and try to load the font family (guessed from the font name) before trying
the local substitution.
The local(...) command expects to have a real font name and not a predefined
substitution it's why we try the font family.
When a pdf as a FreeText without appearance, we use a fake font in order to render it
and that leads to create few new refs for the font.
But then when we're saving, we create some new refs which start at the same number
as the previous created ones.
Consequently, when saving we're using some wrong objects (like a font) to check if
we're able to render the newly added FreeText.
In order to fix this bug, we just remove the persistent refs (which are only used
when rendering/printing) during the saving.
Now that font-substitution has been implemented, we should be able to do much a better job at supporting non-embedded Wingdings fonts.
Given that this is a Windows-specific font, see https://en.wikipedia.org/wiki/Wingdings, this is however not guaranteed to work (well) on other platforms.
On my computer, it takes few tenths of a second to load a local font.
Since a font can be used several times in a document, the cache will
improve performances.
- Replace FoxitSans with LiberationSans: LiberationSans is already there (for XFA) and we can use
it as a good replacement of FoxitSans.
- For now we just try to substitue standard fonts, the strategy is the following:
* we try to find a font locally from a hardcoded list;
* if it fails then we use Liberation as fallback (only for Helvetica for the moment);
* else we just fallback on the system serif/sansserif/monospace font.
