Support getting repository from project card

Closes #1097

Author: JLLeitschuh

src/main/java/org/kohsuke/github/GHIssue.java

@@ -79,6 +79,15 @@ GHIssue wrap(GHRepository owner) {
         return this;
     }
 
+    String getRepositoryUrlPath() {
+        String url = getUrl().toString();
+        int index = url.indexOf("/issues");
+        if (index == -1) {
+            index = url.indexOf("/pulls");
+        }
+        return url.substring(0, index);
+    }
+
     /**
      * Repository to which the issue belongs.
      *

src/main/java/org/kohsuke/github/GHProjectCard.java

@@ -115,7 +115,7 @@ public GHProjectColumn getColumn() throws IOException {
     }
 
     /**
-     * Gets content.
+     * Gets content. May be a {@link GHPullRequest} or a {@link GHIssue}.
      *
      * @return the content
      * @throws IOException
@@ -125,11 +125,16 @@ public GHIssue getContent() throws IOException {
         if (StringUtils.isEmpty(content_url))
             return null;
         try {
+            GHIssue issue;
             if (content_url.contains("/pulls")) {
-                return root().createRequest().withUrlPath(getContentUrl().getPath()).fetch(GHPullRequest.class);
+                issue = root().createRequest().withUrlPath(getContentUrl().getPath()).fetch(GHPullRequest.class);
             } else {
-                return root().createRequest().withUrlPath(getContentUrl().getPath()).fetch(GHIssue.class);
+                issue = root().createRequest().withUrlPath(getContentUrl().getPath()).fetch(GHIssue.class);
             }
+            GHRepository repository =
+                root().createRequest().withUrlPath(issue.getRepositoryUrlPath()).fetch(GHRepository.class);
+            issue.wrap(repository);
+            return issue;
         } catch (FileNotFoundException e) {
             return null;
         }

src/test/java/org/kohsuke/github/GHProjectCardTest.java

@@ -55,6 +55,8 @@ public void testCreateCardFromIssue() throws IOException {
             GHIssue issue = repo.createIssue("new-issue").body("With body").create();
             GHProjectCard card = column.createCard(issue);
             assertThat(card.getContentUrl(), equalTo(issue.getUrl()));
+            assertThat(card.getContent(), notNullValue());
+            assertThat(card.getContent().getRepository(), notNullValue());
         } finally {
             repo.delete();
         }