Bug Report and Enhanced text question

[Chris K <gnu...@li...>]

Hi,

  In considering whether to add enhanced text to port.trm, I have a question:

The usual enhanced_recursion calls will need feedback about the text layout size
from the terminal driver.  If a terminal decided to handle the enhanced text
codes internally in the term->put_text call, without using the
enhanced_rercusion, would it still need to send any information to gnuplot about
the text size?

Also, in looking around to add enhanced text to port.trm, I was reading the
documentation in "gnuplot> help enhanced" and comparing that to the parser in
term.c and I found a contradiction.

In the help text it claims:

> (The '/' character MUST be the first character after the '{'.)

But in term.c (edited to clarity) in the enhanced_recursion routine:

>         switch (*p) {
>         case '{'  :
>             {
>                 while (*++p == ' '); /* Line I will call SKIPPY */
>                 if (overprint == 2) {
>                     ovp = (float)strtod(p,&p);
>                     if (term->flags & TERM_IS_POSTSCRIPT)
>                         base = ovp*f;
>                     else
>                         base += ovp*f;
>                 }
>                 --p;
>                 if (*++p == '/') {

Which clearly skips spaces after each opening brace.  So the "MUST" in the help
and the code are in conflict.  A related documentation / parser mismatch error is:

>  You can change the font for one or
>  both strings ('~a{.5 /*.2 o}'---an 'a' with a one-fifth-size 'o' on top---and
>  the space between the number and the slash is necessary), but you can't
>  change it after the beginning of the string.

Which from reading the code and performing tests is wrong -- you MUST NOT put a
space between the vertical shift and the '/'.

So it looks like the line I call SKIPPY used to be after the (overprint==2)
parsing code and has been cut and pasted to now be before the (overprint==2)
code.  This causes both of the differences with the help text documentation.

There are several fixes:
*) Move SKIPPY back to below the (overprint==2) block, keep help text
*) Change the help text to reflect the new behavior
*) Put a copy of SKIPPY below the (overprint==2) block, change help text
*) Delete SKIPPY and change the help text


Also, I am amused that strtod is parsing the numbers for things like the font
size.  Thus "{/=-0x.Deap1Rising}" would print "Rising" with a font size of -1.73926

This should be left undocumented.  As should "/=INF" and "/=NaN".

Finally, the strtod calls all are prefixed with (float) which means it ought to
be a strtof call, so I assume this was done for portability reasons.