FYI: HEAD: avoid setting $libobjs to a single space

[Ralf Wildenhues]

This is the first of a small set of patches which I split the fix for
the failures connected to test 49 (Run tests with low max_cmd_len) into.

It takes care that we never set $libobjs to a single space.  In each of
the fixed places, either we have two input variables which may both be
empty, or we have a pipe into $NL2SP of some possibly empty input, which
will end up with a single space as well.[1]

The patch allows to check for empty $libobjs more nicely.  Note that
this is already done, so far bogusly, for some optimization.

Applied to HEAD as hopefully obvious enough.  ;-)

Cheers,
Ralf

[1] No, a pipe into
   ... | $NL2SP | $SED 's, $,,'
won't do as well.  One reason for the pipe in the first place is to
avoid sed's line length limitations.

2007-02-23  Ralf Wildenhues  <address@hidden>

        * libltdl/config/ltmain.m4sh (func_mode_link): Avoid setting
        `$libobjs' to a single space; set it to empty in that case.

Index: libltdl/config/ltmain.m4sh
===================================================================
RCS file: /cvsroot/libtool/libtool/libltdl/config/ltmain.m4sh,v
retrieving revision 1.65
diff -u -r1.65 ltmain.m4sh
--- libltdl/config/ltmain.m4sh  23 Feb 2007 19:45:42 -0000      1.65
+++ libltdl/config/ltmain.m4sh  23 Feb 2007 20:39:57 -0000
@@ -4533,6 +4533,7 @@
 
       func_generate_dlsyms "$libname" "$libname" "yes"
       libobjs="$libobjs $symfileobj"
+      test "X$libobjs" = "X " && libobjs=
 
       if test "$mode" != relink; then
        # Remove our outputs, but don't remove object files since they
@@ -5088,6 +5089,7 @@
 
        # Use standard objects if they are pic
        test -z "$pic_flag" && libobjs=`$ECHO "X$libobjs" | $SP2NL | $Xsed -e 
"$lo2o" | $NL2SP`
+       test "X$libobjs" = "X " && libobjs=
 
        delfiles=
        if test -n "$export_symbols" && test -n "$include_expsyms"; then
@@ -5183,12 +5185,14 @@
          if test -n "$whole_archive_flag_spec"; then
            save_libobjs=$libobjs
            eval libobjs=\"\$libobjs $whole_archive_flag_spec\"
+           test "X$libobjs" = "X " && libobjs=
          else
            gentop="$output_objdir/${outputname}x"
            generated="$generated $gentop"
 
            func_extract_archives $gentop $convenience
            libobjs="$libobjs $func_extract_archives_result"
+           test "X$libobjs" = "X " && libobjs=
          fi
        fi
 
@@ -5357,6 +5361,7 @@
 
          if test -n "$convenience" && test -n "$whole_archive_flag_spec"; then
            eval libobjs=\"\$libobjs $whole_archive_flag_spec\"
+           test "X$libobjs" = "X " && libobjs=
          fi
          # Expand the library linking commands again to reset the
          # value of $libobjs for piecewise linking.
@@ -5389,6 +5394,7 @@
 
          func_extract_archives $gentop $dlprefiles
          libobjs="$libobjs $func_extract_archives_result"
+         test "X$libobjs" = "X " && libobjs=
        fi
 
        save_ifs="$IFS"; IFS='~'