Overview:

When using wixl-heat to harvest a directory while not specifying any component group, the generated .wxs does not close the Wix tag.

Steps to Reproduce:

- Prepare a simple directory to harvest, say a directory foo and a file foo/bar.
- Run the following command to harvest the directory: `find foo | wixl-heat --prefix foo/`

Expected Result:

A well-formed XML document with balanced tags.

Actual Result:

A XML document with an open Wix tag and no matching close Wix tag.

Guess:

A suspicious line at tools/wixl/wixl-heat.vala [116-124]:

    116     if (cg != null) {
    117         stdout.printf ("  <Fragment>\n");
    118         stdout.printf ("    <ComponentGroup Id=\"%s\">\n".printf (cg));
    119         foreach (var id in cmpref)
    120             stdout.printf ("      <ComponentRef Id=\"%s\"/>\n".printf (id));
    121         stdout.printf ("    </ComponentGroup>\n");
    122         stdout.printf ("  </Fragment>\n");
    123         stdout.printf ("</Wix>\n");
    124     }

As the code fragment revealed, the close Wix tag is only generated if a component group is provided.