Fix usage of --enable-XXX

config/pac.m4

@@ -1211,16 +1211,14 @@ AC_ARG_ENABLE(serial,
 AS_HELP_STRING([--enable-serial], 
 [Specify whether to enable a fake mpi library to run in serial mode. ]),
 [
-pac_cv_serial_mpi="yes";
+pac_cv_serial_mpi="$enableval";
 ]
-dnl ,
-dnl [pac_cv_serial_mpi="no";]
 )
 if test x"$pac_cv_serial_mpi" == x"yes" ; then
    AC_MSG_RESULT([yes.])
 else
- pac_cv_serial_mpi="no";
- AC_MSG_RESULT([no.])
+  pac_cv_serial_mpi="no";
+  AC_MSG_RESULT([no.])
 fi
 ]
 )
@@ -1317,10 +1315,8 @@ AC_ARG_ENABLE(long-integers,
 AS_HELP_STRING([--enable-long-integers], 
 [Specify usage of 64 bits integers. ]),
 [
-pac_cv_long_integers="yes";
+pac_cv_long_integers="$enableval";
 ]
-dnl ,
-dnl [pac_cv_long_integers="no";]
 )
 if test x"$pac_cv_long_integers" == x"yes" ; then
    AC_MSG_RESULT([yes.])

configure

@@ -5754,7 +5754,7 @@ printf %s "checking whether we want serial  mpi stubs... " >&6; }
 if test ${enable_serial+y}
 then :
   enableval=$enable_serial;
-pac_cv_serial_mpi="yes";
+pac_cv_serial_mpi="$enableval";
 
 
 fi
@@ -5763,8 +5763,8 @@ if test x"$pac_cv_serial_mpi" == x"yes" ; then
    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes." >&5
 printf "%s\n" "yes." >&6; }
 else
- pac_cv_serial_mpi="no";
- { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no." >&5
+  pac_cv_serial_mpi="no";
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no." >&5
 printf "%s\n" "no." >&6; }
 fi