LaTeX, ansi - escape latex inside highlighting environments

news/changelog-1.7.md

@@ -78,6 +78,7 @@ All changes included in 1.7:
 
 ## `pdf`
 
+- ([#11695](https://github.com/quarto-dev/quarto-cli/issues/11695)): Translate ANSI color codes more carefully inside `highlighting` environments.
 - ([#11835](https://github.com/quarto-dev/quarto-cli/issues/11835)): Take markdown structure into account when detecting minimum heading level.
 - ([#11878](https://github.com/quarto-dev/quarto-cli/issues/11878), [#12085](https://github.com/quarto-dev/quarto-cli/issues/12085)): Correctly fixup raw LaTeX table having an unexpected table env with options (e.g `\begin{table}[!ht]`) to be handled as crossref table.
 - ([#11903](https://github.com/quarto-dev/quarto-cli/issues/11903)): `crossref` configuration like `fig-title` or `tbl-title` now correctly supports multi word values, e.g. `fig-title: 'Supplementary Figure'`.

src/resources/filters/quarto-post/latex.lua

@@ -587,6 +587,23 @@ function render_latex_fixups()
       end
     end,
     CodeBlock = function(code)
+      local function escape_latex(line)
+        -- unfortunately, we can't use stringEscape here (or pandoc.write(..., "latex")
+        -- more generally) because it doesn't preserve multiple spaces, which the 
+        -- "highlighting" environment does
+
+        -- In addition, we have the following tricky situation:
+        --   \ -> \textbackslash{}
+        --   { -> \{
+        --
+        -- these two replacement rules both generate \ and {, and
+        -- so there's no order that works. We need to use a
+        -- unique replacement for \ first.
+
+        -- obtained by a local call to uuid and removing dashes
+        local uuid = "edbdf4a3bc424f5b8ac0e95c92ef5015"
+        return line:gsub("[\\]", uuid):gsub("([{}$%&%_])", "\\%1"):gsub("[%^]", "\\textasciicaret{}"):gsub("[~]", "\\textasciitilde{}"):gsub(uuid, "\\textbackslash{}")
+      end
       if code.text:match("\027%[[0-9;]+m") and #code.classes == 0 then
         local lines = split(code.text, "\n")
         local new_lines = pandoc.List({
@@ -595,6 +612,7 @@ function render_latex_fixups()
         local cur_color = "\\textcolor{black}"
         for _, line in ipairs(lines) do
           local start_color = cur_color
+          line = escape_latex(line)
           line = line:gsub("\027%[([0-9;]+)m", function(n)
             local this_color = "\\textcolor" .. emit_quarto_ansi_color(n)
             cur_color = this_color

tests/docs/smoke-all/2025/04/09/issue-11695.qmd

@@ -0,0 +1,20 @@
+--- 
+title: "foo"
+format: pdf
+keep-tex: true
+---
+
+::: {.cell execution_count=1}
+``` {.python .cell-code}
+stuff
+```
+
+::: {.cell-output .cell-output-error}
+```
+    793         err_msg += '\n' + '\n'.join(remarks)
+```
+```
+Bad but handled somehow: \n
+```
+:::
+:::