[Rd] Graphic parameters with length zero in grid cause R to crash

[Bob Rudis]

Reproduced on latest Catalina beta and R 4.0.0 and latest RStudio
devel build (it crashes the session).

On Tue, May 19, 2020 at 7:39 AM Gu, Zuguang <z.gu using dkfz-heidelberg.de> wrote:
>
> Hi,
>
>
> I found in grid package, if the graphic parameters have zero length, R crashes. In the
>
> following code, I only tested `grid.rect()` and the `fill` parameter, but I think it should
>
> be similar as other grid graphic functions.
>
>
> In `gpar()` function, the graphic parameters are not allowed to have zero length, but
> we can make them with zero length by first generating a `gpar` object and then subsetting
> with zero length index, such as follows:
>
> ```
> > library(grid)
> > gp = gpar(fill = 1)
> > grid.rect(gp = gp[integer(0)])
> ```
>
> After Executing the code, R crashes with message "Floating point exception: 8?".
>
> If I set the value of `fill` to an integer, the following code causes an error with a
> not informative error message.
>
> > library(grid)
> > gp = gpar(fill = as.integer(1))
> > grid.rect(gp = gp[integer(0)])
> Error in grid.Call.graphics(C_rect, x$x, x$y, x$width, x$height, resolveHJust(x$just,  :
>   numerical color values must be >= 0, found -192882464
>
> But sometimes it also causes R to crash.
>
>
> My session info:
>
>
> ```
>
> > sessionInfo()
> R version 4.0.0 (2020-04-24)
> Platform: x86_64-apple-darwin17.0 (64-bit)
> Running under: macOS Catalina 10.15.4
>
> Matrix products: default
> BLAS:   /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRblas.dylib
> LAPACK: /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRlapack.dylib
>
> locale:
> [1] en_GB.UTF-8/en_GB.UTF-8/en_GB.UTF-8/C/en_GB.UTF-8/en_GB.UTF-8
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
>
> other attached packages:
> [1] colorout_1.2-2
>
> loaded via a namespace (and not attached):
> [1] compiler_4.0.0?
> ```
>
>
> Best regards,
> Zuguang Gu?
>
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-devel using r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel