Debian bug report logs - #1677
tgetent() returns unexpected error return codes

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From mdd.comm.mot.com!mitchell Sat Oct 14 10:44:32 1995
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Date: Sat, 14 Oct 1995 09:08:59 -0700 (PDT)
From: Bill Mitchell <mitchell@mdd.comm.mot.com>
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Subject: tgetent() returns unexpected error return codes
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PACKAGE:  ncurses-developer, git
VERSION:  1.9.4-0, 2.3.7-3

I'm not a curses programmer, but I maintain the git package,
which uses libncurses.  I see that the termcap(3ncurses)
man page says:

RETURN VALUE
       Routines	that  return  an integer return ERR upon failure
       and OK (SVr4 only specifies "an integer value  other  than
       ERR") upon successful completion.

However, I also see that the SunOS curses(3X) man page says:

     tgetent() extracts the entry for terminal name into  the  bp
     buffer, with the current size of the tty (usually a window).
     This allows pre-SunWindows programs to run in  a  window  of
     arbitrary  size.   bp  should  be a character buffer of size
     1024 and must be retained through all  subsequent  calls  to
     tgetnum(),  tgetflag(), and tgetstr().  tgetent() returns -1
     if it cannot open the termcap() file, 0 if the terminal name
     given  does  not  have an entry, and 1 if all goes well.  It
     will look in the environment for  a  TERMCAP  variable.   If
     found,  and  the  value does not begin with a slash, and the
     terminal type name is the same  as  the  environment  string
     TERM,  the  TERMCAP  string  is  used instead of reading the
     termcap file.  If it does begin with a slash, the string  is
     used  as  a  path  name  rather than /etc/termcap.  This can
     speed up entry into programs that call tgetent, as  well  as
     to  help  debug new terminal descriptions or to make one for
     your terminal if you cannot  write  the  file  /etc/termcap.
     Note:   if  the  window  size  changes,  the  ``lines''  and
     ``columns'' entries in bp are no longer  correct.   See  the
     SunView 1  Programmer's  Guide for details regarding [how to
     handle] this.

and this SunOS-style (BSD?) behavior is what is expected by the
git(1) code.  This results in a misleading error message from git(1)
if a terminal is specified which cannot be found in the database.
I imagine that other software probably expects this behavior as
well.

Is there any chance of ncurses being enhanced to return SunOS-style
return values, or should I modify the git package for compatability
with the current, less informative, SVr4-style return values and
submit the change to the git author?

mitchell@mdd.comm.mot.com (Bill Mitchell)