From a1154d6348511153fe41da3656c7ec4a35be9a83 Mon Sep 17 00:00:00 2001
From: DavHau <hsngrmpf+github@gmail.com>
Date: Mon, 7 Jul 2025 14:57:21 +0700
Subject: [PATCH] patch-shebangs: fix binary data corrupt after patching

This removes the recently introduced shell based implementation of `sponge` which wasn't capable of managing binary input.

Now, a tmpFile under $TMPDIR is created manually and later deleted

see: https://github.com/NixOS/nixpkgs/pull/414448#issuecomment-3041238623
---
 .../setup-hooks/patch-shebangs.sh             | 48 ++++++++-----------
 pkgs/test/stdenv/patch-shebangs.nix           | 39 +++++++++++++++
 2 files changed, 59 insertions(+), 28 deletions(-)

diff --git a/pkgs/build-support/setup-hooks/patch-shebangs.sh b/pkgs/build-support/setup-hooks/patch-shebangs.sh
index 7fb6dc86c87a0..5bd1f5078ad00 100644
--- a/pkgs/build-support/setup-hooks/patch-shebangs.sh
+++ b/pkgs/build-support/setup-hooks/patch-shebangs.sh
@@ -68,31 +68,6 @@ patchShebangs() {
         return 0
     fi
 
-    # like sponge from moreutils but in pure bash
-    _sponge() {
-        local content
-        local target
-        local restoreReadOnly
-        content=""
-        target="$1"
-
-        # Make file writable if it is read-only
-        if [[ ! -w "$target" ]]; then
-            chmod +w "$target"
-            restoreReadOnly=true
-        fi
-
-        while IFS= read -r line || [[ -n "$line" ]]; do
-            content+="$line"$'\n'
-        done
-        printf '%s' "$content" > "$target"
-
-        # Restore read-only if it was read-only before
-        if [[ -n "${restoreReadOnly:-}" ]]; then
-            chmod -w "$target"
-        fi
-    }
-
     local f
     while IFS= read -r -d $'\0' f; do
         isScript "$f" || continue
@@ -151,14 +126,31 @@ patchShebangs() {
 
                 # Preserve times, see: https://github.com/NixOS/nixpkgs/pull/33281
                 timestamp=$(stat --printf "%y" "$f")
-                sed -e "1 s|.*|#\!$escapedInterpreterLine|" "$f" | _sponge "$f"
+
+                # Manually create temporary file instead of using sed -i
+                # (sed -i on $out/x creates tmpfile /nix/store/x which fails on macos + sandbox)
+                tmpFile=$(mktemp -t patchShebangs.XXXXXXXXXX)
+                sed -e "1 s|.*|#\!$escapedInterpreterLine|" "$f" > "$tmpFile"
+
+                # Make original file writable if it is read-only
+                local restoreReadOnly
+                if [[ ! -w "$f" ]]; then
+                    chmod +w "$f"
+                    restoreReadOnly=true
+                fi
+
+                # Replace the original file's content with the patched content
+                # (preserving permissions)
+                cat "$tmpFile" > "$f"
+                rm "$tmpFile"
+                if [[ -n "${restoreReadOnly:-}" ]]; then
+                    chmod -w "$f"
+                fi
 
                 touch --date "$timestamp" "$f"
             fi
         fi
     done < <(find "$@" -type f -perm -0100 -print0)
-
-    unset -f _sponge
 }
 
 patchShebangsAuto () {
diff --git a/pkgs/test/stdenv/patch-shebangs.nix b/pkgs/test/stdenv/patch-shebangs.nix
index 392f9630a1d1a..653058dca130b 100644
--- a/pkgs/test/stdenv/patch-shebangs.nix
+++ b/pkgs/test/stdenv/patch-shebangs.nix
@@ -204,6 +204,44 @@ let
       // {
         meta = { };
       };
+
+    preserves-binary-data =
+      (derivation {
+        name = "preserves-binary-data";
+        system = stdenv.buildPlatform.system;
+        builder = "${stdenv.__bootPackages.stdenv.__bootPackages.bashNonInteractive}/bin/bash";
+        initialPath = [
+          stdenv.__bootPackages.stdenv.__bootPackages.coreutils
+        ];
+        strictDeps = false;
+        args = [
+          "-c"
+          ''
+            set -euo pipefail
+            . ${../../stdenv/generic/setup.sh}
+            . ${../../build-support/setup-hooks/patch-shebangs.sh}
+            mkdir -p $out/bin
+            # Create a script with binary data after the shebang
+            echo "#!/bin/bash" > $out/bin/test
+            echo "echo 'script start'" >> $out/bin/test
+            # Add some binary data (null bytes and other non-printable chars)
+            printf '\x00\x01\x02\xff\xfe' >> $out/bin/test
+            echo >> $out/bin/test
+            echo "echo 'script end'" >> $out/bin/test
+            chmod +x $out/bin/test
+            patchShebangs $out/bin/test
+            # Verify binary data is still present by checking file size and content
+            if ! printf '\x00\x01\x02\xff\xfe' | cmp -s - <(sed -n '3p' $out/bin/test | tr -d '\n'); then
+              echo "Binary data corrupted during patching"
+              exit 1
+            fi
+          ''
+        ];
+        assertion = "grep '^#!${stdenv.shell}' $out/bin/test > /dev/null";
+      })
+      // {
+        meta = { };
+      };
   };
 in
 stdenv.mkDerivation {
@@ -219,6 +257,7 @@ stdenv.mkDerivation {
       read-only-script
       preserves-read-only
       preserves-timestamp
+      preserves-binary-data
       ;
   };
   buildCommand = ''