FYI: loop in libtool m4 macros

[Ralf Wildenhues]

FYI: I have applied this patch to HEAD and branch-2-0 after some
reformatting.

Regards,
Ralf

2005-06-11  Ralf Menzel  <address@hidden>,
            Ralf Wildenhues  <address@hidden>

        * m4/ltoptions.m4 (_LT_SET_OPTIONS): Loop options only if
        nonempty.
        * m4/ltsugar.m4 (lt_combine): Don't test against empty quotes,
        test against empty arg.  Fixes infinite m4 loop with CVS Autoconf.

Index: m4/ltoptions.m4
===================================================================
RCS file: /cvsroot/libtool/libtool/m4/ltoptions.m4,v
retrieving revision 1.10
diff -u -r1.10 ltoptions.m4
--- m4/ltoptions.m4     8 Jan 2005 21:17:57 -0000       1.10
+++ m4/ltoptions.m4     11 Jun 2005 11:10:54 -0000
@@ -51,12 +51,14 @@
 # dispatch to that macro; otherwise complain about the unknown option
 # and exit.
 m4_define([_LT_SET_OPTIONS],
-[AC_FOREACH([_LT_Option], [$1],
-    [_LT_SET_OPTION(_LT_Option)
-    m4_ifdef(_LT_MANGLE_DEFUN(_LT_Option),
-               _LT_MANGLE_DEFUN(_LT_Option),
-       [m4_fatal([Unknown option `]_LT_Option[' to LT][_INIT_LIBTOOL])])
-    ])dnl
+[m4_if([$1], [], [],
+       [AC_FOREACH([_LT_Option], [$1],
+                  [_LT_SET_OPTION(_LT_Option)
+                       m4_ifdef(_LT_MANGLE_DEFUN(_LT_Option),
+                                _LT_MANGLE_DEFUN(_LT_Option),
+               [m4_fatal([Unknown option `]_LT_Option[' to 
LT][_INIT_LIBTOOL])])
+                  ])dnl
+       ])
 dnl
 dnl Simply set some default values (i.e off) if boolean options were not
 dnl specified:
Index: m4/ltsugar.m4
===================================================================
RCS file: /cvsroot/libtool/libtool/m4/ltsugar.m4,v
retrieving revision 1.3
diff -u -r1.3 ltsugar.m4
--- m4/ltsugar.m4       8 Jan 2005 21:17:57 -0000       1.3
+++ m4/ltsugar.m4       11 Jun 2005 11:10:54 -0000
@@ -38,7 +38,7 @@
 # PREFIX-LIST with SUFFIX1 through SUFFIXn.  Each element of the list
 # has the form PREFIXmINFIXSUFFIXn.
 m4_define([lt_combine],
-[m4_if([$2], [[]], [],
+[m4_if([$2], [], [],
        [lt_join(m4_quote(m4_default([$1], [, ])),
                _$0([$1], m4_car($2)[$3], m4_shiftn(3, $@)),
                $0([$1], m4_cdr($2), m4_shiftn(2, $@)))])])