Add another test for footnote definitions.

org_test_documents/footnotes/reference_in_definition.org

@@ -0,0 +1,21 @@
+# This test shows that footnote references only count if the definition containing them is rendered.
+
+foo[fn:a:bar]
+
+[fn:a] lorem
+
+[fn:b] ipsum
+
+[fn:d] fizz
+
+[fn:c] dolar
+
+yo[fn:b]
+
+
+hello[fn:c]
+
+
+[fn:e] buzz
+
+sup[fn:d]

org_test_documents/footnotes/simple.org

@@ -0,0 +1,25 @@
+# Test proves that:
+#
+# - Anonymous references with identical content get unique IDs.
+# - Unreferenced footnote definitions are dropped.
+# - Footnote definitions that come before their first reference are dropped.
+
+foo[fn:2:something]
+
+bar[fn::something]
+
+baz[fn::something]
+
+cat[fn::something]
+
+dog[fn:3]
+
+[fn:3] ipsum
+
+[fn:4] lorem
+
+[fn:3] dolar
+
+[fn:5] not referenced
+
+stuff[fn:4] and things