Geom_point borders in ggplot2 2.0.0

Question

In the most recent version of ggplot2 , there seems to have been a change in the way geom_point .

For example, if I try to perform alpha shading, I get the following view:

 library(ggplot2) ggplot(mtcars) + geom_point(aes(wt, qsec), size = 8, stroke = 0, alpha = .3) 

How can I get ggplot to mimic its earlier behavior and dots appear without any border?

Edit:

As I said, this happens in:

latest ggplot2 version

 > sessionInfo() R version 3.2.3 (2015-12-10) Platform: x86_64-w64-mingw32/x64 (64-bit) Running under: Windows >= 8 x64 (build 9200) locale: [1] LC_COLLATE=English_United States.1252 LC_CTYPE=English_United States.1252 LC_MONETARY=English_United States.1252 LC_NUMERIC=C [5] LC_TIME=English_United States.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] ggplot2_2.0.0 loaded via a namespace (and not attached): [1] labeling_0.3 colorspace_1.2-6 scales_0.3.0 plyr_1.8.3 tools_3.2.3 gtable_0.1.2 Rcpp_0.12.2 grid_3.2.3 munsell_0.4.2 

Edit 2 :

These borders are also found in github version: ggplot2_2.0.0.9000

Answer 1

In an email to ggplot2 listserve, Hadley mentions that "geom_point () now uses form 19 instead of 16. This looks much better on the default Linux graphics device (it is very slightly smaller than the old point, but this should not affect any graphics significantly )

 library(ggplot2) ggplot(mtcars) + geom_point(aes(wt, qsec), size = 8, stroke = 0, shape=16, alpha = .3)