discourse/app/controllers/posts_controller.rb
Alan Guo Xiang Tan bfc3132bb2
SECURITY: Impose a upper bound on limit params in various controllers
What is the problem here?

In multiple controllers, we are accepting a `limit` params but do not
impose any upper bound on the values being accepted. Without an upper
bound, we may be allowing arbituary users from generating DB queries
which may end up exhausing the resources on the server.

What is the fix here?

A new `fetch_limit_from_params` helper method is introduced in
`ApplicationController` that can be used by controller actions to safely
get the limit from the params as a default limit and maximum limit has
to be set. When an invalid limit params is encountered, the server will
respond with the 400 response code.
2023-07-28 12:53:46 +01:00

971 lines
28 KiB
Ruby

# frozen_string_literal: true
class PostsController < ApplicationController
# Bug with Rails 7+
# see https://github.com/rails/rails/issues/44867
self._flash_types -= [:notice]
requires_login except: %i[
show
replies
by_number
by_date
short_link
reply_history
reply_ids
revisions
latest_revision
expand_embed
markdown_id
markdown_num
cooked
latest
user_posts_feed
]
skip_before_action :preload_json,
:check_xhr,
only: %i[markdown_id markdown_num short_link latest user_posts_feed]
MARKDOWN_TOPIC_PAGE_SIZE ||= 100
def markdown_id
markdown Post.find_by(id: params[:id].to_i)
end
def markdown_num
if params[:revision].present?
post_revision = find_post_revision_from_topic_id
render plain: post_revision.modifications[:raw].last
elsif params[:post_number].present?
markdown Post.find_by(
topic_id: params[:topic_id].to_i,
post_number: params[:post_number].to_i,
)
else
opts = params.slice(:page)
opts[:limit] = MARKDOWN_TOPIC_PAGE_SIZE
topic_view = TopicView.new(params[:topic_id], current_user, opts)
content = topic_view.posts.map { |p| <<~MD }
#{p.user.username} | #{p.updated_at} | ##{p.post_number}
#{p.raw}
-------------------------
MD
render plain: content.join
end
end
def latest
params.permit(:before)
last_post_id = params[:before].to_i
last_post_id = Post.last.id if last_post_id <= 0
if params[:id] == "private_posts"
raise Discourse::NotFound if current_user.nil?
posts =
Post
.private_posts
.order(created_at: :desc)
.where("posts.id <= ?", last_post_id)
.where("posts.id > ?", last_post_id - 50)
.includes(topic: :category)
.includes(user: %i[primary_group flair_group])
.includes(:reply_to_user)
.limit(50)
rss_description = I18n.t("rss_description.private_posts")
else
posts =
Post
.public_posts
.visible
.where(post_type: Post.types[:regular])
.order(created_at: :desc)
.where("posts.id <= ?", last_post_id)
.where("posts.id > ?", last_post_id - 50)
.includes(topic: :category)
.includes(user: %i[primary_group flair_group])
.includes(:reply_to_user)
.limit(50)
rss_description = I18n.t("rss_description.posts")
@use_canonical = true
end
# Remove posts the user doesn't have permission to see
# This isn't leaking any information we weren't already through the post ID numbers
posts = posts.reject { |post| !guardian.can_see?(post) || post.topic.blank? }
counts = PostAction.counts_for(posts, current_user)
respond_to do |format|
format.rss do
@posts = posts
@title = "#{SiteSetting.title} - #{rss_description}"
@link = Discourse.base_url
@description = rss_description
render "posts/latest", formats: [:rss]
end
format.json do
render_json_dump(
serialize_data(
posts,
PostSerializer,
scope: guardian,
root: params[:id],
add_raw: true,
add_title: true,
all_post_actions: counts,
),
)
end
end
end
def user_posts_feed
params.require(:username)
user = fetch_user_from_params
raise Discourse::NotFound unless guardian.can_see_profile?(user)
posts =
Post
.public_posts
.visible
.where(user_id: user.id)
.where(post_type: Post.types[:regular])
.order(created_at: :desc)
.includes(:user)
.includes(topic: :category)
.limit(50)
posts = posts.reject { |post| !guardian.can_see?(post) || post.topic.blank? }
respond_to do |format|
format.rss do
@posts = posts
@title =
"#{SiteSetting.title} - #{I18n.t("rss_description.user_posts", username: user.username)}"
@link = "#{user.full_url}/activity"
@description = I18n.t("rss_description.user_posts", username: user.username)
render "posts/latest", formats: [:rss]
end
format.json do
render_json_dump(serialize_data(posts, PostSerializer, scope: guardian, add_excerpt: true))
end
end
end
def cooked
render json: { cooked: find_post_from_params.cooked }
end
def raw_email
params.require(:id)
post = Post.unscoped.find(params[:id].to_i)
guardian.ensure_can_view_raw_email!(post)
text, html = Email.extract_parts(post.raw_email)
render json: { raw_email: post.raw_email, text_part: text, html_part: html }
end
def short_link
post = Post.find_by(id: params[:post_id].to_i)
raise Discourse::NotFound unless post
# Stuff the user in the request object, because that's what IncomingLink wants
if params[:user_id]
user = User.find_by(id: params[:user_id].to_i)
request["u"] = user.username_lower if user
end
guardian.ensure_can_see!(post)
redirect_to path(post.url)
end
def create
manager_params = create_params
manager_params[:first_post_checks] = !is_api?
manager_params[:advance_draft] = !is_api?
manager = NewPostManager.new(current_user, manager_params)
json =
if is_api?
memoized_payload =
DistributedMemoizer.memoize(signature_for(manager_params), 120) do
MultiJson.dump(serialize_data(manager.perform, NewPostResultSerializer, root: false))
end
JSON.parse(memoized_payload)
else
serialize_data(manager.perform, NewPostResultSerializer, root: false)
end
backwards_compatible_json(json)
end
def update
params.require(:post)
post = Post.where(id: params[:id])
post = post.with_deleted if guardian.is_staff?
post = post.first
raise Discourse::NotFound if post.blank?
post.image_sizes = params[:image_sizes] if params[:image_sizes].present?
if !guardian.public_send("can_edit?", post) && post.user_id == current_user.id &&
post.edit_time_limit_expired?(current_user)
return render_json_error(I18n.t("too_late_to_edit"))
end
guardian.ensure_can_edit!(post)
changes = { raw: params[:post][:raw], edit_reason: params[:post][:edit_reason] }
Post.plugin_permitted_update_params.keys.each { |param| changes[param] = params[:post][param] }
raw_old = params[:post][:raw_old]
if raw_old.present? && raw_old != post.raw
return render_json_error(I18n.t("edit_conflict"), status: 409)
end
# to stay consistent with the create api, we allow for title & category changes here
if post.is_first_post?
changes[:title] = params[:title] if params[:title]
changes[:category_id] = params[:post][:category_id] if params[:post][:category_id]
if changes[:category_id] && changes[:category_id].to_i != post.topic.category_id.to_i
category = Category.find_by(id: changes[:category_id])
if category || (changes[:category_id].to_i == 0)
guardian.ensure_can_move_topic_to_category!(category)
else
return render_json_error(I18n.t("category.errors.not_found"))
end
end
end
# We don't need to validate edits to small action posts by staff
opts = {}
if post.post_type == Post.types[:small_action] && current_user.staff?
opts[:skip_validations] = true
end
topic = post.topic
topic = Topic.with_deleted.find(post.topic_id) if guardian.is_staff?
revisor = PostRevisor.new(post, topic)
revisor.revise!(current_user, changes, opts)
return render_json_error(post) if post.errors.present?
return render_json_error(topic) if topic.errors.present?
post_serializer = PostSerializer.new(post, scope: guardian, root: false, add_raw: true)
post_serializer.draft_sequence = DraftSequence.current(current_user, topic.draft_key)
link_counts = TopicLink.counts_for(guardian, topic, [post])
post_serializer.single_post_link_counts = link_counts[post.id] if link_counts.present?
result = { post: post_serializer.as_json }
if revisor.category_changed.present?
result[:category] = BasicCategorySerializer.new(
revisor.category_changed,
scope: guardian,
root: false,
).as_json
end
render_json_dump(result)
end
def show
post = find_post_from_params
display_post(post)
end
def by_number
post = find_post_from_params_by_number
display_post(post)
end
def by_date
post = find_post_from_params_by_date
display_post(post)
end
def reply_history
post = find_post_from_params
reply_history = post.reply_history(params[:max_replies].to_i, guardian)
user_custom_fields = {}
if (added_fields = User.allowed_user_custom_fields(guardian)).present?
user_custom_fields = User.custom_fields_for_ids(reply_history.pluck(:user_id), added_fields)
end
render_serialized(reply_history, PostSerializer, user_custom_fields: user_custom_fields)
end
def reply_ids
post = find_post_from_params
render json: post.reply_ids(guardian).to_json
end
def all_reply_ids
Discourse.deprecate("/posts/:id/reply-ids/all is deprecated.", drop_from: "3.0")
post = find_post_from_params
render json: post.reply_ids(guardian, only_replies_to_single_post: false).to_json
end
def destroy
post = find_post_from_params
force_destroy = ActiveModel::Type::Boolean.new.cast(params[:force_destroy])
if force_destroy
if !guardian.can_permanently_delete?(post)
return render_json_error post.cannot_permanently_delete_reason(current_user), status: 403
end
else
guardian.ensure_can_delete!(post)
end
unless guardian.can_moderate_topic?(post.topic)
RateLimiter.new(
current_user,
"delete_post_per_min",
SiteSetting.max_post_deletions_per_minute,
1.minute,
).performed!
RateLimiter.new(
current_user,
"delete_post_per_day",
SiteSetting.max_post_deletions_per_day,
1.day,
).performed!
end
PostDestroyer.new(
current_user,
post,
context: params[:context],
force_destroy: force_destroy,
).destroy
render body: nil
end
def expand_embed
render json: { cooked: TopicEmbed.expanded_for(find_post_from_params) }
rescue StandardError
render_json_error I18n.t("errors.embed.load_from_remote")
end
def recover
post = find_post_from_params
guardian.ensure_can_recover_post!(post)
unless guardian.can_moderate_topic?(post.topic)
RateLimiter.new(
current_user,
"delete_post_per_min",
SiteSetting.max_post_deletions_per_minute,
1.minute,
).performed!
RateLimiter.new(
current_user,
"delete_post_per_day",
SiteSetting.max_post_deletions_per_day,
1.day,
).performed!
end
destroyer = PostDestroyer.new(current_user, post)
destroyer.recover
post.reload
render_post_json(post)
end
def destroy_many
params.require(:post_ids)
agree_with_first_reply_flag = (params[:agree_with_first_reply_flag] || true).to_s == "true"
posts = Post.where(id: post_ids_including_replies).order(:id)
raise Discourse::InvalidParameters.new(:post_ids) if posts.blank?
# Make sure we can delete the posts
posts.each { |p| guardian.ensure_can_delete!(p) }
Post.transaction do
posts.each_with_index do |p, i|
PostDestroyer.new(
current_user,
p,
defer_flags: !(agree_with_first_reply_flag && i == 0),
).destroy
end
end
render body: nil
end
def merge_posts
params.require(:post_ids)
posts = Post.where(id: params[:post_ids]).order(:id)
raise Discourse::InvalidParameters.new(:post_ids) if posts.pluck(:id) == params[:post_ids]
PostMerger.new(current_user, posts).merge
render body: nil
rescue PostMerger::CannotMergeError => e
render_json_error(e.message)
end
# Direct replies to this post
def replies
post = find_post_from_params
replies = post.replies.secured(guardian)
user_custom_fields = {}
if (added_fields = User.allowed_user_custom_fields(guardian)).present?
user_custom_fields = User.custom_fields_for_ids(replies.pluck(:user_id), added_fields)
end
render_serialized(replies, PostSerializer, user_custom_fields: user_custom_fields)
end
def revisions
post = find_post_from_params
raise Discourse::NotFound if post.hidden && !guardian.can_view_hidden_post_revisions?
post_revision = find_post_revision_from_params
post_revision_serializer =
PostRevisionSerializer.new(post_revision, scope: guardian, root: false)
render_json_dump(post_revision_serializer)
end
def latest_revision
post = find_post_from_params
raise Discourse::NotFound if post.hidden && !guardian.can_view_hidden_post_revisions?
post_revision = find_latest_post_revision_from_params
post_revision_serializer =
PostRevisionSerializer.new(post_revision, scope: guardian, root: false)
render_json_dump(post_revision_serializer)
end
def hide_revision
post_revision = find_post_revision_from_params
guardian.ensure_can_hide_post_revision!(post_revision)
post_revision.hide!
post = find_post_from_params
post.public_version -= 1
post.save
render body: nil
end
def permanently_delete_revisions
guardian.ensure_can_permanently_delete_post_revisions!
post = find_post_from_params
raise Discourse::InvalidParameters.new(:post) if post.blank?
raise Discourse::NotFound unless post.revisions.present?
RateLimiter.new(
current_user,
"admin_permanently_delete_post_revisions",
20,
1.minute,
apply_limit_to_staff: true,
).performed!
ActiveRecord::Base.transaction do
updated_at = Time.zone.now
post.revisions.destroy_all
post.update(version: 1, public_version: 1, last_version_at: updated_at)
StaffActionLogger.new(current_user).log_permanently_delete_post_revisions(post)
end
post.rebake!
render body: nil
end
def show_revision
post_revision = find_post_revision_from_params
guardian.ensure_can_show_post_revision!(post_revision)
post_revision.show!
post = find_post_from_params
post.public_version += 1
post.save
render body: nil
end
def revert
raise Discourse::NotFound unless guardian.is_staff?
post_id = params[:id] || params[:post_id]
revision = params[:revision].to_i
raise Discourse::InvalidParameters.new(:revision) if revision < 2
post_revision = PostRevision.find_by(post_id: post_id, number: revision)
raise Discourse::NotFound unless post_revision
post = find_post_from_params
raise Discourse::NotFound if post.blank?
post_revision.post = post
guardian.ensure_can_see!(post_revision)
guardian.ensure_can_edit!(post)
if post_revision.modifications["raw"].blank? && post_revision.modifications["title"].blank? &&
post_revision.modifications["category_id"].blank?
return render_json_error(I18n.t("revert_version_same"))
end
topic = Topic.with_deleted.find(post.topic_id)
changes = {}
changes[:raw] = post_revision.modifications["raw"][0] if post_revision.modifications[
"raw"
].present? && post_revision.modifications["raw"][0] != post.raw
if post.is_first_post?
changes[:title] = post_revision.modifications["title"][0] if post_revision.modifications[
"title"
].present? && post_revision.modifications["title"][0] != topic.title
changes[:category_id] = post_revision.modifications["category_id"][
0
] if post_revision.modifications["category_id"].present? &&
post_revision.modifications["category_id"][0] != topic.category.id
end
return render_json_error(I18n.t("revert_version_same")) if changes.length <= 0
changes[:edit_reason] = I18n.with_locale(SiteSetting.default_locale) do
I18n.t("reverted_to_version", version: post_revision.number.to_i - 1)
end
revisor = PostRevisor.new(post, topic)
revisor.revise!(current_user, changes)
return render_json_error(post) if post.errors.present?
return render_json_error(topic) if topic.errors.present?
post_serializer = PostSerializer.new(post, scope: guardian, root: false)
post_serializer.draft_sequence = DraftSequence.current(current_user, topic.draft_key)
link_counts = TopicLink.counts_for(guardian, topic, [post])
post_serializer.single_post_link_counts = link_counts[post.id] if link_counts.present?
result = { post: post_serializer.as_json }
if post.is_first_post?
result[:topic] = BasicTopicSerializer.new(
topic,
scope: guardian,
root: false,
).as_json if post_revision.modifications["title"].present?
result[:category_id] = post_revision.modifications["category_id"][
0
] if post_revision.modifications["category_id"].present?
end
render_json_dump(result)
end
def locked
post = find_post_from_params
locker = PostLocker.new(post, current_user)
params[:locked] === "true" ? locker.lock : locker.unlock
render_json_dump(locked: post.locked?)
end
def notice
post = find_post_from_params
raise Discourse::NotFound unless guardian.can_edit_staff_notes?(post.topic)
old_notice = post.custom_fields[Post::NOTICE]
if params[:notice].present?
post.custom_fields[Post::NOTICE] = {
type: Post.notices[:custom],
raw: params[:notice],
cooked: PrettyText.cook(params[:notice], features: { onebox: false }),
}
else
post.custom_fields.delete(Post::NOTICE)
end
post.save_custom_fields
StaffActionLogger.new(current_user).log_post_staff_note(
post,
old_value: old_notice&.[]("raw"),
new_value: params[:notice],
)
render body: nil
end
def destroy_bookmark
params.require(:post_id)
bookmark_id =
Bookmark.where(
bookmarkable_id: params[:post_id],
bookmarkable_type: "Post",
user_id: current_user.id,
).pick(:id)
destroyed_bookmark = BookmarkManager.new(current_user).destroy(bookmark_id)
render json:
success_json.merge(BookmarkManager.bookmark_metadata(destroyed_bookmark, current_user))
end
def wiki
post = find_post_from_params
params.require(:wiki)
guardian.ensure_can_wiki!(post)
post.revise(current_user, wiki: params[:wiki])
render body: nil
end
def post_type
guardian.ensure_can_change_post_type!
post = find_post_from_params
params.require(:post_type)
raise Discourse::InvalidParameters.new(:post_type) if Post.types[params[:post_type].to_i].blank?
post.revise(current_user, post_type: params[:post_type].to_i)
render body: nil
end
def rebake
guardian.ensure_can_rebake!
post = find_post_from_params
post.rebake!(invalidate_oneboxes: true, invalidate_broken_images: true)
render body: nil
end
def unhide
post = find_post_from_params
guardian.ensure_can_unhide!(post)
post.unhide!
render body: nil
end
DELETED_POSTS_MAX_LIMIT = 100
def deleted_posts
params.permit(:offset, :limit)
guardian.ensure_can_see_deleted_posts!
user = fetch_user_from_params
offset = [params[:offset].to_i, 0].max
limit = fetch_limit_from_params(default: 60, max: DELETED_POSTS_MAX_LIMIT)
posts = user_posts(guardian, user.id, offset: offset, limit: limit).where.not(deleted_at: nil)
render_serialized(posts, AdminUserActionSerializer)
end
def pending
params.require(:username)
user = fetch_user_from_params
raise Discourse::NotFound unless guardian.can_edit_user?(user)
render_serialized(
user.pending_posts.order(created_at: :desc),
PendingPostSerializer,
root: :pending_posts,
)
end
protected
def markdown(post)
if post && guardian.can_see?(post)
render plain: post.raw
else
raise Discourse::NotFound
end
end
# We can't break the API for making posts. The new, queue supporting API
# doesn't return the post as the root JSON object, but as a nested object.
# If a param is present it uses that result structure.
def backwards_compatible_json(json_obj)
json_obj.symbolize_keys!
success = json_obj[:success]
if params[:nested_post].blank? && json_obj[:errors].blank? &&
json_obj[:action].to_s != "enqueued"
json_obj = json_obj[:post]
end
if !success && GlobalSetting.try(:verbose_api_logging) && (is_api? || is_user_api?)
Rails.logger.error "Error creating post via API:\n\n#{json_obj.inspect}"
end
render json: json_obj, status: (!!success) ? 200 : 422
end
def find_post_revision_from_params
post_id = params[:id] || params[:post_id]
revision = params[:revision].to_i
raise Discourse::InvalidParameters.new(:revision) if revision < 2
post_revision = PostRevision.find_by(post_id: post_id, number: revision)
raise Discourse::NotFound unless post_revision
post_revision.post = find_post_from_params
guardian.ensure_can_see!(post_revision)
post_revision
end
def find_latest_post_revision_from_params
post_id = params[:id] || params[:post_id]
finder = PostRevision.where(post_id: post_id).order(:number)
finder = finder.where(hidden: false) unless guardian.is_staff?
post_revision = finder.last
raise Discourse::NotFound unless post_revision
post_revision.post = find_post_from_params
guardian.ensure_can_see!(post_revision)
post_revision
end
def find_post_revision_from_topic_id
post =
Post.find_by(topic_id: params[:topic_id].to_i, post_number: (params[:post_number] || 1).to_i)
raise Discourse::NotFound unless guardian.can_see?(post)
revision = params[:revision].to_i
raise Discourse::NotFound if revision < 2
post_revision = PostRevision.find_by(post_id: post.id, number: revision)
raise Discourse::NotFound unless post_revision
post_revision.post = post
guardian.ensure_can_see!(post_revision)
post_revision
end
private
def user_posts(guardian, user_id, opts)
# Topic.unscoped is necessary to remove the default deleted_at: nil scope
posts =
Topic.unscoped do
Post
.includes(:user, :topic, :deleted_by, :user_actions)
.where(user_id: user_id)
.with_deleted
.order(created_at: :desc)
end
if guardian.user.moderator?
# Awful hack, but you can't seem to remove the `default_scope` when joining
# So instead I grab the topics separately
topic_ids = posts.dup.pluck(:topic_id)
topics = Topic.where(id: topic_ids).with_deleted.where.not(archetype: "private_message")
topics = topics.secured(guardian)
posts = posts.where(topic_id: topics)
end
posts.offset(opts[:offset]).limit(opts[:limit])
end
def create_params
permitted = %i[
raw
topic_id
archetype
category
target_recipients
reply_to_post_number
auto_track
typing_duration_msecs
composer_open_duration_msecs
visible
draft_key
]
Post.plugin_permitted_create_params.each do |key, value|
if value[:plugin].enabled?
permitted << case value[:type]
when :string
key.to_sym
when :array
{ key => [] }
when :hash
{ key => {} }
end
end
end
# param munging for WordPress
params[:auto_track] = !(params[:auto_track].to_s == "false") if params[:auto_track]
params[:visible] = (params[:unlist_topic].to_s == "false") if params[:unlist_topic]
if is_api?
# php seems to be sending this incorrectly, don't fight with it
params[:skip_validations] = params[:skip_validations].to_s == "true"
permitted << :skip_validations
params[:import_mode] = params[:import_mode].to_s == "true"
permitted << :import_mode
# We allow `embed_url` via the API
permitted << :embed_url
# We allow `created_at` via the API
permitted << :created_at
# We allow `external_id` via the API
permitted << :external_id
end
result =
params
.permit(*permitted)
.tap do |allowed|
allowed[:image_sizes] = params[:image_sizes]
# TODO this does not feel right, we should name what meta_data is allowed
allowed[:meta_data] = params[:meta_data]
end
# Staff are allowed to pass `is_warning`
if current_user.staff?
params.permit(:is_warning)
result[:is_warning] = (params[:is_warning] == "true")
else
result[:is_warning] = false
end
if params[:no_bump] == "true"
raise Discourse::InvalidParameters.new(:no_bump) unless guardian.can_skip_bump?
result[:no_bump] = true
end
if params[:shared_draft] == "true"
raise Discourse::InvalidParameters.new(:shared_draft) unless guardian.can_create_shared_draft?
result[:shared_draft] = true
end
if params[:whisper] == "true"
unless guardian.can_create_whisper?
raise Discourse::InvalidAccess.new(
"invalid_whisper_access",
nil,
custom_message: "invalid_whisper_access",
)
end
result[:post_type] = Post.types[:whisper]
end
PostRevisor.tracked_topic_fields.each_key do |f|
params.permit(f => [])
result[f] = params[f] if params.has_key?(f)
end
# Stuff we can use in spam prevention plugins
result[:ip_address] = request.remote_ip
result[:user_agent] = request.user_agent
result[:referrer] = request.env["HTTP_REFERER"]
recipients = result[:target_recipients]
if recipients
recipients = recipients.split(",").map(&:downcase)
groups =
Group.messageable(current_user).where("lower(name) in (?)", recipients).pluck("lower(name)")
recipients -= groups
emails = recipients.select { |user| user.match(/@/) }
recipients -= emails
result[:target_usernames] = recipients.join(",")
result[:target_emails] = emails.join(",")
result[:target_group_names] = groups.join(",")
end
result.permit!
result.to_h
end
def signature_for(args)
+"post##" << Digest::SHA1.hexdigest(
args
.to_h
.to_a
.concat([["user", current_user.id]])
.sort { |x, y| x[0] <=> y[0] }
.join { |x, y| "#{x}:#{y}" },
)
end
def display_post(post)
post.revert_to(params[:version].to_i) if params[:version].present?
render_post_json(post)
end
def find_post_from_params
by_id_finder = Post.where(id: params[:id] || params[:post_id])
find_post_using(by_id_finder)
end
def find_post_from_params_by_number
by_number_finder = Post.where(topic_id: params[:topic_id], post_number: params[:post_number])
find_post_using(by_number_finder)
end
def find_post_from_params_by_date
by_date_finder =
TopicView
.new(params[:topic_id], current_user)
.filtered_posts
.where("created_at >= ?", Time.zone.parse(params[:date]))
.order("created_at ASC")
.limit(1)
find_post_using(by_date_finder)
end
def find_post_using(finder)
# A deleted post can be seen by staff or a category group moderator for the topic.
# But we must find the deleted post to determine which category it belongs to, so
# we must find.with_deleted
post = finder.with_deleted.first
raise Discourse::NotFound unless post
post.topic = Topic.with_deleted.find_by(id: post.topic_id)
if !post.topic ||
(
(post.deleted_at.present? || post.topic.deleted_at.present?) &&
!guardian.can_moderate_topic?(post.topic)
)
raise Discourse::NotFound
end
guardian.ensure_can_see!(post)
post
end
end