[XeTeX] Ligatures and searching in PDFs

[Gareth Hughes]

Andy Lin wrote:
> In order to make the common f/ff ligatures searchable in PDFs, add the
> following lines and compile the map file with teckit_compile (should
> be in the bin folder):
> U+0066 U+0066	<>	U+FB00	; ff -> ff ligature
> U+0066 U+0069	<>	U+FB01	; fi -> fi ligature
> U+0066 U+006C	<>	U+FB02	; fl -> fl ligature
> U+0066 U+0066 U+0069	<>	U+FB03	; ffi -> ffi ligature
> U+0066 U+0066 U+006C	<>	U+FB04	; ffl -> ffl ligature
> 
> I've attached such a map file and the resulting tec file for those who
> aren't interested in the nitty-gritty. Simply drop these into the
> fonts\misc\xetex\fontmapping folder and run texhash/mktexlsr.

I had noticed that the ligatures 'ch' and 'Th' are not searchable in
Linux Libertine. I added the following mappings:
U+0063 U+0068	<>	U+E03B	; ch -> ch ligature
U+0054 U+0068	<>	U+E049	; Th -> Th ligature
But these do not make it possible to search or copy/paste as uncompiled.
The .tec file is compiled correctly and XeTeX finds it. Any thoughts?

Gareth.