Merge branch 'fix/formatter-ignore-html-chars' into 'develop'

[#441] Fix characters converted to HTML being picked up by hashtag parser

See merge request pleroma/pleroma!575

lib/pleroma/formatter.ex

@@ -4,12 +4,12 @@ defmodule Pleroma.Formatter do
   alias Pleroma.HTML
   alias Pleroma.Emoji
 
-  @tag_regex ~r/\#\w+/u
+  @tag_regex ~r/((?<=[^&])|\A)(\#)(\w+)/u
   @markdown_characters_regex ~r/(`|\*|_|{|}|[|]|\(|\)|#|\+|-|\.|!)/
 
   def parse_tags(text, data \\ %{}) do
     Regex.scan(@tag_regex, text)
-    |> Enum.map(fn ["#" <> tag = full_tag] -> {full_tag, String.downcase(tag)} end)
+    |> Enum.map(fn ["#" <> tag = full_tag | _] -> {full_tag, String.downcase(tag)} end)
     |> (fn map ->
           if data["sensitive"] in [true, "True", "true", "1"],
             do: [{"#nsfw", "nsfw"}] ++ map,
@@ -155,7 +155,7 @@ def add_hashtag_links({subs, text}, tags) do
     uuid_text =
       tags
       |> Enum.reduce(text, fn {match, _short, uuid}, text ->
-        String.replace(text, match, uuid)
+        String.replace(text, ~r/((?<=[^&])|(\A))#{match}/, uuid)
       end)
 
     subs =

test/formatter_test.exs

@@ -22,6 +22,18 @@ test "turns hashtags into links" do
       assert expected_text ==
                Formatter.add_hashtag_links({[], text}, tags) |> Formatter.finalize()
     end
+
+    test "does not turn html characters to tags" do
+      text = "Fact #3: pleroma does what mastodon't"
+
+      expected_text =
+        "Fact <a data-tag='3' href='http://localhost:4001/tag/3' rel='tag'>#3</a>: pleroma does what mastodon't"
+
+      tags = Formatter.parse_tags(text)
+
+      assert expected_text ==
+               Formatter.add_hashtag_links({[], text}, tags) |> Formatter.finalize()
+    end
   end
 
   describe ".add_links" do