Tolerate ported issue without a body

Closes gh-114

Author: wilkinsona

src/main/java/io/spring/githubchangeloggenerator/ChangelogGenerator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2024 the original author or authors.
+ * Copyright 2018-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -32,6 +32,7 @@
 
 import org.springframework.stereotype.Component;
 import org.springframework.util.FileCopyUtils;
+import org.springframework.util.StringUtils;
 
 import io.spring.githubchangeloggenerator.ApplicationProperties.ExternalLink;
 import io.spring.githubchangeloggenerator.ApplicationProperties.IssueSort;
@@ -184,6 +185,9 @@ private Set<User> getContributors(List<Issue> issues) {
 	}
 
 	private Issue getPortedReferenceIssue(Issue issue) {
+		if (!StringUtils.hasText(issue.getBody())) {
+			return issue;
+		}
 		for (PortedIssue portedIssue : this.portedIssues) {
 			List<String> labelNames = issue.getLabels().stream().map(Label::getName).toList();
 			if (labelNames.contains(portedIssue.getLabel())) {

src/test/java/io/spring/githubchangeloggenerator/ChangelogGeneratorTests.java

@@ -135,6 +135,15 @@ void generateWhenHasForwardAndBackPorts() throws Exception {
 		assertChangelog("23").hasContent(from("output-with-no-bugs"));
 	}
 
+	@Test
+	void generateWhenHasPortedIssuesWithNoBody() throws Exception {
+		List<Issue> issues = new ArrayList<>();
+		issues.add(newPortedIssue("Enhancement 1", "2", null, "enhancement-1-url", Type.FORWARD_PORT));
+		issues.add(newPortedIssue("Enhancement 2", "4", null, "enhancement-2-url", Type.BACK_PORT));
+		given(this.service.getIssuesForMilestone(23, REPO)).willReturn(issues);
+		assertChangelog("23").content().isEqualTo(from("output-with-ported-issues-without-a-body"));
+	}
+
 	@Test
 	void generateWhenHasExcludedContributors() throws Exception {
 		User contributor1 = createUser("contributor1");

src/test/resources/io/spring/githubchangeloggenerator/output-with-ported-issues-without-a-body

@@ -0,0 +1,4 @@
+## :star: New Features
+
+- Enhancement 1 [#2](enhancement-1-url)
+- Enhancement 2 [#4](enhancement-2-url)