Fix regression w/ image path processing from absolute to relative (#2554

)

DESCRIPTION

@@ -1,7 +1,7 @@
 Type: Package
 Package: rmarkdown
 Title: Dynamic Documents for R
-Version: 2.26.1
+Version: 2.26.2
 Authors@R: c(
     person("JJ", "Allaire", , "[email protected]", role = "aut"),
     person("Yihui", "Xie", , "[email protected]", role = c("aut", "cre"), comment = c(ORCID = "0000-0003-0645-5666")),
@@ -83,7 +83,8 @@ Suggests:
     tibble,
     vctrs,
     cleanrmd,
-    withr (>= 2.4.2)
+    withr (>= 2.4.2),
+    xml2
 VignetteBuilder: knitr
 Config/Needs/website: rstudio/quillt, pkgdown
 Encoding: UTF-8

NEWS.md

@@ -3,6 +3,8 @@ rmarkdown 2.27
 
 - Provide a global option `rmarkdown.files.suffix` to configure the suffix of the directory for auxiliary files (thanks, @certara-tzweers, #2550). By default, this suffix is `_files`, which can cause HTML output files to be deleted automatically on Microsoft OneDrive or Google Drive. If that is the case for you, you may set a different suffix in your `.Rprofile`, e.g., `options(rmarkdown.files.suffix = "_rmdfiles")`.
 
+- Fix a regression in 2.26 regarding image paths post-processing in `html_document_base()`. Now absolute paths to image in the output directory (`output_dir`) are correctly made relative to the output directory again.
+
 
 rmarkdown 2.26
 ================================================================================

R/base64.R

@@ -1,6 +1,7 @@
 # processes an HTML resource, given a regular expression that locates
 # instances of that resource
 process_html_res <- function(html, reg, processor) {
+  html <- one_string(html)
   m <- gregexpr(reg, html, perl = TRUE, ignore.case = TRUE)
   regmatches(html, m) <- lapply(regmatches(html, m), function(img_src) {
     src <- sub(reg, '\\1', img_src, ignore.case = TRUE)
@@ -10,7 +11,7 @@ process_html_res <- function(html, reg, processor) {
       character(1)
     )
   })
-  html
+  strsplit(html, "\n", fixed = TRUE)[[1]]
 }
 
 process_images <- function(html, processor) {

tests/testthat/test-html_document_base.R

@@ -0,0 +1,60 @@
+# TODO: to remove when switching the package to edition 3
+local_edition(3)
+
+test_that("Absolute path for image from output directory are made relative to output directory", {
+  skip_if_not_pandoc("2.0")
+  skip_if_not_installed("xml2")
+  skip_if_not_installed("withr")
+  rmd <- local_rmd_file(c(
+    "---",
+    "  title: test",
+    "---",
+    "",
+    "```{r}",
+    "#| label: veryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryverylongfilename",
+    "plot(mtcars)",
+    "```"
+  ))
+  # Forcing absolute path for input and output to trigger absolute path for images
+  out <- rmarkdown::render(rmd, "html_document", output_options = list(self_contained = FALSE), output_dir = dirname(rmd), quiet = TRUE)
+  html <- xml2::read_html(out)
+  img <- xml2::xml_find_first(html, ".//img")
+  # is the path correctly made relative to _files ?
+  expect_match(xml2::xml_attr(img, "src"), sprintf("^%s", knitr_files_dir(basename(rmd))))
+})
+
+
+test_that("Absolute path from output_dir from img tag created through pandoc are made relative to output_dir", {
+  skip_if_not_pandoc("2.0")
+  skip_if_not_installed("xml2")
+  skip_if_not_installed("withr")
+  # from https://github.com/r-lib/pkgdown/issues/2341
+  # Issue happens because
+  # - knitr::hook_plot_md_base() will use markdown syntax when no width and height are provided (+ other contextt). Pandoc will convert and add a linebreak
+  #   due to its wrapping config --wrap=auto from pandoc 2.17 which could break our processing
+  # - This won't be the case for .png file for example, as a out.width is computed by knitr internally which trigger <img src=> tag use
+  # - This is why we recreate using gif below
+  #   1. Take the gif from package
+  #   2. Copy it to the fig_path() which will be in output directory
+  #   3. Use include_graphics to include it in knitr, keeping absolute path
+  rmd <- local_rmd_file(c(
+    "---",
+    "  title: test",
+    "---",
+    "",
+    "```{r}",
+    "#| label: veryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryverylongfilename",
+    "gif <- system.file('rmd/h/rmarkdown/rmd_loader.gif', package = 'rmarkdown')",
+    "stopifnot(file.exists(gif))",
+    "file <- knitr::fig_path('.gif')",
+    "dir.create(dirname(file), showWarnings = FALSE, recursive = TRUE)",
+    "file.copy(gif, file)",
+    "knitr::include_graphics(file, rel_path = FALSE)",
+    "```"
+  ))
+  out <- rmarkdown::render(rmd, "html_document", output_options = list(self_contained = FALSE, keep_md = TRUE), output_dir = dirname(rmd), quiet = TRUE)
+  html <- xml2::read_html(out)
+  img <- xml2::xml_find_first(html, ".//img")
+  # # is the path correctly made relative to _files ?
+  expect_match(xml2::xml_attr(img, "src"), sprintf("^%s", knitr_files_dir(basename(rmd))))
+})