From df5fa309c2c8188da64b123488351d11002587bd Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Tue, 27 Feb 2024 12:12:59 +0100
Subject: [PATCH] sort: make the startup time optimization effective on glibc <
 2.34

* configure.ac: Test where to find the dlopen function. Set LIB_DL.
Use it in the DLOPEN_LIBCRYPTO test.
* src/local.mk (src_sort_LDADD): Add $(LIB_DL).
---
 configure.ac | 11 ++++++++++-
 src/local.mk |  2 +-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index fe8408a06..248e30ca2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -351,6 +351,15 @@ if test $utils_cv_localtime_cache = yes; then
   AC_DEFINE([LOCALTIME_CACHE], [1], [FIXME])
 fi
 
+# Find the library for dynamic loading of shared libraries.
+AC_SEARCH_LIBS([dlopen], [dl])
+AS_CASE([$ac_cv_search_dlopen],
+  [no | 'none required'],
+    [LIB_DL=],
+  [*],
+    [LIB_DL="$ac_cv_search_dlopen"])
+AC_SUBST([LIB_DL])
+
 # Should 'sort' link libcrypto dynamically?
 AS_CASE([$LIB_CRYPTO],
   [-lcrypto],
@@ -360,7 +369,7 @@ AS_CASE([$LIB_CRYPTO],
        [utils_cv_dlopen_libcrypto],
        [utils_cv_dlopen_libcrypto=no
         saved_LIBS=$LIBS
-        LIBS="$LIBS $LIB_CRYPTO"
+        LIBS="$LIBS $LIB_DL $LIB_CRYPTO"
         AC_LINK_IFELSE(
           [AC_LANG_PROGRAM(
              [[#include <dlfcn.h>
diff --git a/src/local.mk b/src/local.mk
index 7bc5ba5bc..96ee941ca 100644
--- a/src/local.mk
+++ b/src/local.mk
@@ -304,7 +304,7 @@ src_printf_LDADD += $(LIBICONV)
 
 # for libcrypto hash routines
 src_md5sum_LDADD += $(LIB_CRYPTO)
-src_sort_LDADD += $(LIB_CRYPTO)
+src_sort_LDADD += $(LIB_DL) $(LIB_CRYPTO)
 src_sha1sum_LDADD += $(LIB_CRYPTO)
 src_sha224sum_LDADD += $(LIB_CRYPTO)
 src_sha256sum_LDADD += $(LIB_CRYPTO)
-- 
2.11.4.GIT