Possible Bug: file.exists() Function. Due to UTF-8 Encoding differences on Windows between R 4.0.1 and R 3.6.3?

Hi Tomas,

I received a report about R 4.0.0 in the knitr package
(https://github.com/yihui/knitr/issues/1840), and I think it is
related to the issue here. I created a minimal reproducible example
below:

owd = setwd(tempdir())
z = 'K\u00e4sch.txt'
file.create(z)
list.files()
file.exists(list.files())
setwd(owd)

Output:

owd = setwd(tempdir())
z = 'K\u00e4sch.txt'
file.create(z)

[1] TRUE

list.files()

[1] "K?sch.txt"

file.exists(list.files())

[1] FALSE

setwd(owd)

I wonder if it is expected that file.exists() returns FALSE here.

sessionInfo()

R version 4.0.1 (2020-06-06)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252
[3] LC_MONETARY=English_United States.1252 LC_NUMERIC=C
[5] LC_TIME=English_United States.1252
system code page: 936

FWIW, I also tested Chinese characters in the variable `z` above, and
file.exists() returns TRUE only after I Sys.setlocale(, "Chinese").

Regards,
Yihui

On Thu, Jun 11, 2020 at 3:11 AM Tomas Kalibera <tomas.kalibera at gmail.com> wrote:

Dear Juan,

I don't see what is the problem from your report. Please try to create a
minimal but complete reproducible example that does not use the renv
package. Perhaps you could use the R debugger (e.g. via
options(error=recover)) to find out what is the argument that
file.exists() has been called with. And then you could try just to call
file.exists() directly with that argument to trigger the problem.

It may be that the argument has been corrupted/is invalid in the current
native encoding. If that is the case, the next step would be to find out
who corrupted it (renv, R, something else). The error is displayed when
a path name cannot be converted from the current native encoding to
UTF16-LE.

The experimental support for UTF-8 as native encoding on Windows 10 is
only available in a custom build of R, like the one I linked from my
blog post.

Thanks
Tomas



On 6/10/20 1:06 PM, Juan Telleria Ruiz de Aguirre wrote:

Dear R Developers,

I am having an issue with the renv package and R 4.0.1, which I
suspect is related to base R and not the renv package itself, as with
R 3.6.3 such an "error" does not appear.

The error is raised by a file.exists() path, and path
"C:\Users\J-tel\Documents", which in R 3.6.3 is read correctly, but in
R 4.0.1 fails (Probably because of the "-" symbol), and I suspect it
might be related with the new UTF-8 usage on Windows 10?
(https://developer.r-project.org/Blog/public/2020/05/02/utf-8-support-on-windows/index.html)

I have also checked file.exists() function and its internals, and seem
not to have happened changes in the meanwhile within them:

https://github.com/wch/r-source/blob/0e3b3182f87a60af4b0293a5410dde680b910f49/src/library/base/R/files.R
https://github.com/search?q=SEXP%20attribute_hidden%20do_fileexists+repo:wch/r-source&type=Code

Error Details:

renv::init()

Error in file.exists(children) :
    file name conversion problem -- name too long?

traceback()

14: file.exists(children)
13: renv_dependencies_find_dir_children(path, root)
12: renv_dependencies_find_dir(path, root)
11: FUN(X[[i]], ...)
10: lapply(path, renv_dependencies_find_impl, root = root)
9: renv_dependencies_find(path, root)
8: (function (path = getwd(), root = NULL, ..., progress = TRUE,
         errors = c("reported", "fatal", "ignored"), dev = FALSE)
     {
         path <- renv_path_normalize(path, winslash = "/", mustWork = TRUE)
         root <- root %||% renv_dependencies_root(path)
         if (exists(path, envir = `_renv_dependencies`))
             return(get(path, envir = `_renv_dependencies`))
         renv_dependencies_begin(root = root)
         on.exit(renv_dependencies_end(), add = TRUE)
         dots <- list(...)
         if (identical(dots[["quiet"]], TRUE)) {
             progress <- FALSE
             errors <- "ignored"
         }
         files <- renv_dependencies_find(path, root)
         deps <- renv_dependencies_discover(files, progress, errors)
         renv_dependencies_report(errors)
         deps
     })(path, progress = FALSE, errors = errors, dev = TRUE)
7: eval(call, envir = parent.frame(2))
6: eval(call, envir = parent.frame(2))
5: delegate(renv_dependencies_impl)
4: dependencies(path, progress = FALSE, errors = errors, dev = TRUE)
3: withCallingHandlers(dependencies(path, progress = FALSE, errors = errors,
         dev = TRUE), renv.dependencies.error =
renv_dependencies_error_handler(message,
         errors))
2: renv_dependencies_scope(project, action = "init")
1: renv::init()

renv::diagnostics()

Diagnostics Report -- renv [0.10.0]
===================================

# Session Info =======================
R version 4.0.1 (2020-06-06)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 18362)

Matrix products: default

locale:
[1] LC_COLLATE=Spanish_Spain.1252  LC_CTYPE=Spanish_Spain.1252
[3] LC_MONETARY=Spanish_Spain.1252 LC_NUMERIC=C
[5] LC_TIME=Spanish_Spain.1252

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

other attached packages:
[1] renv_0.10.0

loaded via a namespace (and not attached):
   [1] compiler_4.0.1   rsconnect_0.8.16 htmltools_0.4.0  tools_4.0.1
   [5] yaml_2.2.1       Rcpp_1.0.4.6     rmarkdown_2.2    knitr_1.28
   [9] xfun_0.14        digest_0.6.25    packrat_0.5.0    rlang_0.4.6
[13] evaluate_0.14

# Project ============================
Project path: "~/Test2"

# Status =============================

# Lockfile ===========================
This project has not yet been snapshotted: 'renv.lock' does not exist.

# Library ============================
The project library "~/Test2/renv/library/R-4.0/x86_64-w64-mingw32"
does not exist.

# Dependencies =======================

# User Profile =======================
[no user profile detected]

# Settings ===========================
List of 6
   $ external.libraries       : chr(0)
   $ ignored.packages         : chr(0)
   $ package.dependency.fields: chr [1:3] "Imports" "Depends" "LinkingTo"
   $ snapshot.type            : chr "implicit"
   $ use.cache                : logi TRUE
   $ vcs.ignore.library       : logi TRUE

# Options ============================
List of 1
   $ renv.verbose: logi TRUE

# Environment Variables ==============
HOME        = C:\Users\J-tel\OneDrive\Documents
LANG        = <NA>
R_LIBS      = <NA>
R_LIBS_SITE = <NA>
R_LIBS_USER = C:/Users/J-tel/OneDrive/Documents/R/win-library/4.0

# PATH ===============================
- C:\rtools40\usr\bin
- C:\Program Files\R\R-4.0.1\bin\x64
- C:\ProgramData\Miniconda3
- C:\ProgramData\Miniconda3\Library\mingw-w64\bin
- C:\ProgramData\Miniconda3\Library\usr\bin
- C:\ProgramData\Miniconda3\Library\bin
- C:\ProgramData\Miniconda3\Scripts
- C:\ProgramData\Oracle\Java\javapath
- C:\WINDOWS\system32
- C:\WINDOWS
- C:\WINDOWS\System32\Wbem
- C:\WINDOWS\System32\WindowsPowerShell\v1.0\
- C:\WINDOWS\System32\OpenSSH\
- C:\Program Files\MiKTeX 2.9\miktex\bin\x64\
- C:\ProgramData\Miniconda3\Scripts\conda.exe

# Cache ==============================
There are a total of 0 package(s) installed in the renv cache.
Cache path: "C:/Users/J-tel/AppData/Local/renv/cache/v5/R-4.0/x86_64-w64-mingw32"

System Information:

R.Version()

$platform
[1] "x86_64-w64-mingw32"

$arch
[1] "x86_64"

$os
[1] "mingw32"

$system
[1] "x86_64, mingw32"

$status
[1] ""

$major
[1] "4"

$minor
[1] "0.1"

$year
[1] "2020"

$month
[1] "06"

$day
[1] "06"

$`svn rev`
[1] "78648"

$language
[1] "R"

$version.string
[1] "R version 4.0.1 (2020-06-06)"

$nickname
[1] "See Things Now"

Thank you,
Juan