read_csv errors if a column name is blank and cols() explicitly names an existing column name

[cjyetman]

csv <- "v1,v2,v3,v4,\n1,2,3,4,"
read_csv(csv)
read_csv(csv, col_types = "iiiii")
read_csv(csv, col_types = cols(.default = "c"))
read_csv(csv, col_types = cols(v1 = col_integer()))

all work as expected, except the last read which results in:

Error: not compatible with STRSXP

yes, CSVs with a final column with no data exist in the wild, ex. subset ESS data exported from the ESS Cumulative Data Wizard (European Social Survey)

R version 3.2.2 (2015-08-14)
Platform: x86_64-apple-darwin13.4.0 (64-bit)
Running under: OS X 10.11.2 (El Capitan)

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] readr_0.2.2

loaded via a namespace (and not attached):
[1] rsconnect_0.4.1.4 tools_3.2.2       Rcpp_0.12.1 

[jennybc]

I'm seeing this behaviour too. In my case the empty unnamed column is in the middle, so I don't think it matters where it appears.

[cjyetman]

@jennybc agreed, it is not specific to unnamed columns at the end, nor does the data need to be empty... just an unnamed column is enough to cause the problem

here's a better example that doesn't imply anything other than an unnamed column...

library("readr")
csv <- "v1,,v3,v4\n1,2,3,4"
read_csv(csv)
read_csv(csv, col_types = "iiii")
read_csv(csv, col_types = cols(.default = "c"))
read_csv(csv, col_types = cols(v1 = col_integer()))

and my session info:

R version 3.2.3 (2015-12-10)
Platform: x86_64-apple-darwin13.4.0 (64-bit)
Running under: OS X 10.11.4 (El Capitan)

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] readr_0.2.2

loaded via a namespace (and not attached):
[1] tools_3.2.3 Rcpp_0.12.3