cache file name with spaces

[George Sicherman]

I am using autoconf 2.13 on a Cygwin system.  It is generating
configure files that contain this:

        if test -r "$cache_file"; then
          echo "loading cache $cache_file"
          . $cache_file
        else
          echo "creating cache $cache_file"
          > $cache_file
        fi

If the name of the cache file contains spaces, the ">" case works.
The "." command interprets the variable $cache_file as multiple
words, treating the first word as a file name and the rest as
arguments.

The fix is to write

        . "$cache_file"