From 059dd6f681caf14ee9d288ec14b82132be29ae2c Mon Sep 17 00:00:00 2001
From: rinpatch <rinpatch@sdf.org>
Date: Tue, 18 Dec 2018 21:38:15 +0300
Subject: [PATCH 1/3] Ignore HTML characters in formatter.ex

---
 lib/pleroma/formatter.ex | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/pleroma/formatter.ex b/lib/pleroma/formatter.ex
index 46d0d926a..9401689cb 100644
--- a/lib/pleroma/formatter.ex
+++ b/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 @@ defmodule Pleroma.Formatter 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 =

From 8a67677d7791287905898bc388fbd8d9c81ec2b1 Mon Sep 17 00:00:00 2001
From: rinpatch <rinpatch@sdf.org>
Date: Tue, 18 Dec 2018 22:10:56 +0300
Subject: [PATCH 2/3] Add test

---
 test/formatter_test.exs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/test/formatter_test.exs b/test/formatter_test.exs
index bb318b7d5..cfa735795 100644
--- a/test/formatter_test.exs
+++ b/test/formatter_test.exs
@@ -22,6 +22,18 @@ defmodule Pleroma.FormatterTest 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\">#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

From 196d9c0fd089942deff62aeeea60bef1972cbe38 Mon Sep 17 00:00:00 2001
From: Rin Toshaka <rinpatch@sdf.org>
Date: Tue, 18 Dec 2018 20:30:04 +0100
Subject: [PATCH 3/3] Fix tests

---
 test/formatter_test.exs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/formatter_test.exs b/test/formatter_test.exs
index cfa735795..6cdfa4167 100644
--- a/test/formatter_test.exs
+++ b/test/formatter_test.exs
@@ -27,7 +27,7 @@ defmodule Pleroma.FormatterTest do
       text = "Fact #3: pleroma does what mastodon't"
 
       expected_text =
-        "Fact <a data-tag=\"3\" href=\"http://localhost:4001/tag/3\">#3</a>: pleroma does what mastodon't"
+        "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)