[pdftex] Problems with pdftex.map

[The Thanh Han]

> RK> The intention is that a font should appear only once in a document.
> RK> This is reasonable.
> 
> the outlines of the font. In fact, pdftex makes a very nice job on this,
> it even deals with included PDFs that use a font which is not included.
> It will define a new font with its own encoding for each included PDF,
> which is safe because you may include PDFs with MacRoman encoding
> together withs PDFs with the same font, but 8r encoded or anything else.
> It keeps track of the characters used in each included PDF, encode them
> in the particular fontlet, and subset once the font with all used chars.
> 
> RK> If pdfTeX substitutes a font, it lookes into pdftex.map and obviously
> RK> uses the first entry which matches "URWPalladioL-Roma".
> 
> I wasn't aware of this. I've been using this feature for years now (I'm
> the one who asked for it, I believe). I must confess that I use my own
>  .map files, and I'd never had the idea to define variants before base
> fonts. Yes, this is a shortcoming.
> 
> RK> Ideally pdfTeX should look for "URWPalladioL-Roma" in the map-file and
> RK> associate this with "uplr8a.pfb".  No more, no less.
> 
> yes.
> 
> RK> Things like ".82 ExtendFont" should be ignored when reading the map
> RK> file.
> 
> I suppose you mean "lines containing things like..."; and Slantfont too,
> of course, which is much more frequent.
> 
> RK> Even if pdfTeX finds the line
> RK> pplr8r URWPalladioL-Roma "TeXBase1Encoding ReEncodeFont" <8r.enc <uplr8a.pfb
> 
> RK> is it correct to apply "TeXBase1Encoding ReEncodeFont"?

Thierry gave an excellent explaination. Yes this is a bug of pdftex that it
didn't ignore map entries with SlantFont and ExtentFont. It will be fixed.

Another bug related to this topic is that if pdftex finds a map entry for a
font in an included pdf (using FontName), then the font file will not be
copied but pdftex supposes that it will include the font file itself. Which
causes trouble when the font file is given in the map file but not
available on disk. I will change pdftex to check in such cases whether the
font file is available on disk first; if not the the font will be copied
from the included pdf.

This won't solve the problem when you include a lot of PDF using the same
font, but the font itself is not available on disk; pdftex can't (and
probably it won't) merge multiple font subsets.

Thanh