From 5454aad32474472a8f977c941e6f7d70e925bcc5 Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Tue, 16 Jul 2019 09:27:51 -0700
Subject: [PATCH] Make filterIpynbOutput strip ANSI escapes from code in
output...
for non-ipynb formats, when the default "best" option is used with
--ipynb-output. The escape sequences cause problems in many formats,
including LaTeX. Closes #5633.
---
src/Text/Pandoc/Shared.hs | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index 2fb9cbac3..a17c1fff2 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -688,7 +688,8 @@ splitSentences xs =
-- | Process ipynb output cells. If mode is Nothing,
-- remove all output. If mode is Just format, select
--- best output for the format.
+-- best output for the format. If format is not ipynb,
+-- strip out ANSI escape sequences from CodeBlocks (see #5633).
filterIpynbOutput :: Maybe Format -> Pandoc -> Pandoc
filterIpynbOutput mode = walk go
where go (Div (ident, ("output":os), kvs) bs) =
@@ -699,6 +700,7 @@ filterIpynbOutput mode = walk go
| fmt == Format "ipynb"
-> Div (ident, ("output":os), kvs) bs
| otherwise -> Div (ident, ("output":os), kvs) $
+ walk removeANSI $
take 1 $ sortBy (comparing rank) bs
where
rank (RawBlock (Format "html") _)
@@ -714,6 +716,13 @@ filterIpynbOutput mode = walk go
| otherwise = 3
rank (Para [Image{}]) = 1
rank _ = 2
+ removeANSI (CodeBlock attr code) =
+ CodeBlock attr (removeANSIEscapes code)
+ removeANSI x = x
+ removeANSIEscapes [] = []
+ removeANSIEscapes ('\x1b':'[':cs) =
+ removeANSIEscapes (drop 1 $ dropWhile (/='m') cs)
+ removeANSIEscapes (c:cs) = c : removeANSIEscapes cs
go x = x
--