Prevent unwanted incrementing of section number in operation macro

See gh-638

spring-restdocs-asciidoctor/src/test/java/org/springframework/restdocs/asciidoctor/AbstractOperationBlockMacroTests.java

@@ -118,7 +118,7 @@ public abstract class AbstractOperationBlockMacroTests {
 	@Test
 	public void includeSnippetInSection() throws Exception {
 		String result = this.asciidoctor.convert(
-				"= A\n\nAlpha\n\n== B\n\nBravo\n\n" + "operation::some-operation[snippets='curl-request']",
+				"= A\n:doctype: book\n:sectnums:\n\nAlpha\n\n== B\n\nBravo\n\n" + "operation::some-operation[snippets='curl-request']\n\n== C\n",
 				this.options);
 		assertThat(result).isEqualTo(getExpectedContentFromFile("snippet-in-section"));
 	}

spring-restdocs-asciidoctor/src/test/resources/operations/snippet-in-section.html

@@ -6,18 +6,24 @@
 </div>
 </div>
 <div class="sect1">
-<h2 id="_b">B</h2>
+<h2 id="_b">1. B</h2>
 <div class="sectionbody">
 <div class="paragraph">
 <p>Bravo</p>
 </div>
 <div class="sect2">
-<h3 id="_b_curl_request">Curl request</h3>
+<h3 id="_b_curl_request">1.1. Curl request</h3>
 <div class="listingblock">
 <div class="content">
 <pre class="highlight"><code class="language-bash" data-lang="bash">$ curl 'http://localhost:8080/' -i</code></pre>
 </div>
 </div>
 </div>
+</div>
+</div>
+<div class="sect1">
+<h2 id="_c">2. C</h2>
+<div class="sectionbody">
+
 </div>
 </div>