Re: gnuplot reports addition in a fn as an error

[sfeam (E. Merritt) <eam...@gm...>]

On Saturday, 01 December 2012, sfeam (Ethan Merritt) wrote:
> On Saturday, 01 December 2012, pl...@pi... wrote:
> > Hi,
> > 
> > yet more is in the silly errors file.  Gnuplot is will to multiply be 
> > 1.4 but not add it !
> > 
> > gnuplot>  f1(x)=1.4*cos(x/15.0)
> > gnuplot>  f1(x)=1.4+cos(x/15.0)
> >                    ^
> >           ';' expected
> > 
> > 
> > In the terminal, the caret is aligned under the digit "4"
> 
> This bug was fixed by a patch to CVS on 31-October-2012
>         * src/parse.c (parse_reset_after_error) src/parse.h src/util.c:
>         Error exit from inside try_to_get_string() left the internal flags for
>         string parsing in an incorrect state.  Provide a reset routine.
> 
> It could only occur following a separate error in a command containing
> a mis-quoted string constant, which is why it went unnoticed for a while.

Simple test case showing that it is a side effect of a string parsing error:

gnuplot> print 1+2
3
gnuplot> set clabel a"
         undefined variable: a
gnuplot> print 1+2
                ^
         ';' expected
gnuplot> set clabel "a"
gnuplot> print 1+2
3

The bug goes all the way back to version 4.2, but apparently is
sufficiently hard to trigger that it was not reported until 4.6.1

	Ethan