Allow the following:
```
<msl>
<read>
<composite x="0" y="0" compose="Darken">
<image id="mask">
<extent width="100" height="100" gravity="Center" backgroundColor="#fff" />
</image>
</composite>
</read>
</msl>
```
Comments: Resolved with changeset 32438: Allowed operations on image argument in MagickScript.
```
<msl>
<read>
<composite x="0" y="0" compose="Darken">
<image id="mask">
<extent width="100" height="100" gravity="Center" backgroundColor="#fff" />
</image>
</composite>
</read>
</msl>
```
Comments: Resolved with changeset 32438: Allowed operations on image argument in MagickScript.