From e1f8c4b396354f8bf29c3b9f04e9b3f980c70d31 Mon Sep 17 00:00:00 2001
From: Even Brenden <evenbrenden@gmail.com>
Date: Thu, 27 Jan 2022 23:56:07 +0100
Subject: [PATCH] Handle consecutive ".."s in makeCanonical
As an example, prior to this commit, "../../file" would evaluate to
"file", when it should be unchanged.
---
src/Text/Pandoc/Class/PandocMonad.hs | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/src/Text/Pandoc/Class/PandocMonad.hs b/src/Text/Pandoc/Class/PandocMonad.hs
index 144a13ba4..05cc156d0 100644
--- a/src/Text/Pandoc/Class/PandocMonad.hs
+++ b/src/Text/Pandoc/Class/PandocMonad.hs
@@ -637,9 +637,10 @@ checkExistence fn = do
makeCanonical :: FilePath -> FilePath
makeCanonical = Posix.joinPath . transformPathParts . splitDirectories
where transformPathParts = reverse . foldl' go []
- go as "." = as
- go (_:as) ".." = as
- go as x = x : as
+ go as "." = as
+ go ("..":as) ".." = ["..", ".."] <> as
+ go (_:as) ".." = as
+ go as x = x : as
-- | Tries to run an action on a file: for each directory given, a
-- filepath is created from the given filename, and the action is run on