I think I found the fix for the bug #7795 I reported
yesterday.

I found that there was a difference between decf()
and eef() in math.c, and when I made the change,
the calculator seems to function properly.

The comment for lift_enabled on line 96 is not very
helpful, but I think it determines whether the stack
should be "lifted" when certain keys are pressed.

The diff is very simple:

krylov:contrib/programs/xcalc->diff math.c math.c.orig
400c400
<       if (rpn && lift_enabled)
---
>       if (rpn)

I found two more bugs in xcalc that I fixed.

1) From the man page:

  BUGS
       HP mode:  A bug report claims that the sequence of keys 5,
       ENTER, <- should clear the display, but it doesn't.

This is how _my_ HP calculator works.  Admittedly, it's an 11C
rather than the 10C that's supposedly being emulated, but I
think the behavior is the same.


2) If you use the backspace in rpn mode to erase a decimal
point, the flag that prevents two decimals in a number is
not cleared, so you can't enter the decimal point after
correcting it.


The complete diff for these and the original bug is below.

-Geoffrey



krylov:contrib/programs/xcalc->diff math.c math.c.orig
377,378c377
<       if (entered!=1) {
<         clearf();
---
>       if (entered!=1 || clrdisp)
380,385c379
<       }
<       if (clrdisp)
<         return;
<       if ((int) strlen(dispstr) > 0) {
<         if (dispstr[strlen(dispstr)-1] == '.')
<              Dpoint=0;
---
>       if ((int) strlen(dispstr) > 0)
387d380
<       }
407c400
<       if (rpn && lift_enabled)
---
>       if (rpn)

fixed for next release.

I've applied your patches to the X11R6 in rawhide.  However, this bug still
appears to persist.  If you have a chance, please look at the
X11R6-contrib-3.3.2-7 package in rawhide in the next couple of days and give me
your thoughts.

closed due to lack of additional feedback.  Please reopen if you have more
information.

Apparently, I didn't submit all the diff's in my previous reports.
There are a few more lines below than in my last report.

% diff math.c math.c.orig
3d2
<  * $MIT: contrib/programs/xcalc/math.c,v 3.2 1999/12/14 18:53:00 gjcoram Exp$
18,19d16
<  *
<  *  Geoffrey Coram fixed most of the HP mode bugs.
316,317c313,314
<         entered = 2;
<         clrdisp++;
---
>       entered = 2;
>       clrdisp++;
325c322
<       clrdisp++;
---
>       clrdisp = 0;
330,331c327,328
<         entered = 2;
<         clrdisp++;
---
>       entered = 2;
>       clrdisp++;
369d365
<   memop = keynum;
381,382c377
<       if (entered!=1) {
<         clearf();
---
>       if (entered!=1 || clrdisp)
384,389c379
<       }
<       if (clrdisp)
<         return;
<       if ((int) strlen(dispstr) > 0) {
<         if (dispstr[strlen(dispstr)-1] == '.')
<              Dpoint=0;
---
>       if ((int) strlen(dispstr) > 0)
391d380
<       }
411c400
<       if (rpn && lift_enabled)
---
>       if (rpn)
814d802
<   memop = keynum;

Also, the man page should be updated, since the bug report
in the old man page has been fixed.

% diff xcalc.man xcalc.man.orig
425,426c425,426
< HP mode is not completely debugged.  In particular, the stack is
< not handled properly after errors.
---
> HP mode:  A bug report claims that the sequence of keys 5, ENTER, <-
> should clear the display, but it doesn't.

fixed in rawhide, pkg. version X11R6-contrib-3.3.2-11 and later.