[PATCH 1/2] readline_simple: return -1 if getc fails

[Lucas Stach]

Am Dienstag, den 08.08.2017, 11:20 -0400 schrieb Gaël PORTAY:
> Hi Lucas,
> 
> On Tue, Aug 08, 2017 at 09:51:54AM +0200, Lucas Stach wrote:
> > Am Montag, den 07.08.2017, 18:10 -0400 schrieb Gaël PORTAY:
> > > The getc function may return an errno code if an error happens.
> > > 
> > > This patch prevents readline from printing a non printable character and
> > > from looping to infinity and beyong.
> > > 
> > > Signed-off-by: Gaël PORTAY <gael.portay at savoirfairelinux.com>
> > > ---
> > >  lib/readline_simple.c | 2 ++
> > >  1 file changed, 2 insertions(+)
> > > 
> > > diff --git a/lib/readline_simple.c b/lib/readline_simple.c
> > > index c4d3d240e..1283c9602 100644
> > > --- a/lib/readline_simple.c
> > > +++ b/lib/readline_simple.c
> > > @@ -58,6 +58,8 @@ int readline (const char *prompt, char *line, int len)
> > >  
> > >  	for (;;) {
> > >  		c = getchar();
> > > +		if (c < 0)
> > > +			return (-1);
> > 
> > I don't like made up error codes. Is there any reason why we couldn't
> > just pass through the negative error code from getchar?
> > 
> 
> The thing here is that getchar() may return an error, and that error is not
> tested. This causes readline to print the character 0xea (-EINVAL) which is not
> printable.

So why wouldn't the following fix the issue?

signed char c;

if (c < 0)
	return c;

Regards,
Lucas