lead/lag fails: Value of SET_STRING_ELT() must be a 'CHARSXP' not a 'character'

[r2evans]

This works:

library(dplyr)
mtcars %>%
    mutate(xx=LETTERS[gear]) %>%
    filter(xx==lag(xx))

This fails:

mtcars %>%
    mutate(xx=LETTERS[gear]) %>%
    filter(xx==lag(xx, default='foo'))
## Error in filter_impl(.data, dots) : 
##   Value of SET_STRING_ELT() must be a 'CHARSXP' not a 'character'

Variants:

• works: ... %>% filter(carb == lag(carb, default=1)) (a numeric)
• fails: ... %>% filter(as.character(xx) == lag(xx, default='foo'))
• works: ... %>% filter(xx == lag(as.character(xx), default='foo')) (just by adding as.character)

This behavior is new in dplyr-0.4.3, I think.

sessionInfo()
## R version 3.2.2 (2015-08-14)
## Platform: x86_64-w64-mingw32/x64 (64-bit)
## Running under: Windows 8 x64 (build 9200)
## 
## locale:
## [1] LC_COLLATE=English_United States.1252 
## [2] LC_CTYPE=English_United States.1252   
## [3] LC_MONETARY=English_United States.1252
## [4] 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] dplyr_0.4.3 readr_0.1.1
## 
## loaded via a namespace (and not attached):
##  [1] compiler_3.2.2  lazyeval_0.1.10 magrittr_1.5    R6_2.1.1       
##  [5] assertthat_0.1  parallel_3.2.2  DBI_0.3.1       tools_3.2.2    
##  [9] htmltools_0.2.6 Rcpp_0.12.0     rmarkdown_0.8   digest_0.6.8