From 7c9b722f6abb6a0fff8a6bef496f61fa83f85897 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Thu, 2 Dec 2021 16:59:13 +0100
Subject: [PATCH] Make clear that equalFilePath does not expand ".."

Fixes #87
---
 System/FilePath/Internal.hs | 3 +++
 System/FilePath/Posix.hs    | 3 +++
 System/FilePath/Windows.hs  | 3 +++
 tests/TestGen.hs            | 2 ++
 4 files changed, 11 insertions(+)

diff --git a/System/FilePath/Internal.hs b/System/FilePath/Internal.hs
index 5a8f14f6..8a1e1391 100644
--- a/System/FilePath/Internal.hs
+++ b/System/FilePath/Internal.hs
@@ -768,9 +768,12 @@ joinPath = foldr combine ""
 --   first this has a much better chance of working.
 --   Note that this doesn't follow symlinks or DOSNAM~1s.
 --
+-- Similar to 'normalise', this does not expand @".."@, because of symlinks.
+--
 -- >          x == y ==> equalFilePath x y
 -- >          normalise x == normalise y ==> equalFilePath x y
 -- >          equalFilePath "foo" "foo/"
+-- >          not (equalFilePath "/a/../c" "/c")
 -- >          not (equalFilePath "foo" "/foo")
 -- > Posix:   not (equalFilePath "foo" "FOO")
 -- > Windows: equalFilePath "foo" "FOO"
diff --git a/System/FilePath/Posix.hs b/System/FilePath/Posix.hs
index 743d20d5..b7e61197 100644
--- a/System/FilePath/Posix.hs
+++ b/System/FilePath/Posix.hs
@@ -768,9 +768,12 @@ joinPath = foldr combine ""
 --   first this has a much better chance of working.
 --   Note that this doesn't follow symlinks or DOSNAM~1s.
 --
+-- Similar to 'normalise', this does not expand @".."@, because of symlinks.
+--
 -- >          x == y ==> equalFilePath x y
 -- >          normalise x == normalise y ==> equalFilePath x y
 -- >          equalFilePath "foo" "foo/"
+-- >          not (equalFilePath "/a/../c" "/c")
 -- >          not (equalFilePath "foo" "/foo")
 -- > Posix:   not (equalFilePath "foo" "FOO")
 -- > Windows: equalFilePath "foo" "FOO"
diff --git a/System/FilePath/Windows.hs b/System/FilePath/Windows.hs
index 6099975f..15877020 100644
--- a/System/FilePath/Windows.hs
+++ b/System/FilePath/Windows.hs
@@ -768,9 +768,12 @@ joinPath = foldr combine ""
 --   first this has a much better chance of working.
 --   Note that this doesn't follow symlinks or DOSNAM~1s.
 --
+-- Similar to 'normalise', this does not expand @".."@, because of symlinks.
+--
 -- >          x == y ==> equalFilePath x y
 -- >          normalise x == normalise y ==> equalFilePath x y
 -- >          equalFilePath "foo" "foo/"
+-- >          not (equalFilePath "/a/../c" "/c")
 -- >          not (equalFilePath "foo" "/foo")
 -- > Posix:   not (equalFilePath "foo" "FOO")
 -- > Windows: equalFilePath "foo" "FOO"
diff --git a/tests/TestGen.hs b/tests/TestGen.hs
index 37046dc9..6364537d 100755
--- a/tests/TestGen.hs
+++ b/tests/TestGen.hs
@@ -359,6 +359,8 @@ tests =
     ,("W.normalise x == W.normalise y ==> W.equalFilePath x y", property $ \(QFilePath x) (QFilePath y) -> W.normalise x == W.normalise y ==> W.equalFilePath x y)
     ,("P.equalFilePath \"foo\" \"foo/\"", property $ P.equalFilePath "foo" "foo/")
     ,("W.equalFilePath \"foo\" \"foo/\"", property $ W.equalFilePath "foo" "foo/")
+    ,("not (P.equalFilePath \"/a/../c\" \"/c\")", property $ not (P.equalFilePath "/a/../c" "/c"))
+    ,("not (W.equalFilePath \"/a/../c\" \"/c\")", property $ not (W.equalFilePath "/a/../c" "/c"))
     ,("not (P.equalFilePath \"foo\" \"/foo\")", property $ not (P.equalFilePath "foo" "/foo"))
     ,("not (W.equalFilePath \"foo\" \"/foo\")", property $ not (W.equalFilePath "foo" "/foo"))
     ,("not (P.equalFilePath \"foo\" \"FOO\")", property $ not (P.equalFilePath "foo" "FOO"))