Org reader: More flexible LaTeX environments

Looking at the definition of `org-element-latex-environment-parser`, one
sees that Org allows arbitrary arguments to LaTeX environments. In fact,
it parses every char just after `\begin{xxx}` until `\end{xxx}` as
content for the environment, so all the following examples are valid
environments:

```org
\begin{equation} e = mc^2 \end{equations}
```
```org
\begin{tikzcd}[ampersand replacement=\&]
	A \& B \\
	C \& D
	\arrow[from=1-1, to=1-2]
	\arrow["f", from=2-1, to=2-2]
\end{tikzcd}
```

2 files changed, 22 insertions, 1 deletions

diff --git a/test/Tests/Readers/Org/Block.hs b/test/Tests/Readers/Org/Block.hs
index 4f3038f93..fd11b9ad7 100644
--- a/test/Tests/Readers/Org/Block.hs
+++ b/test/Tests/Readers/Org/Block.hs
@@ -186,6 +186,27 @@ tests =
                , "\\end{equation}"
                ])
 
+    , "One-line LaTeX fragment" =:
+      "\\begin{equation} 2 + 3 \\end{equation}" =?>
+      rawBlock "latex" "\\begin{equation} 2 + 3 \\end{equation}\n"
+
+    , "LaTeX fragment with more arguments" =:
+      T.unlines [ "\\begin{tikzcd}[ampersand replacement=\\&]"
+                , "  A \\& B \\\\"
+                , "  C \\& D"
+                , "  \\arrow[from=1-1, to=1-2]"
+                , "  \\arrow[\"f\", from=2-1, to=2-2]"
+                , "\\end{tikzcd}"
+                ] =?>
+      rawBlock "latex"
+      (T.unlines [ "\\begin{tikzcd}[ampersand replacement=\\&]"
+                 , "  A \\& B \\\\"
+                 , "  C \\& D"
+                 , "  \\arrow[from=1-1, to=1-2]"
+                 , "  \\arrow[\"f\", from=2-1, to=2-2]"
+                 , "\\end{tikzcd}"
+                 ])
+
     , "Convert blank lines in blocks to single newlines" =:
       T.unlines [ "#+begin_html"
                 , ""
diff --git a/test/Tests/Readers/Org/Directive.hs b/test/Tests/Readers/Org/Directive.hs
index 7839cf193..cceed8108 100644
--- a/test/Tests/Readers/Org/Directive.hs
+++ b/test/Tests/Readers/Org/Directive.hs
@@ -250,7 +250,7 @@ tests =
                     , "\\end{equation}"
                     ] =?>
           para (str "\\begin{equation}" <> softbreak <>
-                str "f(x) = x^2" <> softbreak <>
+                text "f(x) = x^2" <> softbreak <>
                 str "\\end{equation}")
         ]
       ]