Fix GHFileNotFoundException when getting commits from PR found in search (#1779)

* Replace /issues/ with /pulls/ in sourced URL for Pull Requests.

Previously, when a pull request had been fetched, it lacked an
`owner`, and thus was following a specific codepath inside
`GHPullRequest.GetApiRoute` that was returning a URL that corresponded
to an `issue`. When that URL was then appended on for further queries,
say, with `/commits`, then Github would return a 404.

This fixes the issue by manipulating the URL manually and replacing
the wrong reference to `/issues/` with `/pulls/`.

* Add test for issue with List of Commits returning 404.

---------

Co-authored-by: Liam Newman <[email protected]>

Author: NlightNFotis

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

@@ -100,7 +100,12 @@ protected String getApiRoute() {
         if (owner == null) {
             // Issues returned from search to do not have an owner. Attempt to use url.
             final URL url = Objects.requireNonNull(getUrl(), "Missing instance URL!");
-            return StringUtils.prependIfMissing(url.toString().replace(root().getApiUrl(), ""), "/");
+            // The url sourced above is of the form '/repos/<owner>/<reponame>/issues/', which
+            // subsequently issues requests against the `/issues/` handler, causing a 404 when
+            // asking for, say, a list of commits associated with a PR. Replace the `/issues/`
+            // with `/pulls/` to avoid that.
+            return StringUtils.prependIfMissing(url.toString().replace(root().getApiUrl(), ""), "/")
+                    .replace("/issues/", "/pulls/");
         }
         return "/repos/" + owner.getOwnerName() + "/" + owner.getName() + "/pulls/" + number;
     }

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

@@ -178,6 +178,32 @@ public void pullRequestComment() throws Exception {
         assertThat(comments, contains(hasProperty("body", equalTo("Second comment"))));
     }
 
+    /**
+     * Get list of commits from searched PR.
+     *
+     * This would result in a wrong API URL used, resulting in a GHFileNotFoundException.
+     *
+     * For more details, please have a look at the bug description in https://github.com/hub4j/github-api/issues/1778.
+     *
+     * @throws Exception
+     *             the exception
+     */
+    @Test
+    public void getListOfCommits() throws Exception {
+        String name = "getListOfCommits";
+        GHPullRequestSearchBuilder builder = getRepository().searchPullRequests().isClosed();
+        Optional<GHPullRequest> firstPR = builder.list().toList().stream().findFirst();
+
+        try {
+            String val = firstPR.get().listCommits().toArray()[0].getApiUrl().toString();
+            assertThat(val, notNullValue());
+        } catch (GHFileNotFoundException e) {
+            if (e.getMessage().contains("/issues/")) {
+                fail("Issued a request against the wrong path");
+            }
+        }
+    }
+
     /**
      * Close pull request.
      *

src/test/resources/org/kohsuke/github/GHPullRequestTest/wiremock/getListOfCommits/__files/1-user.json

@@ -0,0 +1,34 @@
+{
+  "login": "NlightNFotis",
+  "id": 1859274,
+  "node_id": "MDQ6VXNlcjE4NTkyNzQ=",
+  "avatar_url": "https://avatars.githubusercontent.com/u/1859274?v=4",
+  "gravatar_id": "",
+  "url": "https://api.github.com/users/NlightNFotis",
+  "html_url": "https://github.com/NlightNFotis",
+  "followers_url": "https://api.github.com/users/NlightNFotis/followers",
+  "following_url": "https://api.github.com/users/NlightNFotis/following{/other_user}",
+  "gists_url": "https://api.github.com/users/NlightNFotis/gists{/gist_id}",
+  "starred_url": "https://api.github.com/users/NlightNFotis/starred{/owner}{/repo}",
+  "subscriptions_url": "https://api.github.com/users/NlightNFotis/subscriptions",
+  "organizations_url": "https://api.github.com/users/NlightNFotis/orgs",
+  "repos_url": "https://api.github.com/users/NlightNFotis/repos",
+  "events_url": "https://api.github.com/users/NlightNFotis/events{/privacy}",
+  "received_events_url": "https://api.github.com/users/NlightNFotis/received_events",
+  "type": "User",
+  "site_admin": false,
+  "name": "Fotis Koutoulakis",
+  "company": "@diffblue ",
+  "blog": "https://nlightnfotis.github.io",
+  "location": "Oxford, United Kingdom",
+  "email": "[email protected]",
+  "hireable": null,
+  "bio": "Interests in Mathematics, Computer Science, Biology and Economics.",
+  "twitter_username": "NlightNFotis",
+  "public_repos": 27,
+  "public_gists": 8,
+  "followers": 38,
+  "following": 51,
+  "created_at": "2012-06-17T17:34:11Z",
+  "updated_at": "2023-09-18T09:30:51Z"
+}