From b78ca50cb3dda361f9c1e7a83af7e2e0fa0edbf2 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Tue, 16 May 2023 16:51:14 +0200
Subject: [PATCH] configure: generate a script to run the compiler
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in the CURL_RUN_IFELSE macro, with LD_LIBRARY_PATH set to the value of
the configure invoke, and not the value that might be used later,
intended for the execution of the output the compiler ouputs.

For example when the compiler uses the same library (like libz) that
configure checks for.

Reported-by: Jonas Bülow
Fixes #11114
Closes #11120
---
 configure.ac         | 13 +++++++++++++
 m4/curl-functions.m4 |  3 +++
 2 files changed, 16 insertions(+)

diff --git a/configure.ac b/configure.ac
index f832f710d2..ef82e944f4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -186,6 +186,17 @@ dnl
 INITIAL_LDFLAGS=$LDFLAGS
 INITIAL_LIBS=$LIBS
 
+dnl
+dnl Generates a shell script to run the compiler with LD_LIBRARY_PATH set to
+dnl the value used right now. This lets CURL_RUN_IFELSE set LD_LIBRARY_PATH to
+dnl something different but only have that affect the execution of the results
+dnl of the compile, not change the libraries for the compiler itself.
+dnl
+compilersh="run-compiler"
+echo "CC=$CC" > $compilersh
+echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH" >> $compilersh
+echo 'exec $CC $@' >> $compilersh
+
 dnl **********************************************************************
 dnl See which TLS backend(s) that are requested. Just do all the
 dnl TLS AC_ARG_WITH() invokes here and do the checks later
@@ -4396,6 +4407,8 @@ else
 fi
 AC_SUBST(LIBCURL_NO_SHARED)
 
+rm $compilersh
+
 dnl
 dnl For keeping supported features and protocols also in pkg-config file
 dnl since it is more cross-compile friendly than curl-config
diff --git a/m4/curl-functions.m4 b/m4/curl-functions.m4
index 4d4d13a400..bd2ebbd019 100644
--- a/m4/curl-functions.m4
+++ b/m4/curl-functions.m4
@@ -5866,11 +5866,14 @@ AC_DEFUN([CURL_RUN_IFELSE], [
       AC_RUN_IFELSE([AC_LANG_SOURCE([$1])], $2, $3, $4)
      ;;
      *)
+      oldcc=$CC
       old=$LD_LIBRARY_PATH
+      CC="sh ./run-compiler"
       LD_LIBRARY_PATH=$CURL_LIBRARY_PATH:$old
       export LD_LIBRARY_PATH
       AC_RUN_IFELSE([AC_LANG_SOURCE([$1])], $2, $3, $4)
       LD_LIBRARY_PATH=$old # restore
+      CC=$oldcc
      ;;
    esac
 ])
-- 
2.47.3