Use autoconf's result of AC_CHECK_SIZEOF(long) in CURL_CONFIGURE_LONG

acinclude.m4

@@ -3646,33 +3646,11 @@ dnl The size of long is a build time characteristic and as such
 dnl must be recorded in curlbuild.h
 
 AC_DEFUN([CURL_CONFIGURE_LONG], [
-  AC_REQUIRE([CURL_INCLUDES_INTTYPES])dnl
-  if test ! -z "$ac_cv_sizeof_long"; then
-    AC_MSG_WARN([Use CURL-CONFIGURE-LONG to check the size of long first])
-  fi
-  AC_MSG_CHECKING([size of long])
-  curl_sizeof_long="unknown"
-  for tmp_size in '16' '8' '4' '2' '1' ; do
-    if test "$curl_sizeof_long" = "unknown"; then
-      AC_COMPILE_IFELSE([
-        AC_LANG_PROGRAM([[
-          $curl_includes_inttypes
-          typedef char dummy_arr[sizeof(long) == $tmp_size ? 1 : -1];
-        ]],[[
-          dummy_arr[1] = (long)1;
-        ]])
-      ],[
-        curl_sizeof_long="$tmp_size"
-      ])
-    fi
-  done
-  if test "$curl_sizeof_long" = "unknown"; then
-    AC_MSG_ERROR([cannot find out size of long])
-  else
-    AC_MSG_RESULT([$curl_sizeof_long])
-    CURL_DEFINE_UNQUOTED([CURL_SIZEOF_LONG], [$curl_sizeof_long])
-    ac_cv_sizeof_long="$curl_sizeof_long"
+  if test -z "$ac_cv_sizeof_long" ||
+    test "$ac_cv_sizeof_long" -eq "0"; then
+    AC_MSG_ERROR([cannot find out size of long.])
   fi
+  CURL_DEFINE_UNQUOTED([CURL_SIZEOF_LONG], [$ac_cv_sizeof_long])
 ])
 
 
@@ -3761,9 +3739,13 @@ AC_DEFUN([CURL_CONFIGURE_CURL_OFF_T], [
     AC_MSG_ERROR([SED not set. Cannot continue without SED being set.])
   fi
   #
-  CURL_CONFIGURE_LONG
+  AC_CHECK_SIZEOF(long)
   AC_CHECK_SIZEOF(void*)
   #
+  if test -z "$ac_cv_sizeof_long" ||
+    test "$ac_cv_sizeof_long" -eq "0"; then
+    AC_MSG_ERROR([cannot find out size of long.])
+  fi
   if test -z "$ac_cv_sizeof_voidp" ||
      test "$ac_cv_sizeof_voidp" -eq "0"; then
     AC_MSG_ERROR([cannot find out size of void*.])

configure.ac

@@ -1996,6 +1996,7 @@ CURL_VERIFY_RUNTIMELIBS
 
 AC_CHECK_SIZEOF(size_t)
 AC_CHECK_SIZEOF(long)
+CURL_CONFIGURE_LONG
 AC_CHECK_SIZEOF(time_t)
 AC_CHECK_SIZEOF(off_t)