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

[Paul Murrell]

Yeah, that seems not good.

I will take a look.

Thanks for the report!

Paul

On 19/05/20 9:26 pm, Gu, Zuguang 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?
> 
> 
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> 
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-- 
Dr Paul Murrell
Department of Statistics
The University of Auckland
Private Bag 92019
Auckland
New Zealand
64 9 3737599 x85392
paul using stat.auckland.ac.nz
http://www.stat.auckland.ac.nz/~paul/