From 3623504e5d7b4dd6dd250151685343109de1e889 Mon Sep 17 00:00:00 2001
From: "Haelwenn (lanodan) Monnier" <contact@hacktivis.me>
Date: Mon, 18 Jun 2018 12:45:15 +0200
Subject: [PATCH] [Pleroma.Formatter]: Add support for non-HTTP schemes in URIs
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The call to the regex in add_links is there just to be sure it’s a legal URI, it can be removed if you want to get more performance.

The URI Schemes list is sorted, but with http(s) at the start (in case it might make it faster for common links).

Closes: https://git.pleroma.social/pleroma/pleroma/issues/127
---
 lib/pleroma/formatter.ex | 32 ++++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/lib/pleroma/formatter.ex b/lib/pleroma/formatter.ex
index 0aaf21538..fe3da09ac 100644
--- a/lib/pleroma/formatter.ex
+++ b/lib/pleroma/formatter.ex
@@ -165,8 +165,29 @@ def get_custom_emoji() do
     @emoji
   end
 
-  @link_regex ~r/https?:\/\/[\w\.\/?=\-#\+%&@~'\(\):]+[\w\/]/u
+  @link_regex ~r/[0-9a-z+\-\.]+:[0-9a-z$-_.+!*'(),]+/ui
 
+  # IANA got a list https://www.iana.org/assignments/uri-schemes/ but
+  # Stuff like ipfs isn’t in it
+  # There is very niche stuff
+  @uri_schemes [
+    "https://",
+    "http://",
+    "dat://",
+    "dweb://",
+    "gopher://",
+    "ipfs://",
+    "ipns://",
+    "irc:",
+    "ircs:",
+    "magnet:",
+    "mailto:",
+    "mumble:",
+    "ssb://",
+    "xmpp:"
+  ]
+
+  # TODO: make it use something other than @link_regex
   def html_escape(text) do
     Regex.split(@link_regex, text, include_captures: true)
     |> Enum.map_every(2, fn chunk ->
@@ -176,11 +197,14 @@ def html_escape(text) do
     |> Enum.join("")
   end
 
-  @doc "changes http:... links to html links"
+  @doc "changes scheme:... urls to html links"
   def add_links({subs, text}) do
     links =
-      Regex.scan(@link_regex, text)
-      |> Enum.map(fn [url] -> {Ecto.UUID.generate(), url} end)
+      text
+      |> String.split([" ", "\t", "<br>"])
+      |> Enum.filter(fn word -> String.starts_with?(word, @uri_schemes) end)
+      |> Enum.filter(fn word -> Regex.match?(@link_regex, word) end)
+      |> Enum.map(fn url -> {Ecto.UUID.generate(), url} end)
       |> Enum.sort_by(fn {_, url} -> -String.length(url) end)
 
     uuid_text =