Source code block with < and > not generated correctly

[fekir]

Consider following minimal document

= dummy
fekir

[source, cpp]
----
constexpr const node<4> tree
{
	node<4 >
	{
	}
};

constexpr const node<4> tree2
{
	node<4>
	{
	}
};
----

with Asciidoctor 2.0.16 [https://asciidoctor.org] Runtime Environment (ruby 2.7.4p191 (2021-07-07 revision a21a3b7d23) [x86_64-linux-gnu]) (lc:UTF-8 fs:UTF-8 in:UTF-8 ex:UTF-8)

the generated HTML looks like (I can eventually attach the file)

dummy
fekir

constexpr const node<4> tree
{
	node<4 >
	{
	}
};

constexpr const node<4> tree2
{
	node(4)
	{
	}
};

Note that in the second code snippet, the last node<4> has been rewritten as node(4).
If I add some space, like in node<4 >, then <> are not replaced by ().

The offending HTML is

constexpr const node<4> tree2
{
	node<b class="[conum]()">(4)</b>
	{
	}
};

instead of

constexpr const node<4> tree
{
	node<4>
	{
	}
};

[elextr]

It looks like the <4> at end of line is being detected as a callout

[mojavelinux]

That's correct. You can disable callouts for a block using the -callouts incremental substitution.

[,cpp,subs=-callouts]
----
constexpr const node<4> tree
{
	node<4 >
	{
	}
};

constexpr const node<4> tree2
{
	node<4>
	{
	}
};
----

To learn more about incremental substitutions, see https://docs.asciidoctor.org/asciidoc/latest/subs/apply-subs-to-blocks/#incremental