From cbd7d987fd4f57cec4f1ec284895991c1db9b6a7 Mon Sep 17 00:00:00 2001
From: Morten Piibeleht <morten.piibeleht@gmail.com>
Date: Fri, 19 Aug 2022 18:57:07 +1200
Subject: [PATCH] Handle Markdown.LineBreak in LaTeXWriter

Currently LaTeXWriter throws a MethodError when there are LineBreak
nodes in the Markdown AST (i.e. hard linebreak syntax, with \ at EOL).
This patch makes sure we write out \\ in those cases.
---
 CHANGELOG.md                            | 1 +
 src/Writers/LaTeXWriter.jl              | 3 +++
 test/examples/src.latex_simple/index.md | 6 ++++++
 3 files changed, 10 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c7a0efb859..5ad93ca867 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -26,6 +26,7 @@
 ## Version `v0.27.23`
 
 * ![Enhancement][badge-enhancement] The `native` and `docker` PDF builds now run with the `-interaction=batchmode` (instead of `nonstopmode`) and `-halt-on-error` options to make the LaTeX error logs more readable and to fail the build early. ([#1908][github-1908])
+* ![Bugfix][badge-bugfix] The PDF/LaTeX output now handles hard Markdown line breaks (i.e. `Markdown.LineBreak` nodes). ([#1908][github-1908])
 
 ## Version `v0.27.22`
 
diff --git a/src/Writers/LaTeXWriter.jl b/src/Writers/LaTeXWriter.jl
index 13cd337e16..39cdf3fc51 100644
--- a/src/Writers/LaTeXWriter.jl
+++ b/src/Writers/LaTeXWriter.jl
@@ -701,6 +701,9 @@ function latexinline(io, hr::Markdown.HorizontalRule)
     _println(io, "\\rule{\\textwidth}{1pt}}")
 end
 
+function latexinline(io, hr::Markdown.LineBreak)
+    _println(io, "\\\\")
+end
 
 # Metadata Nodes get dropped from the final output for every format but are needed throughout
 # rest of the build and so we just leave them in place and print a blank line in their place.
diff --git a/test/examples/src.latex_simple/index.md b/test/examples/src.latex_simple/index.md
index fe88160b6c..e826523e9b 100644
--- a/test/examples/src.latex_simple/index.md
+++ b/test/examples/src.latex_simple/index.md
@@ -121,3 +121,9 @@ LaTeXEquation2(raw"""
     \end{array}\right]
 """)
 ```
+
+## `LineBreak` node
+
+This sentence\
+should be over **multiple\
+lines**.