Re: ugly tinfo ABI problem

[Thomas Dickey]

On Mon, 17 Jan 2005, Stanislav Ievlev wrote:

> In current snapshot libtinfo and libtinfow are binary incompatible,
> because structures "screen" and "SLK" use NCURSES_CH_T type.
>
> In our distribution (ALT Linux) we are using scheme with separate tinfo as a
> replacement of libtermcap (shared library ncurses + shared library tinfo).
> So we have an applications that use libtinfo library only.
>
> So in unicode enviroment we will have two version of tinfo library. Some
> of applications will be linked with libtinfow, and others with libtinfo.
>
> We supports both unicode and non-unicode enviroments, so we will have a big
> problems.
>
> Why "terminal information" library depends on build type: widechar or
> nonwidechar?
> "libtinfo" must be a replacement of "libtermcap",but it will not be such
> replacement until ABI problem above exist.

The particular problem I was working on was to add bits to the color 
information (something that I overlooked in the initial changes for 
libncursesw but should have been part of it).  So far I've merged in about 
1/3 of the changes to do this.

The pieces you see are the ones that increase the storage.  There's
also a piece to add on the end of WINDOW, to ensure that offsets remain
the same - so I intended handling that as a special case.  I can do the
same for SCREEN (hadn't thought it necessary).  I'm not sure about the
impact on SLK until I can review the code.  But it sounds as if I should
make special cases for all three.

> Could you fix it?

probably - I hadn't thought about that part of the problem when I started
this.  Generally I'd like to keep the lower-level compatible - not struct
sizes, but offsets.  Keeping the color extension in a separate location
will make it more complicated though.

--
Thomas E. Dickey
http://invisible-island.net
ftp://invisible-island.net