Stop dropping the last line of code when adding line numbers and file…

… doesn't have a concluding newline. Fixes #2521

bikeshed/highlight.py

@@ -469,7 +469,7 @@ def addLineWrappers(doc: t.SpecT, el: t.ElementT, options: LineNumberOptions) ->
                 else:
                     h.appendChild(lineWrapper, node)
                     break
-    if len(lineWrapper) > 0:
+    if not h.isEmpty(lineWrapper):
         h.appendChild(el, h.E.span({"class": "line-no"}))
         h.appendChild(el, lineWrapper)
     # Number the lines

tests/include006.bs

@@ -0,0 +1,16 @@
+<pre class=metadata>
+Title: Foo
+Group: test
+Shortname: foo
+Level: 1
+Status: LS
+ED: http://example.com/foo
+Abstract: Verifying all lines are wrapped when numbered, even when the include file lacks a final newline.
+Editor: Example Editor
+Date: 1970-01-01
+</pre>
+
+<pre class=include-code>
+	path: include006.txt
+	line-numbers: on
+</pre>