From ac170a08332e4aeeea78fc68ed6d54abc456f08e Mon Sep 17 00:00:00 2001
From: Stephan Lachnit <stephanlachnit@debian.org>
Date: Mon, 25 Apr 2022 13:48:33 +0200
Subject: [PATCH 1/3] feature: add support for GLFM math blocks

This add supports for GLFM's math blocks [1] using hugo's Markdown
render hooks [2].

[1]: https://docs.gitlab.com/ee/user/markdown.html#math
[2]: https://gohugo.io/templates/render-hooks/#render-hooks-for-code-blocks

Signed-off-by: Stephan Lachnit <stephanlachnit@debian.org>
---
 layouts/_default/_markup/render-codeblock-math.html        | 3 +++
 .../en/docs/adding-content/diagrams-and-formulae/index.md  | 7 +++++++
 2 files changed, 10 insertions(+)
 create mode 100644 layouts/_default/_markup/render-codeblock-math.html

diff --git a/layouts/_default/_markup/render-codeblock-math.html b/layouts/_default/_markup/render-codeblock-math.html
new file mode 100644
index 0000000000..149a1ae188
--- /dev/null
+++ b/layouts/_default/_markup/render-codeblock-math.html
@@ -0,0 +1,3 @@
+<p>$$
+{{ .Inner | safeHTML }}
+$$</p>
diff --git a/userguide/content/en/docs/adding-content/diagrams-and-formulae/index.md b/userguide/content/en/docs/adding-content/diagrams-and-formulae/index.md
index 859ed7e9a0..66abf3a82e 100644
--- a/userguide/content/en/docs/adding-content/diagrams-and-formulae/index.md
+++ b/userguide/content/en/docs/adding-content/diagrams-and-formulae/index.md
@@ -35,6 +35,13 @@ $$\tag*{(1)} P(E) = {n \choose k} p^k (1-p)^{n-k}$$
 The probability of getting \\(k\\) heads when flipping \\(n\\) coins is:
 $$\tag*{(1)}  P(E) = {n \choose k} p^k (1-p)^{n-k}$$
 
+You can also use [GLFM's math blocks](https://docs.gitlab.com/ee/user/markdown.html#math) (requires hugo 0.93 or newer):
+````markdown
+```math
+\tag*{(1)} P(E) = {n \choose k} p^k (1-p)^{n-k}
+```
+````
+
 {{% alert title="Tip" %}}
 This [wiki page](https://en.wikibooks.org/wiki/LaTeX/Mathematics) provides in-depth information about typesetting mathematical formulae using the \\(\LaTeX\\) typesetting system.
 {{% /alert %}}

From 62d5bef476b3ac938491c8e291af59b532f28c5c Mon Sep 17 00:00:00 2001
From: Stephan Lachnit <stephanlachnit@debian.org>
Date: Fri, 30 Sep 2022 13:28:19 +0200
Subject: [PATCH 2/3] doc: put KaTeX delimiters in own line

Signed-off-by: Stephan Lachnit <stephanlachnit@debian.org>
---
 .../en/docs/adding-content/diagrams-and-formulae/index.md | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/userguide/content/en/docs/adding-content/diagrams-and-formulae/index.md b/userguide/content/en/docs/adding-content/diagrams-and-formulae/index.md
index 66abf3a82e..94d81b5c5d 100644
--- a/userguide/content/en/docs/adding-content/diagrams-and-formulae/index.md
+++ b/userguide/content/en/docs/adding-content/diagrams-and-formulae/index.md
@@ -29,11 +29,15 @@ The following code sample produces an introductory text line followed by a formu
 
 ```tex
 The probability of getting \\(k\\) heads when flipping \\(n\\) coins is:
-$$\tag*{(1)} P(E) = {n \choose k} p^k (1-p)^{n-k}$$
+$$
+\tag*{(1)} P(E) = {n \choose k} p^k (1-p)^{n-k}
+$$
 ```
 
 The probability of getting \\(k\\) heads when flipping \\(n\\) coins is:
-$$\tag*{(1)}  P(E) = {n \choose k} p^k (1-p)^{n-k}$$
+$$
+\tag*{(1)}  P(E) = {n \choose k} p^k (1-p)^{n-k}
+$$
 
 You can also use [GLFM's math blocks](https://docs.gitlab.com/ee/user/markdown.html#math) (requires hugo 0.93 or newer):
 ````markdown

From 20b2801d169c2f9bca6976b5264d0af684bd1d18 Mon Sep 17 00:00:00 2001
From: Stephan Lachnit <stephanlachnit@debian.org>
Date: Sat, 8 Oct 2022 10:43:41 +0200
Subject: [PATCH 3/3] Use user-defined delimiters for GLFM math blocks

Signed-off-by: Stephan Lachnit <stephanlachnit@debian.org>
---
 .../_default/_markup/render-codeblock-math.html | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/layouts/_default/_markup/render-codeblock-math.html b/layouts/_default/_markup/render-codeblock-math.html
index 149a1ae188..831b9a2f6b 100644
--- a/layouts/_default/_markup/render-codeblock-math.html
+++ b/layouts/_default/_markup/render-codeblock-math.html
@@ -1,3 +1,16 @@
-<p>$$
+{{/* set default delimiters */}}
+{{ $delimiter_left := "$$" }}
+{{ $delimiter_right := "$$" }}
+
+{{/* override delimiters if set in config file */}}
+{{ with $.Page.Site.Params.katex.options.delimiters }}
+  {{ range first 1 ( where . "display" true ) }}
+    {{ $delimiter_left = index . "left" }}
+    {{ $delimiter_right = index . "right" }}
+  {{ end }}
+{{end}}
+
+{{/* output of equation */}}
+<p>{{ $delimiter_left }}
 {{ .Inner | safeHTML }}
-$$</p>
+{{ $delimiter_right }}</p>