From 3c4e4bb7264afeab0704df287343d4c77ca8f8a1 Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Fri, 5 Aug 2022 16:24:51 +0200
Subject: [PATCH] Fix build with older pkg-config versions

The PKG_CHECK_VAR macro was introduced in pkg-config 0.28. Guard the
invocation with m4_ifdef.

Fixes #374.
---
 configure.ac | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index b4564d718..1a684642a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1226,7 +1226,8 @@ else
         [have_libicu=no])
 
     if test "x$have_libicu" = "xyes"; then
-        PKG_CHECK_VAR([ICU_DEFS], [icu-i18n], [DEFS])
+        m4_ifdef([PKG_CHECK_VAR],
+            [PKG_CHECK_VAR([ICU_DEFS], [icu-i18n], [DEFS])])
         if test "x$ICU_DEFS" != "x"; then
             CPPFLAGS="$CPPFLAGS $ICU_DEFS"
         fi