From 2d6a43f4853f32149d5e751dc7af7cbc6c2e7122 Mon Sep 17 00:00:00 2001
From: Adrian Cochrane <adrian@openwork.nz>
Date: Thu, 16 Jan 2020 17:48:25 +1300
Subject: [PATCH] Fix CSS charset detection.

Previously I didn't handle cases where the charset was unspecified,
or where it wasn't valid text in the charsets I trialled.
---
 src/Main.hs | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/Main.hs b/src/Main.hs
index 23eeaee..f528f43 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -84,9 +84,15 @@ retreiveStyles uri html manager base = do
     lowerVars _ = CSSCond.B False
     lowerToks _ = CSSCond.B False
 
-applyCSScharset (charset:charsets) bytes | cssCharset (CSSTok.tokenize text) == charset = text
+applyCSScharset (charset:charsets) bytes | cssCharset (CSSTok.tokenize text') == charset = text
         | otherwise = applyCSScharset charsets bytes
-    where text = convertCharset charset bytes
+    where
+        text = convertCharset charset bytes
+        -- I don't know how better to handle these errors in the APIs I'm using...
+        text' = unsafePerformIO $ catch (evaluate text) handleDecodeError
+        handleDecodeError :: UnicodeException -> IO Text -- Type signature REQUIRED
+        handleDecodeError _ = return ""
+applyCSScharset _ bytes = convertCharset "utf-8" bytes
 cssCharset toks | (CSSTok.AtKeyword "charset":toks') <- skipCSSspace toks,
         (CSSTok.String charset:_) <- skipCSSspace toks' = charset
     | otherwise = ""
-- 
2.30.2