[openwrt/openwrt] scripts: bundle-libraries.sh: retain preloaded libraries

[LEDE Commits]

jow pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/10dbdeccfadb56557d267e3dc8f22d6bafbb422f

commit 10dbdeccfadb56557d267e3dc8f22d6bafbb422f
Author: Jo-Philipp Wich <jo at mein.io>
AuthorDate: Thu Sep 10 13:55:48 2020 +0200

    scripts: bundle-libraries.sh: retain preloaded libraries
    
    Since the introduction of fakeroot support, wrapped SDK executables might
    be invoked from a shell that has libfakeroot.so preloaded.
    
    Since we're using preloading as well in order to mangle argv[0] when
    invoking the shipped ELF interpreter directly, we must take care of
    preloading the already preloaded libraries as well, to avoid invoked
    programs losing their fakeroot capabilities.
    
    Extend the bundle-libraries.sh script to take any existing $LD_PRELOAD
    into account when invoking the target ELF executable with a preloaded
    runas.so library.
    
    Signed-off-by: Jo-Philipp Wich <jo at mein.io>
---
 scripts/bundle-libraries.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/bundle-libraries.sh b/scripts/bundle-libraries.sh
index d3c7206a4d..9efcbbd0b2 100755
--- a/scripts/bundle-libraries.sh
+++ b/scripts/bundle-libraries.sh
@@ -186,7 +186,7 @@ for BIN in "$@"; do
 			#!/usr/bin/env bash
 			dir="\$(dirname "\$0")"
 			export RUNAS_ARG0="\$0"
-			export LD_PRELOAD="\$dir/${REL:+$REL/}runas.so"
+			export LD_PRELOAD="\${LD_PRELOAD:+\$LD_PRELOAD:}\$dir/${REL:+$REL/}runas.so"
 			exec "\$dir/${REL:+$REL/}$LDSO" --library-path "\$dir/${REL:+$REL/}" "\$dir/.${BIN##*/}.bin" "\$@"
 		EOF