hunspell returns a word although it is in the custom dictionary

[ThierryO]

Reproducible example.

library(hunspell)
hunspell(
  "een entiteitsoverschrijdende werking",
  dict = dictionary(lang = "nl_BE", add_words = "entiteitsoverschrijdende")
)

returns the word below but it should return an empty character vector:

[[1]]
[1] "entiteitsoverschrijdende"

Related issue: inbo/checklist#143

Session info:

─ Session info ────────────────────────────────────────────────────────────────────────────────────────────────
 setting  value
 version  R version 4.4.1 (2024-06-14)
 os       Ubuntu 22.04.5 LTS
 system   x86_64, linux-gnu
 ui       RStudio
 language nl_BE:nl
 collate  nl_BE.UTF-8
 ctype    nl_BE.UTF-8
 tz       Europe/Brussels
 date     2024-10-04
 rstudio  2024.09.0+375 Cranberry Hibiscus (desktop)
 pandoc   3.1.8 @ /usr/bin/pandoc

─ Packages ────────────────────────────────────────────────────────────────────────────────────────────────────
 package     * version date (UTC) lib source
 cli           3.6.3   2024-06-21 [1] CRAN (R 4.4.0)
 digest        0.6.37  2024-08-19 [1] CRAN (R 4.4.1)
 fortunes      1.5-4   2016-12-29 [1] CRAN (R 4.4.0)
 hunspell    * 3.0.5   2024-10-04 [1] Github (ropensci/hunspell@05dcaa1)
 pak           0.8.0   2024-08-26 [1] CRAN (R 4.4.1)
 Rcpp          1.0.13  2024-07-17 [1] CRAN (R 4.4.1)
 rstudioapi    0.16.0  2024-03-24 [1] CRAN (R 4.4.0)
 sessioninfo   1.2.2   2021-12-06 [1] CRAN (R 4.4.0)

 [1] /home/thierry/R/x86_64-pc-linux-gnu-library/4.4
 [2] /usr/local/lib/R/site-library
 [3] /usr/lib/R/site-library
 [4] /usr/lib/R/library

───────────────────────────────────────────────────────────────────────────────────────────────────────────────

[hansvancalster]

To help narrow this issue down, it appears to occur with any word passed to add_words that contains the sequence of letters "ij" in it. Could it be an encoding issue? In Dutch, 'ij' is a digraph. Encoding should treat it as two separate characters 'i' and 'j', but legacy (U+0132/0133) for 'IJ'/'ij' exist also.