libcurl error when using htmlwidgets::saveWidget along with plotly::partial_bundle without an internet connection

從錯誤堆疊中出現的 plotly::partial_bundle 和 verify_partial_bundle 開始，並在離線時使用 htmlwidgets::saveWidget 重現該範例。追蹤用於下載 CDN bundle 的 curl::curl_download 呼叫，並檢查這些進入點附近現有的測試或範例。當所回報的離線工作流程在沒有主機名稱解析錯誤的情況下具有已定義且經過驗證的行為時，即視為完成。

Running the ?plotly::partial_bundle example without an internet connection available results in the below error.
I think it used to work without accessing https://cdn.plot.ly ?
As a workaround I'm now using curl::has_internet to check whether I can use partial_bundle.

Example:

library(plotly)
p <- plot_ly(x = 1:10, y = 1:10) %>% add_markers()
save_widget <- function(p, f) {
  owd <- setwd(dirname(f))
  on.exit(setwd(owd))
  htmlwidgets::saveWidget(p, f)
  mb <- round(file.info(f)$size / 1e6, 3)
  message("File is: ", mb," MB")
}
f1 <- tempfile(fileext = ".html")
f2 <- tempfile(fileext = ".html")
save_widget(p, f1)
save_widget(partial_bundle(p), f2)

Error:

Error in curl::curl_download(paste0("https://cdn.plot.ly/", bundle_script),  : 
  Could not resolve hostname [cdn.plot.ly]:
Could not resolve host: cdn.plot.ly
11.
stop(e)
10.
raise_libcurl_error(6L, "Could not resolve hostname", "Could not resolve host: cdn.plot.ly",
"https://cdn.plot.ly/plotly-basic-2.25.2.min.js", NULL)
9.
curl::curl_download(paste0("https://cdn.plot.ly/", bundle_script),
tmpfile)
8.
verify_partial_bundle(p)
7.
plotly_build.plotly(p)
6.
plotly_build(p)
5.
htmlwidgets::saveWidget(p, f)
4.
x$elementId %||% paste("htmlwidget", createWidgetId(), sep = "-")
3.
toHTML(widget, standalone = TRUE, knitrOptions = knitrOptions)
2.
htmlwidgets::saveWidget(p, f)
1.
save_widget(partial_bundle(p), f2)

sessionInfo:

R version 4.6.1 (2026-06-24 ucrt)
Platform: x86_64-w64-mingw32/x64
Running under: Windows 10 x64 (build 19045)

Matrix products: default
  LAPACK version 3.12.1

locale:
[1] LC_COLLATE=German_Germany.utf8  LC_CTYPE=German_Germany.utf8    LC_MONETARY=German_Germany.utf8 LC_NUMERIC=C                   
[5] LC_TIME=German_Germany.utf8    

time zone: Europe/Berlin
tzcode source: internal

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

other attached packages:
[1] htmlwidgets_1.6.4 plotly_4.12.1     ggplot2_4.0.3     shiny_1.14.0     

loaded via a namespace (and not attached):
 [1] sass_0.4.10         generics_0.1.4      tidyr_1.3.2         digest_0.6.39       magrittr_2.0.5      evaluate_1.0.5     
 [7] grid_4.6.1          RColorBrewer_1.1-3  fastmap_1.2.0       jsonlite_2.0.0      promises_1.5.0      httr_1.4.8         
[13] purrr_1.2.2         crosstalk_1.2.2     viridisLite_0.4.3   scales_1.4.0        jquerylib_0.1.4     cli_3.6.6          
[19] rlang_1.3.0         withr_3.0.3         cachem_1.1.0        yaml_2.3.12         otel_0.2.0          tools_4.6.1        
[25] memoise_2.0.1       dplyr_1.2.1         httpuv_1.6.17       curl_8.0.0          vctrs_0.7.3         R6_2.6.1           
[31] mime_0.13           lifecycle_1.0.5     fontawesome_0.5.3   pkgconfig_2.0.3     pillar_1.11.1       bslib_0.12.0       
[37] later_1.4.8         gtable_0.3.6        data.table_1.18.6.1 glue_1.8.1          Rcpp_1.1.2          xfun_0.60          
[43] tibble_3.3.1        tidyselect_1.2.1    rstudioapi_0.19.0   knitr_1.51          farver_2.1.2        xtable_1.8-8       
[49] htmltools_0.5.9     rmarkdown_2.31      compiler_4.6.1      S7_0.2.2