From 830f9fabd4a564bfbc3fbfc33a62b02010c0a7a5 Mon Sep 17 00:00:00 2001
From: Will Dietz <w@wdtz.org>
Date: Thu, 27 Sep 2018 17:40:16 -0500
Subject: [PATCH] patch-shebangs: use isScript to safely check for shebang
 start

Fixes commonly encountered errors about broken pipes or null-bytes in
command-substitution.
---
 pkgs/build-support/setup-hooks/patch-shebangs.sh | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/pkgs/build-support/setup-hooks/patch-shebangs.sh b/pkgs/build-support/setup-hooks/patch-shebangs.sh
index d5586fccae6..0ac81102658 100644
--- a/pkgs/build-support/setup-hooks/patch-shebangs.sh
+++ b/pkgs/build-support/setup-hooks/patch-shebangs.sh
@@ -19,9 +19,8 @@ patchShebangs() {
     local newInterpreterLine
 
     find "$dir" -type f -perm -0100 | while read f; do
-        if [ "$(head -1 "$f" | head -c+2)" != '#!' ]; then
-            # missing shebang => not a script
-            continue
+        if ! isScript "$f"; then
+          continue
         fi
 
         oldInterpreterLine=$(head -1 "$f" | tail -c+3)