From f9af90c5aa42169b929f4ac6b352730b4d3416c7 Mon Sep 17 00:00:00 2001
From: Egor <egor@kislitsyn.com>
Date: Fri, 12 Apr 2019 19:25:53 +0000
Subject: [PATCH] Revert "simplify mentions escape"

This reverts commit f3e06a1030636f24f7129dd93bb9780e67fb7de1.
---
 lib/pleroma/formatter.ex            | 42 +++++++++++++++++++++++++++++--------
 lib/pleroma/web/common_api/utils.ex |  5 ++---
 mix.exs                             |  2 +-
 mix.lock                            |  2 +-
 4 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/lib/pleroma/formatter.ex b/lib/pleroma/formatter.ex
index 8ea9dbd38..dab8910c1 100644
--- a/lib/pleroma/formatter.ex
+++ b/lib/pleroma/formatter.ex
@@ -9,20 +9,31 @@ defmodule Pleroma.Formatter do
   alias Pleroma.Web.MediaProxy
 
   @safe_mention_regex ~r/^(\s*(?<mentions>@.+?\s+)+)(?<rest>.*)/
+  @link_regex ~r"((?:http(s)?:\/\/)?[\w.-]+(?:\.[\w\.-]+)+[\w\-\._~%:/?#[\]@!\$&'\(\)\*\+,;=.]+)|[0-9a-z+\-\.]+:[0-9a-z$-_.+!*'(),]+"ui
   @markdown_characters_regex ~r/(`|\*|_|{|}|[|]|\(|\)|#|\+|-|\.|!)/
-  @link_regex ~r{((?:http(s)?:\/\/)?[\w.-]+(?:\.[\w\.-]+)+[\w\-\._~%:/?#[\]@!\$&'\(\)\*\+,;=.]+)|[0-9a-z+\-\.]+:[0-9a-z$-_.+!*'(),]+}ui
-  # credo:disable-for-previous-line Credo.Check.Readability.MaxLineLength
 
   @auto_linker_config hashtag: true,
                       hashtag_handler: &Pleroma.Formatter.hashtag_handler/4,
                       mention: true,
                       mention_handler: &Pleroma.Formatter.mention_handler/4
 
+  def escape_mention_handler("@" <> nickname = mention, buffer, _, _) do
+    case User.get_cached_by_nickname(nickname) do
+      %User{} ->
+        # escape markdown characters with `\\`
+        # (we don't want something like @user__name to be parsed by markdown)
+        String.replace(mention, @markdown_characters_regex, "\\\\\\1")
+
+      _ ->
+        buffer
+    end
+  end
+
   def mention_handler("@" <> nickname, buffer, opts, acc) do
     case User.get_cached_by_nickname(nickname) do
       %User{id: id} = user ->
         ap_id = get_ap_id(user)
-        nickname_text = get_nickname_text(nickname, opts) |> maybe_escape(opts)
+        nickname_text = get_nickname_text(nickname, opts)
 
         link =
           "<span class='h-card'><a data-user='#{id}' class='u-url mention' href='#{ap_id}'>@<span>#{
@@ -70,6 +81,25 @@ defmodule Pleroma.Formatter do
     end
   end
 
+  @doc """
+  Escapes a special characters in mention names.
+  """
+  def mentions_escape(text, options \\ []) do
+    options =
+      Keyword.merge(options,
+        mention: true,
+        url: false,
+        mention_handler: &Pleroma.Formatter.escape_mention_handler/4
+      )
+
+    if options[:safe_mention] && Regex.named_captures(@safe_mention_regex, text) do
+      %{"mentions" => mentions, "rest" => rest} = Regex.named_captures(@safe_mention_regex, text)
+      AutoLinker.link(mentions, options) <> AutoLinker.link(rest, options)
+    else
+      AutoLinker.link(text, options)
+    end
+  end
+
   def emojify(text) do
     emojify(text, Emoji.get_all())
   end
@@ -140,10 +170,4 @@ defmodule Pleroma.Formatter do
 
   defp get_nickname_text(nickname, %{mentions_format: :full}), do: User.full_nickname(nickname)
   defp get_nickname_text(nickname, _), do: User.local_nickname(nickname)
-
-  defp maybe_escape(str, %{mentions_escape: true}) do
-    String.replace(str, @markdown_characters_regex, "\\\\\\1")
-  end
-
-  defp maybe_escape(str, _), do: str
 end
diff --git a/lib/pleroma/web/common_api/utils.ex b/lib/pleroma/web/common_api/utils.ex
index 7b9f0ea06..58a561a40 100644
--- a/lib/pleroma/web/common_api/utils.ex
+++ b/lib/pleroma/web/common_api/utils.ex
@@ -195,11 +195,10 @@ defmodule Pleroma.Web.CommonAPI.Utils do
   Formatting text to markdown.
   """
   def format_input(text, "text/markdown", options) do
-    options = Keyword.put(options, :mentions_escape, true)
-
     text
+    |> Formatter.mentions_escape(options)
+    |> Earmark.as_html!()
     |> Formatter.linkify(options)
-    |> (fn {text, mentions, tags} -> {Earmark.as_html!(text), mentions, tags} end).()
     |> Formatter.html_escape("text/html")
   end
 
diff --git a/mix.exs b/mix.exs
index 26a03b70b..e0c870fa7 100644
--- a/mix.exs
+++ b/mix.exs
@@ -101,7 +101,7 @@ defmodule Pleroma.Mixfile do
       {:ueberauth, "~> 0.4"},
       {:auto_linker,
        git: "https://git.pleroma.social/pleroma/auto_linker.git",
-       ref: "479dd343f4e563ff91215c8275f3b5c67e032850"},
+       ref: "90613b4bae875a3610c275b7056b61ffdd53210d"},
       {:pleroma_job_queue, "~> 0.2.0"},
       {:telemetry, "~> 0.3"},
       {:prometheus_ex, "~> 3.0"},
diff --git a/mix.lock b/mix.lock
index bb40ebd48..e13fdcbd4 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,6 +1,6 @@
 %{
   "accept": {:hex, :accept, "0.3.5", "b33b127abca7cc948bbe6caa4c263369abf1347cfa9d8e699c6d214660f10cd1", [:rebar3], [], "hexpm"},
-  "auto_linker": {:git, "https://git.pleroma.social/pleroma/auto_linker.git", "479dd343f4e563ff91215c8275f3b5c67e032850", [ref: "479dd343f4e563ff91215c8275f3b5c67e032850"]},
+  "auto_linker": {:git, "https://git.pleroma.social/pleroma/auto_linker.git", "90613b4bae875a3610c275b7056b61ffdd53210d", [ref: "90613b4bae875a3610c275b7056b61ffdd53210d"]},
   "base64url": {:hex, :base64url, "0.0.1", "36a90125f5948e3afd7be97662a1504b934dd5dac78451ca6e9abf85a10286be", [:rebar], [], "hexpm"},
   "bunt": {:hex, :bunt, "0.2.0", "951c6e801e8b1d2cbe58ebbd3e616a869061ddadcc4863d0a2182541acae9a38", [:mix], [], "hexpm"},
   "cachex": {:hex, :cachex, "3.0.2", "1351caa4e26e29f7d7ec1d29b53d6013f0447630bbf382b4fb5d5bad0209f203", [:mix], [{:eternal, "~> 1.2", [hex: :eternal, repo: "hexpm", optional: false]}, {:unsafe, "~> 1.0", [hex: :unsafe, repo: "hexpm", optional: false]}], "hexpm"},