Make a copy of a `PangoFontDescription`, but don't duplicate allocated fields.
This is like [[email protected]], but only a shallow copy is made of the family name and other allocated fields. The result can only be used until this is modified or freed. This is meant to be used when the copy is only needed temporarily.
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a `PangoFontDescription`, may be null |
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the newly allocated `PangoFontDescription`, which should be freed with [[email protected]], or null if this was null. |