Downcase tags coming in through the TwAPI.

lib/pleroma/formatter.ex

@@ -9,7 +9,7 @@ def linkify(text) do
   @tag_regex ~r/\#\w+/u
   def parse_tags(text) do
     Regex.scan(@tag_regex, text)
-    |> Enum.map(fn (["#" <> tag = full_tag]) -> {full_tag, tag} end)
+    |> Enum.map(fn (["#" <> tag = full_tag]) -> {full_tag, String.downcase(tag)} end)
   end
 
   def parse_mentions(text) do

test/formatter_test.exs

@@ -16,9 +16,9 @@ test "turning urls into links" do
 
   describe ".parse_tags" do
     test "parses tags in the text" do
-      text = "Here's a #test. Maybe these are #working or not. What about #漢字? And #は｡"
+      text = "Here's a #Test. Maybe these are #working or not. What about #漢字? And #は｡"
       expected = [
-        {"#test", "test"},
+        {"#Test", "test"},
         {"#working", "working"},
         {"#漢字", "漢字"},
         {"#は", "は"}