Re: address@hidden: compilation-previous-error fails if first error is at start of buffer]

[Jan Djärv]

Lennart Borgman (gmail) skrev:
> Nick Roberts wrote:
> >  > > If the compilation buffer begins with error lines right at the top:
> >  > >  > > c:/EmacsW32/etc/EmacsW32Util.html:7:5: Warning: <link> 
> > inserting "type"  > > attribute
> >  > > c:/EmacsW32/etc/EmacsW32Util.html:12:19: Warning: <table> lacks 
> >  > > "summary" attribute
> >  > > c:/EmacsW32/etc/EmacsW32Util.html:29:5: Warning: <table> lacks 
> > "summary"  > > attribute
> >  > >  > > then if point is on second line compilation-previous-error 
> > fails.
> >  > >  >  > What is the error message?
> >
> > Warnings and errors are equivalent in the compilation buffer.  I don't 
> > see how
> > Lennart gets error lines right at the top as I always get the 
> > following four
> > lines:
> >
> >     -*- mode: compilation; default-directory: "~/" -*-
> >     Compilation started at Mon Jan  8 21:22:48
> >
> >     `command used for my compilation'
>
>
> The output is from a library not included in Emacs (actually a version 
> of tidy.el). The output does not have the lines above at the beginning. 
> It would be rather inconvenient if it had, but maybe those line still 
> should be there for some reason?

Yes there is a reason.  Compilation mode uses previous-single-property-change 
to scan backwards to find the correct position to go to.  But if a line begins 
at buffer start, there is no property change and 
previous-single-property-change return nil.

I think you should modify your library to add an empty line at the top, or 
maybe some informative text.

        Jan D.