Add cppunit detection using pkg-config

Obsolete cppunit-config was removed in cppunit 1.14.0

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>
(cherry picked from commit e0f1af443c)

acinclude.m4.in

@@ -6512,7 +6512,15 @@ if test "x$enable_cppunit" = "xyes"; then
               [  --enable-online-tests   Include online tests with CPPUNIT tests],,
               enable_online_tests=no)
   AC_MSG_RESULT($enable_online_tests)
+  cppunit_version_min=$1
 
+  if test "$PKG_CONFIG" != "no" && $PKG_CONFIG --exists cppunit; then
+     PKG_CHECK_MODULES(CPPUNIT, [cppunit >= $cppunit_version_min],,
+        [
+        AC_MSG_WARN(Minimum version of CPPUNIT couldn't be found. Tests will not be built)
+        no_cppunit=yes
+        ])
+  else
      if test x$cppunit_config_exec_prefix != x ; then
         cppunit_config_args="$cppunit_config_args --exec-prefix=$cppunit_config_exec_prefix"
         if test x${CPPUNIT_CONFIG+set} != xset ; then
@@ -6527,7 +6535,6 @@ if test "x$enable_cppunit" = "xyes"; then
      fi
 
      AC_PATH_PROG(CPPUNIT_CONFIG, cppunit-config, no)
-  cppunit_version_min=$1
 
      AC_MSG_CHECKING(for CPPUNIT - version >= $cppunit_version_min)
      no_cppunit=""
@@ -6570,6 +6577,8 @@ if test "x$enable_cppunit" = "xyes"; then
          no_cppunit=yes
        fi
      fi
+
+  fi
 else
   no_cppunit=user
 fi