From 633ac50f03586326ec8f70a2a2c34b9e167f4bf0 Mon Sep 17 00:00:00 2001
From: "Paolo G. Giarrusso" <p.giarrusso@gmail.com>
Date: Sun, 14 Aug 2016 13:05:19 +0200
Subject: [PATCH] Check executability in exec lookup (#2489)

Fix #2489. Nothing guarantees that files in the PATH are executable, and
Unix utilities handle this just fine.
---
 src/System/Process/Read.hs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/System/Process/Read.hs b/src/System/Process/Read.hs
index 56630b88a1..5c76d8f87e 100644
--- a/src/System/Process/Read.hs
+++ b/src/System/Process/Read.hs
@@ -345,7 +345,8 @@ findExecutable eo name = liftIO $ do
                         testFPs [] = loop dirs
                         testFPs (fp:fps) = do
                             exists <- D.doesFileExist fp
-                            if exists
+                            existsExec <- if exists then liftM D.executable $ D.getPermissions fp else return False
+                            if existsExec
                                 then do
                                     fp' <- D.makeAbsolute fp >>= parseAbsFile
                                     return $ return fp'