When `pattern` manages NAs in `fmt_icon() |> cols_merge()`, `NA` gets repeatedly appended to the value.

[JoFrhwld]

Prework

• Read and agree to the code of conduct and contributing guidelines.
• If there is already a relevant issue, whether open or closed, comment on the existing thread instead of posting a new issue.

Description

After passing a table to fmt_icon(), if I then cols_merge() with a pattern that takes into account NAs, a very large number of NA get appended to cells that don't have NAs.

Reproducible example

library(gt)

data.frame(
  x = c("dice-one", "dice-two", "dice-three"),
  y = c("dice-one", NA, "dice-three")
) |> 
  gt() ->
  base_table

This works

Without using fmt_icon(), this works as expected.

base_table |> 
  cols_merge(
    columns = everything(),
    pattern = "({1}<< {2}>>)"
  )

This does not work

It also takes a while to run, I assume because of all the NAs that are getting appended.

base_table |> 
  fmt_icon() |> 
  cols_merge(
    columns = everything(),
    pattern = "({1}<< {2}>>)"
  )

Inspecting the html output for the first row, there were 49,547 NAs appended to the cell.

Expected result

I expected output similar to the working example, but with the icons instead of the names of the icons.

Session info

R version 4.4.0 (2024-04-24)
Platform: aarch64-apple-darwin20
Running under: macOS Sonoma 14.2

Matrix products: default
BLAS:   /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib 
LAPACK: /Library/Frameworks/R.framework/Versions/4.4-arm64/Resources/lib/libRlapack.dylib;  LAPACK version 3.12.0

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

time zone: America/New_York
tzcode source: internal

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

other attached packages:
[1] gt_0.11.0

loaded via a namespace (and not attached):
 [1] digest_0.6.37     utf8_1.2.4        R6_2.5.1          fastmap_1.2.0    
 [5] tidyselect_1.2.1  xfun_0.47         magrittr_2.0.3    glue_1.7.0       
 [9] tibble_3.2.1      knitr_1.48        htmltools_0.5.8.1 pkgconfig_2.0.3  
[13] dplyr_1.1.4       generics_0.1.3    lifecycle_1.0.4   xml2_1.3.6       
[17] cli_3.6.3         fansi_1.0.6       vctrs_0.6.5       withr_3.0.1      
[21] renv_1.0.7        compiler_4.4.0    rstudioapi_0.16.0 tools_4.4.0      
[25] pillar_1.9.0      rlang_1.1.4