R devel - May 2020 - edit() doubles backslashes when keep.source=TRUE

Is it just my installation or does edit() (or fix(), etc.) in R-4.0.0
double all the backslashes when options(keep.source=TRUE)?  E.g.,
> options(keep.source=TRUE)
> f <- function(x) { cat("\t", x, "\n",
sep="") }
> edit(f) # exit the editor without making any changes
The editor (vi or notepad) shows doubled backslashes
    function(x) { cat("\\t", x, "\\n", sep="") }
as does the return value of edit().

If I set options(keep.source=FALSE) before defining 'f' or remove
t's
'srcref' attribute then the backslashes are left alone.

Bill Dunlap
TIBCO Software
wdunlap tibco.com

	[[alternative HTML version deleted]]

I can confirm this changed behaviour. I just compared R-3.6.3 with
yesterday's R-devel. Using R-devel, the tempfile opened by the editor
(Emacs for me, but shouldn't matter) contains doubled backslashes.

This could be related to

https://bugs.r-project.org/bugzilla/show_bug.cgi?id=17800

Best regards,

	Sebastian


Am 15.05.20 um 03:50 schrieb William Dunlap via R-devel:
> Is it just my installation or does edit() (or fix(), etc.) in R-4.0.0
> double all the backslashes when options(keep.source=TRUE)?  E.g.,
> 
>> options(keep.source=TRUE)
>> f <- function(x) { cat("\t", x, "\n",
sep="") }
>> edit(f) # exit the editor without making any changes
> The editor (vi or notepad) shows doubled backslashes
>     function(x) { cat("\\t", x, "\\n",
sep="") }
> as does the return value of edit().
> 
> If I set options(keep.source=FALSE) before defining 'f' or remove
t's
> 'srcref' attribute then the backslashes are left alone.
> 
> Bill Dunlap
> TIBCO Software
> wdunlap tibco.com
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>

>>>>> Sebastian Meyer 
>>>>>     on Fri, 15 May 2020 10:47:55 +0200 writes:
    > I can confirm this changed behaviour. I just compared R-3.6.3 with
    > yesterday's R-devel. Using R-devel, the tempfile opened by the
editor
    > (Emacs for me, but shouldn't matter) contains doubled backslashes.

    > This could be related to

        > https://bugs.r-project.org/bugzilla/show_bug.cgi?id=17800

Yes, indeed, I'm sure this is the same; an inadvertent bug indeed.

    > Best regards,
    > Sebastian

... and  "just the usual"

<whining>

    Why does nobody anymore  help R development by working with
    "R-devel", or at least then the alpha, beta and the "RC"
    (Release Candidate) versions that we release daily for about one
    month before the final release?

    Notably a highly staffed enterprise such as Rstudio (viz the bug
    report 17800 above), but also others could really help by
    starting to use the "next version" of R on a routine basis ...

<whining/>

Still: Thank you, of course,
 Bill Dunlap, and Sebastian and Jonathan (PR 17800)

Martin

    > Am 15.05.20 um 03:50 schrieb William Dunlap via R-devel:
    >> Is it just my installation or does edit() (or fix(), etc.) in
R-4.0.0
    >> double all the backslashes when options(keep.source=TRUE)?  E.g.,
    >> 
    >>> options(keep.source=TRUE)
    >>> f <- function(x) { cat("\t", x, "\n",
sep="") }
    >>> edit(f) # exit the editor without making any changes
    >> The editor (vi or notepad) shows doubled backslashes
    >> function(x) { cat("\\t", x, "\\n",
sep="") }
    >> as does the return value of edit().
    >> 
    >> If I set options(keep.source=FALSE) before defining 'f' or
remove t's
    >> 'srcref' attribute then the backslashes are left alone.
    >> 
    >> Bill Dunlap
    >> TIBCO Software
    >> wdunlap tibco.com

Thanks for reporting this, it is a bug, now fixed in R-devel and 
R-patched (PR#17800).

Best
Tomas

On 5/15/20 3:50 AM, William Dunlap via R-devel wrote:
> Is it just my installation or does edit() (or fix(), etc.) in R-4.0.0
> double all the backslashes when options(keep.source=TRUE)?  E.g.,
>
>> options(keep.source=TRUE)
>> f <- function(x) { cat("\t", x, "\n",
sep="") }
>> edit(f) # exit the editor without making any changes
> The editor (vi or notepad) shows doubled backslashes
>      function(x) { cat("\\t", x, "\\n",
sep="") }
> as does the return value of edit().
>
> If I set options(keep.source=FALSE) before defining 'f' or remove
t's
> 'srcref' attribute then the backslashes are left alone.
>
> Bill Dunlap
> TIBCO Software
> wdunlap tibco.com
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel