Re: [help-texinfo] No index in PDF manual

[Gavin Smith]

> I've had another idea: add a conditional like \txiindexbackslash to use 
> backslash as the escape character, and refer to this in the note where 
> the index should be.  Then the user would at least have the choice of 
> trying to typeset the index with their version of texi2dvi
> (using 'texi2dvi -t @set\ txiindexbackslash'), even if 
> upgrading texi2dvi or running texindex by hand would be better options.

I've done this in commit cc81973.  I've tried to avoid either raw 
backslashes or at signs appearing the index file, so the only difference 
is that the escape character is changed.  Backslashes are used if the
user gives '@set txiindexescapeisbackslash'.  User-defined macros involving 
backslashes, at signs or braces in indices are likely not to work.