] = useState<Tag[]> ([])
+  const [request, setRequest] = useState ({ query: '' })
+  const [result, setResult] = useState<{
+      locale: string
+      request: { query: string }
+      tags: Tag[] }> ({ locale, request, tags: [] })
+  const suggestions = result.locale === locale && result.request === request
+      ? result.tags : []
   const [suggestionsVsbl, setSuggestionsVsbl] = useState (false)
 
-  const whenChanged = async (ev: ChangeEvent<HTMLInputElement>) => {
-    setSearch (ev.target.value)
-
-    const q = ev.target.value.trim ().split (' ').at (-1)
-    if (!(q))
-      {
-	setSuggestions ([])
-	return
-      }
-
-    const data = await apiGet<Tag[]> ('/tags/autocomplete', { locale, params: { q } })
-    setSuggestions (data.filter (t => t.postCount > 0))
-    if (suggestions.length > 0)
-      setSuggestionsVsbl (true)
+  const whenChanged = (ev: ChangeEvent<HTMLInputElement>) => {
+    const value = ev.target.value
+    const query = value.trim ().split (' ').at (-1) ?? ''
+    setSearch (value)
+    setRequest ({ query })
+    setActiveIndex (-1)
+    setSuggestionsVsbl (query !== '')
   }
 
+  useEffect (() => {
+    if (request.query === '')
+      return
+    const controller = new AbortController ()
+    let active = true
+    void (async () => {
+      try
+      {
+	const tags = await apiGet<Tag[]> ('/tags/autocomplete', {
+	    locale, signal: controller.signal, params: { q: request.query } })
+	if (active)
+	{
+	  setResult ({ locale, request,
+	      tags: tags.filter (tag => tag.postCount > 0) })
+	}
+      }
+      catch
+      {
+	if (active)
+	  setResult ({ locale, request, tags: [] })
+      }
+    }) ()
+    return () => {
+      active = false
+      controller.abort ()
+    }
+  }, [request, locale])
+
+  useEffect (() => {
+    setActiveIndex (-1)
+    setSuggestionsVsbl (false)
+  }, [locale])
+
   const handleKeyDown = (ev: KeyboardEvent<HTMLInputElement>) => {
     switch (ev.key)
     {
@@ -85,6 +117,7 @@ const TagSearch: FC = () => {
 		match }))
 	    .toString () }`)
 	setSuggestionsVsbl (false)
+	setRequest ({ query: '' })
       }
   }
 
@@ -95,7 +128,8 @@ const TagSearch: FC = () => {
 	? ('not:' + tag.name)
 	: tag.name)
     setSearch (parts.join (' ') + ' ')
-    setSuggestions ([])
+    setRequest ({ query: '' })
+    setSuggestionsVsbl (false)
     setActiveIndex (-1)
   }
 
@@ -104,6 +138,9 @@ const TagSearch: FC = () => {
     const anyFlg = query.get ('match') === 'any'
     const tagsQuery = `${ query.get ('tags') ?? '' }${ anyFlg ? ' type:or' : '' }`
     setSearch (tagsQuery)
+    setRequest ({ query: '' })
+    setActiveIndex (-1)
+    setSuggestionsVsbl (false)
   }, [location.search])
 
   return (

frontend/src/components/WikiBody.tsx

@@ -35,15 +35,16 @@ const WikiBody: FC<Props> = ({ title, body, language = 'und' }) => {
   const missingPage = message ('missingPage', {
       url: `/wiki/new?title=${ encodeURIComponent (title) }` })
   const contentLanguage = body ? language : missingPage.language
-  const matchLanguage = contentLanguage === 'ain-Kana' ? 'ain' : contentLanguage
+  const matchLanguage = contentLanguage === 'und'
+      ? 'ja' : (contentLanguage === 'ain-Kana' ? 'ain' : contentLanguage)
   const { data } = useQuery ({
       enabled: Boolean (body),
       queryKey: wikiKeys.autolinkCandidates (matchLanguage, locale),
       queryFn: () => fetchWikiAutolinkCandidates (matchLanguage, locale) })
 
   const remarkPlugins = useMemo (
-      () => [() => remarkWikiAutoLink (data ?? [], matchLanguage), remarkGFM],
-      [data, matchLanguage])
+      () => [() => remarkWikiAutoLink (data ?? [], matchLanguage, locale), remarkGFM],
+      [data, matchLanguage, locale])
   const components = {
       ...((contentLanguage === 'ain' || contentLanguage === 'ain-Kana')
 	  ? ainuMDXComponents : { }),

frontend/src/components/common/TagInput.tsx

@@ -1,4 +1,4 @@
-import { useState } from 'react'
+import { useEffect, useState } from 'react'
 
 import { useLocale } from '@/lib/useLocale'
 import TagSearchBox from '@/components/TagSearchBox'
@@ -27,34 +27,67 @@ const TagInput: FC<Props> = ({
 }) => {
   const locale = useLocale ()
   const [activeIndex, setActiveIndex] = useState (-1)
-  const [suggestions, setSuggestions] = useState<Tag[]> ([])
+  const [request, setRequest] = useState ({ query: '' })
+  const [result, setResult] = useState<{
+      locale: string
+      includeNico: boolean
+      request: { query: string }
+      tags: Tag[] }> ({ locale, includeNico, request, tags: [] })
+  const suggestions = (result.locale === locale && result.includeNico === includeNico
+      && result.request === request
+      && request.query === value.trim ().split (' ').at (-1)) ? result.tags : []
   const [suggestionsVsbl, setSuggestionsVsbl] = useState (false)
 
   // TODO: TagSearch からのコピペのため，共通化を考へる．
-  const whenChanged = async (ev: ChangeEvent<HTMLInputElement>) => {
+  const whenChanged = (ev: ChangeEvent<HTMLInputElement>) => {
     setValue (ev.target.value)
-
-    const q = ev.target.value.trim ().split (' ').at (-1)
-    if (!(q))
-      {
-	setSuggestions ([])
-	return
-      }
-
-    const data = await apiGet<Tag[]> ('/tags/autocomplete', { locale, params: {
-	q,
-	nico: includeNico ? '1' : '0' } })
-    const nextSuggestions = data.filter (t => t.postCount > 0)
-    setSuggestions (nextSuggestions)
-    setSuggestionsVsbl (nextSuggestions.length > 0)
+    const query = ev.target.value.trim ().split (' ').at (-1) ?? ''
+    setRequest ({ query })
+    setActiveIndex (-1)
+    setSuggestionsVsbl (query !== '')
   }
 
+  useEffect (() => {
+    if (request.query === '')
+      return
+    const controller = new AbortController ()
+    let active = true
+    void (async () => {
+      try
+      {
+	const tags = await apiGet<Tag[]> ('/tags/autocomplete', {
+	    locale, signal: controller.signal,
+	    params: { q: request.query, nico: includeNico ? '1' : '0' } })
+	if (active)
+	{
+	  setResult ({ locale, includeNico, request,
+	      tags: tags.filter (tag => tag.postCount > 0) })
+	}
+      }
+      catch
+      {
+	if (active)
+	  setResult ({ locale, includeNico, request, tags: [] })
+      }
+    }) ()
+    return () => {
+      active = false
+      controller.abort ()
+    }
+  }, [request, locale, includeNico])
+
+  useEffect (() => {
+    setActiveIndex (-1)
+    setSuggestionsVsbl (false)
+    setRequest ({ query: '' })
+  }, [locale, includeNico])
+
   // TODO: TagSearch からのコピペのため，共通化を考へる．
   const handleTagSelect = (tag: Tag) => {
     const parts = value?.split (' ')
     parts[parts.length - 1] = tag.name
     setValue (parts.join (' ') + ' ')
-    setSuggestions ([])
+    setRequest ({ query: '' })
     setActiveIndex (-1)
   }
 

frontend/src/lib/locales.ts

@@ -35,6 +35,17 @@ export const localeFromPath = (pathname: string): LocaleCode | null => {
 }
 
 
+export const resolveViewingLocale = (
+    pathname: string,
+    routeLocale?: unknown,
+): LocaleCode =>
+    isLocaleCode (routeLocale) ? routeLocale : localeFromPath (pathname) ?? 'ja'
+
+
+export const currentViewingLocale = (): LocaleCode =>
+    resolveViewingLocale (typeof window === 'undefined' ? '' : window.location.pathname)
+
+
 export const unlocalisedPath = (pathname: string): string => {
   const locale = localeFromPath (pathname)
   return locale == null ? pathname : pathname.slice (locale.length + 1) || '/'

frontend/src/lib/prefetchers.ts

@@ -118,8 +118,9 @@ const prefetchWikiPageShow: Prefetcher = async (qc, url, locale) => {
 
   if (wikiPage?.body)
   {
-    const language = wikiPage.languageCode
+    const contentLanguage = wikiPage.languageCode
 	?? (wikiPage.resourceType === 'tag_description' ? localeLanguage (locale) : 'und')
+    const language = contentLanguage === 'und' ? 'ja' : contentLanguage
     await qc.prefetchQuery ({
 	queryKey: wikiKeys.autolinkCandidates (language, locale),
 	queryFn: () => fetchWikiAutolinkCandidates (language, locale) })

frontend/src/lib/queryKeys.ts

@@ -60,11 +60,11 @@ export const tagsKeys = {
     nicoIndex:    (
     p: FetchNicoTagsParams,
     locale: LocaleCode = 'ja',
-) => ['tags', locale, 'nico', 'index', p] as const,
+) => ['tags', 'nico', locale, 'index', p] as const,
     externalShow: (
     id: string,
     locale: LocaleCode = 'ja',
-) => ['tags', locale, 'nico', id] as const,
+) => ['tags', 'nico', locale, id] as const,
     show:         (
     name: string,
     locale: LocaleCode = 'ja',

frontend/src/lib/remark-wiki-autolink.ts

@@ -1,6 +1,7 @@
 import type { Content, Parent, Root, RootContent } from 'mdast'
 
 import type { WikiAutolinkCandidate } from '@/types'
+import type { LocaleCode } from '@/lib/locales'
 
 const escapeForRegExp = (s: string) => s.replace (/[.*+?^${}()|[\]\\]/g, '\\$&')
 
@@ -34,12 +35,14 @@ const edgeCharacter = (node: Content, first: boolean): string => {
 const remarkWikiAutoLink = (
     candidates: WikiAutolinkCandidate[],
     language: string,
+    locale: LocaleCode,
 ): ((tree: Root) => void) => {
   const targets = new Map<string, WikiAutolinkCandidate> ()
   const ambiguous = new Set<string> ()
   for (const candidate of candidates)
   {
-    if (candidate.languageCode !== language || candidate.name.length === 0)
+    if (candidate.languageCode !== language || candidate.localeCode !== locale
+	|| candidate.name.length === 0)
       continue
     const previous = targets.get (candidate.name)
     if (previous != null
@@ -89,7 +92,7 @@ const remarkWikiAutoLink = (
 	    parts.push ({ type: 'text', value: value.slice (last, start) })
 	  parts.push ({
 	      type: 'link',
-	      url: `/${candidate.localeCode}/wiki/${encodeURIComponent (candidate.resourceId)}`,
+	      url: `/${locale}/wiki/${encodeURIComponent (candidate.resourceId)}`,
 	      title: null,
 	      children: [{ type: 'text', value: match[0] }],
 	      data: { hProperties: { 'data-wiki': '1' } } })

frontend/src/lib/useLocale.ts

@@ -1,7 +1,7 @@
 import { useCallback } from 'react'
 import { useLocation, useNavigate, useParams } from 'react-router-dom'
 
-import { isLocaleCode, localeFromPath, localiseTo } from '@/lib/locales'
+import { localiseTo, resolveViewingLocale } from '@/lib/locales'
 
 import type { NavigateFunction, NavigateOptions, To } from 'react-router-dom'
 
@@ -11,7 +11,7 @@ import type { LocaleCode } from '@/lib/locales'
 export const useLocale = (): LocaleCode => {
   const { locale } = useParams ()
   const location = useLocation ()
-  return isLocaleCode (locale) ? locale : localeFromPath (location.pathname) ?? 'ja'
+  return resolveViewingLocale (location.pathname, locale)
 }
 
 

frontend/src/lib/utils.ts

@@ -2,6 +2,7 @@ import { clsx } from 'clsx'
 import { twMerge } from 'tailwind-merge'
 
 import { i18n } from '@/lib/i18n'
+import { currentViewingLocale } from '@/lib/locales'
 
 import type { ClassValue } from 'clsx'
 
@@ -14,37 +15,39 @@ export const toDate = (d: string | Date): Date => typeof d === 'string' ? new Da
 export const cn = (...inputs: ClassValue[]) => twMerge (clsx (...inputs))
 
 
-export const dateString = (
-    d:        string | Date,
-    unknown:  'month' | 'day' | 'hour' | 'minute' | 'second' | null = null): string =>
-    toDate (d).toLocaleString (
-	'ja-JP-u-ca-japanese',
-	{ era: 'long',
-	  year: 'numeric',
-	  month: (unknown === 'month' ? undefined : 'long'),
+type DatePrecision = 'month' | 'day' | 'hour' | 'minute' | 'second' | null
+
+const dateFormatters = new Map<DatePrecision, Intl.DateTimeFormat> ()
+let ainuDateFormatter: Intl.DateTimeFormat | null = null
+
+
+const formatDateString = (
+    date: Date,
+    unknown: DatePrecision,
+    locale: LocaleCode,
+): string => {
+  if (Number.isNaN (date.getTime ()))
+    return date.toString ()
+  if (locale === 'ja')
+  {
+    if (!dateFormatters.has (unknown))
+    {
+      dateFormatters.set (unknown, new Intl.DateTimeFormat ('ja-JP-u-ca-japanese', {
+	  era: 'long', year: 'numeric',
+	  month: unknown === 'month' ? undefined : 'long',
 	  day: unknown != null && ['month', 'day'].includes (unknown) ? undefined : 'numeric',
 	  weekday: unknown != null && ['month', 'day'].includes (unknown) ? undefined : 'short',
 	  hour: unknown == null || ['second', 'minute'].includes (unknown) ? 'numeric' : undefined,
 	  minute: unknown == null || unknown === 'second' ? 'numeric' : undefined,
-	  second: unknown == null ? 'numeric' : undefined })
-
-
-export const localisedDateString = (
-    value: string | Date,
-    locale: LocaleCode,
-    unknown: Parameters<typeof dateString>[1] = null,
-): string => {
-  if (locale === 'ja')
-    return dateString (value, unknown)
-
-  const date = toDate (value)
-  if (Number.isNaN (date.getTime ()))
-    return dateString (value, unknown)
-
-  const parts = new Intl.DateTimeFormat ('en-CA', {
+	  second: unknown == null ? 'numeric' : undefined }))
+    }
+    return dateFormatters.get (unknown)!.format (date)
+  }
+  ainuDateFormatter ??= new Intl.DateTimeFormat ('en-CA', {
       year: 'numeric', month: '2-digit', day: '2-digit',
       hour: '2-digit', minute: '2-digit', second: '2-digit',
-      hourCycle: 'h23' }).formatToParts (date)
+      hourCycle: 'h23' })
+  const parts = ainuDateFormatter.formatToParts (date)
   const part = (type: string) => parts.find (entry => entry.type === type)?.value ?? ''
   const omitDay = unknown != null && ['month', 'day'].includes (unknown)
   const dateParts = [part ('year'),
@@ -60,6 +63,20 @@ export const localisedDateString = (
 }
 
 
+export const dateString = (
+    value: string | Date,
+    unknown: DatePrecision = null,
+    locale?: LocaleCode,
+): string => formatDateString (toDate (value), unknown, locale ?? currentViewingLocale ())
+
+
+export const localisedDateString = (
+    value: string | Date,
+    locale: LocaleCode,
+    unknown: DatePrecision = null,
+): string => dateString (value, unknown, locale)
+
+
 export const originalCreatedAtString = (
     f:  string | Date | null,
     b:  string | Date | null,

frontend/src/locales/ain-Kana/history.json

@@ -1,6 +1,11 @@
 {
   "_untranslated": [
-    "exportPath"
+    "exportPath",
+    "restoreScope",
+    "nameChanges.title",
+    "nameChanges.script",
+    "nameChanges.automatic",
+    "nameChanges.certified"
   ],
   "exportPath": "export_path",
   "postTitle": "$t(tags:history)",
@@ -22,6 +27,13 @@
   "confirmTitle": "アホシピレ　エヌカㇻ",
   "confirmPost": "「{{name}}」　ウェㇽソン　{{version}}　ウン　アホシピレ　ヤ？\nピㇼカ　ヤ？",
   "confirmTag": "シロシ「{{name}}」　ウェㇽソン　{{version}}　ウン　アホシピレ　ヤ？\nピㇼカ　ヤ？",
+  "restoreScope": "名称・別名は現在表示中の言語だけを差し戻します。全言語の名称は復元しません。",
+  "nameChanges": {
+    "title": "言語別の変更",
+    "script": "文字体系",
+    "automatic": "自動生成",
+    "certified": "公証済み"
+  },
   "revert": "アホシピレ",
   "restored": "アホシピレ　オケレ！",
   "restoreFailed": "アホシピレ　カ　エアイカㇷ゚……",

frontend/src/locales/ja/history.json

@@ -19,6 +19,13 @@
   "confirmTitle": "差戻の確認",
   "confirmPost": "『{{name}}』を版 {{version}} に差戻します．\nよろしいですか?",
   "confirmTag": "タグ『{{name}}』を版 {{version}} に差戻します．\nよろしいですか?",
+  "restoreScope": "名称・別名は現在表示中の言語だけを差し戻します。全言語の名称は復元しません。",
+  "nameChanges": {
+    "title": "言語別の変更",
+    "script": "文字体系",
+    "automatic": "自動生成",
+    "certified": "公証済み"
+  },
   "revert": "差戻",
   "restored": "差戻しました．",
   "restoreFailed": "差戻に失敗……",

frontend/src/pages/TOSPage/index.tsx

@@ -14,7 +14,7 @@ const TOSPage = () => {
   const Terms = terms[`./${ locale }.mdx`] ?? terms['./ja.mdx']
   const language = terms[`./${ locale }.mdx`] != null ? locale : 'ja'
 
-  if (!terms)
+  if (!Terms)
     throw new Error ('TOSPage: ja.mdx not found')
 
   return (

frontend/src/pages/TOSPage/ja.mdx

@@ -1,7 +1,7 @@
 import MainArea from '@/components/layout/MainArea'
 import { dateString } from '@/lib/utils'
 
-export const lastUpdatedAt = dateString ('2026-04-12', 'hour')
+export const lastUpdatedAt = dateString ('2026-04-12', 'hour', 'ja')
 
 
 <MainArea>

frontend/src/pages/tags/TagHistoryPage.tsx

@@ -12,7 +12,7 @@ import PageHead from '@/components/common/PageHead'
 import { apiPut } from '@/lib/api'
 import { useDialogue } from '@/lib/dialogues/useDialogue'
 import { clientScrollBehaviour } from '@/lib/clientAnimation'
-import { postsKeys, tagsKeys } from '@/lib/queryKeys'
+import { postsKeys, tagsKeys, wikiKeys } from '@/lib/queryKeys'
 import { fetchTagChanges } from '@/lib/tags'
 import { useClientBehaviourSettings } from '@/lib/useClientBehaviourSettings'
 import { useUITranslation } from '@/lib/useUITranslation'
@@ -20,6 +20,36 @@ import { cn, localisedDateString } from '@/lib/utils'
 
 import type { FC, ReactNode } from 'react'
 
+import type { TagNameSnapshot } from '@/types'
+
+
+const renderNameSnapshot = (
+    snapshot: TagNameSnapshot,
+    language: string,
+    label: (key: string) => ReactNode,
+) => (
+    <div className="space-y-1">
+      <div>
+	{label ('name')}：
+	<span lang={language} className="inline-block whitespace-nowrap">{snapshot.name}</span>
+      </div>
+      {snapshot.scriptCode != null && (
+	  <div>{label ('nameChanges.script')}：<code>{snapshot.scriptCode}</code></div>)}
+      {snapshot.aliases.length > 0 && (
+	  <div>
+	    {label ('tags:aliases')}：
+	    {snapshot.aliases.map (alias => (
+		<span key={`${alias.name}:${alias.scriptCode}`} className="mr-2">
+		  <span lang={language} className="inline-block whitespace-nowrap">{alias.name}</span>
+		  {alias.scriptCode != null && <code> ({alias.scriptCode})</code>}
+		</span>))}
+	  </div>)}
+      {snapshot.autoGenerated != null && (
+	  <div>
+	    {label (snapshot.autoGenerated ? 'nameChanges.automatic' : 'nameChanges.certified')}
+	  </div>)}
+    </div>)
+
 
 const renderDiff = (
     diff: { current: string | null; prev: string | null },
@@ -119,7 +149,25 @@ const TagHistoryPage: FC = () => {
 			<tr key={`${ change.tagId }.${ change.versionNo }`}
 			    className={cn ('even:bg-gray-100 dark:even:bg-gray-700')}>
 			  <td className="p-2">{change.tagId}.{change.versionNo}</td>
-			  <td className="p-2 break-all">{renderDiff (change.name)}</td>
+			  <td className="p-2 break-all">
+			    {renderDiff (change.name)}
+			    {(change.nameChanges?.length ?? 0) > 0 && (
+				<div className="mt-2 space-y-2 text-sm">
+				  <div className="font-semibold">{label ('nameChanges.title')}</div>
+				  {change.nameChanges?.map (entry => (
+				      <div key={entry.languageCode}>
+					<code>{entry.languageCode}</code>
+					{entry.prev != null && (
+					    <div className="text-red-600 line-through dark:text-red-400">
+					      {renderNameSnapshot (entry.prev, entry.languageCode, label)}
+					    </div>)}
+					{entry.current != null && (
+					    <div className="text-green-600 underline dark:text-green-400">
+					      {renderNameSnapshot (entry.current, entry.languageCode, label)}
+					    </div>)}
+				      </div>))}
+				</div>)}
+			  </td>
 			  <td className="p-2 break-all">
 			    {renderDiff (change.category,
 				category => label (`common:categories.${category}`))}
@@ -193,9 +241,13 @@ const TagHistoryPage: FC = () => {
 
 				  if (!(await dialogue.confirm ({
 				      title: label ('confirmTitle'),
-				      description: label ('confirmTag', {
-					  name: change.name.current ?? '',
-					  version: change.versionNo }),
+				      description: (
+					  <>
+					    {label ('confirmTag', {
+						name: change.name.current ?? '', version: change.versionNo })}
+					    <br/>
+					    {label ('restoreScope')}
+					  </>),
 				      confirmText: label ('revert'),
 				      cancelText: label ('settings:actions.cancel'),
 				      closeLabel: label ('settings:actions.close') })))
@@ -225,6 +277,7 @@ const TagHistoryPage: FC = () => {
 
 				    qc.invalidateQueries ({ queryKey: postsKeys.root })
 				    qc.invalidateQueries ({ queryKey: tagsKeys.root })
+				    qc.invalidateQueries ({ queryKey: wikiKeys.root })
 				    toast ({ description: label ('restored') })
 				  }
 				  catch

frontend/src/pages/wiki/WikiDiffPage.tsx

@@ -21,21 +21,42 @@ const WikiDiffPage: FC = () => {
 
   const location = useLocation ()
 
-  const [diff, setDiff] = useState<WikiPageDiff | null> (null)
+  const [result, setResult] = useState<{
+      key: string
+      diff: WikiPageDiff } | null> (null)
 
   const query = new URLSearchParams (location.search)
   const from = query.get ('from')
   const to = query.get ('to')
+  const requestKey = JSON.stringify ([locale, id, from, to])
+  const diff = result?.key === requestKey ? result.diff : null
   const displayTitle = diff
       ? `${ diff.title }${ diff.deprecatedAt != null
 	  ? message ('shared:labels.deprecatedSuffix').text : '' }`
       : ''
 
   useEffect (() => {
+    const controller = new AbortController ()
+    let active = true
     void (async () => {
-      setDiff (await apiGet<WikiPageDiff> (`/wiki/${ id }/diff`, { locale, params: { from, to } }))
+      try
+      {
+	const diff = await apiGet<WikiPageDiff> (`/wiki/${ encodeURIComponent (id ?? '') }/diff`, {
+	    locale, signal: controller.signal, params: { from, to } })
+	if (active)
+	  setResult ({ key: requestKey, diff })
+      }
+      catch (error)
+      {
+	if (active)
+	  console.error (error)
+      }
     }) ()
-  }, [from, id, to, locale])
+    return () => {
+      active = false
+      controller.abort ()
+    }
+  }, [from, id, to, locale, requestKey])
 
   return (
       <MainArea>

frontend/src/pages/wiki/WikiEditPage.tsx

@@ -49,11 +49,16 @@ const WikiEditPage: FC<Props> = ({ user }) => {
 
   const [body, setBody] = useState ('')
   const [loading, setLoading] = useState (true)
+  const [loadedSource, setLoadedSource] = useState ('')
+  const source = `${locale}:${id}`
+  const pending = loading || loadedSource !== source
   const [title, setTitle] = useState ('')
   const { baseErrors, fieldErrors, clearValidationErrors, applyValidationError } =
       useValidationErrors<WikiFormField> ()
 
   const handleSubmit = async () => {
+    if (pending || !editable)
+      return
     clearValidationErrors ()
 
     const formData = new FormData ()
@@ -65,10 +70,11 @@ const WikiEditPage: FC<Props> = ({ user }) => {
       await apiPut (`/wiki/${ id }`, formData,
 		    { locale, headers: { 'Content-Type': 'multipart/form-data' } })
       qc.setQueryData (wikiKeys.show (title, { }, locale),
-		       (prev: WikiPage) => ({ ...prev, title, body }))
+		       (prev: WikiPage | undefined) =>
+			   prev == null ? prev : { ...prev, title, body })
       qc.invalidateQueries ({ queryKey: wikiKeys.root })
       toast ({ title: label ('shared:messages.postSuccess') })
-      navigate (`/wiki/${ title }`)
+      navigate (`/wiki/${ encodeURIComponent (title) }`)
     }
     catch (e)
     {
@@ -82,14 +88,33 @@ const WikiEditPage: FC<Props> = ({ user }) => {
     if (!(editable))
       return
 
+    const controller = new AbortController ()
+    let active = true
     void (async () => {
       setLoading (true)
-      const data = await apiGet<WikiPage> (`/wiki/${ id }`, { locale })
-      setTitle (data.title)
-      setBody (data.body)
-      setLoading (false)
+      try
+      {
+	const data = await apiGet<WikiPage> (`/wiki/${ encodeURIComponent (id ?? '') }`, {
+	    locale, signal: controller.signal })
+	if (active)
+	{
+	  setTitle (data.title)
+	  setBody (data.body)
+	  setLoadedSource (source)
+	  setLoading (false)
+	}
+      }
+      catch (error)
+      {
+	if (active)
+	  console.error (error)
+      }
     }) ()
-  }, [editable, id, locale])
+    return () => {
+      active = false
+      controller.abort ()
+    }
+  }, [editable, id, locale, source])
 
   if (!(editable))
     return <Forbidden/>
@@ -100,7 +125,7 @@ const WikiEditPage: FC<Props> = ({ user }) => {
 	<div className="max-w-xl mx-auto p-4 space-y-4">
 	  <h1 className="text-2xl font-bold mb-2">{label ('editPage')}</h1>
 
-	  {loading ? label ('common:loading') : (
+	  {pending ? label ('common:loading') : (
 	      <>
 		<FieldError messages={baseErrors}/>
 

frontend/src/pages/wiki/WikiHistoryPage.tsx

@@ -56,7 +56,7 @@ const WikiHistoryPage: FC = () => {
 		  </td>
 		  <td className="p-2">
 		    <PrefetchLink
-			to={`/wiki/${ encodeURIComponent (change.wikiPage.title) }?version=${ change.revisionId }`}>
+			to={`/wiki/${ change.wikiPage.id }?version=${ change.revisionId }`}>
 		      {change.wikiPage.title}
 		    </PrefetchLink>
 		    {change.wikiPage.deprecatedAt != null && label ('shared:labels.deprecatedSuffix')}

frontend/src/types.ts

@@ -367,10 +367,22 @@ export type Tag = {
     children?:      Tag[]
     matchedAlias?:  string | null }
 
+export type TagNameSnapshot = {
+    name: string | null
+    scriptCode: string | null
+    autoGenerated: boolean | null
+    aliases: { name: string; scriptCode: string | null }[] }
+
+export type TagNameChange = {
+    languageCode: string
+    current: TagNameSnapshot | null
+    prev: TagNameSnapshot | null }
+
 export type TagVersion = {
     tagId:                  number
     versionNo:              number
     eventType:              'create' | 'update' | 'discard' | 'restore'
+    nameChanges?:           TagNameChange[]
     name:                   { current: string | null; prev: string | null }
     category:               { current: Category; prev: Category | null }
     deprecatedAt:           { current: string | null; prev: string | null }