Fix getting merge requests originating from forked and deleted projects

See timols/java-gitlab-api#403 for the same fix
upstream.

Author: cpfeiffer

src/main/java/com/dkaedv/glghproxy/GitlabAPIExt.java

@@ -0,0 +1,56 @@
+package com.dkaedv.glghproxy;
+
+import java.io.IOException;
+import java.io.Serializable;
+import java.io.UnsupportedEncodingException;
+import java.net.URLEncoder;
+import java.util.Arrays;
+import java.util.List;
+
+import org.gitlab.api.GitlabAPI;
+import org.gitlab.api.Pagination;
+import org.gitlab.api.models.GitlabCommit;
+import org.gitlab.api.models.GitlabMergeRequest;
+import org.gitlab.api.models.GitlabProject;
+
+/**
+ * Helper class for fixing bugs in GitlabAPI until they are fixed upstream.
+ */
+public class GitlabAPIExt {
+	private GitlabAPI api;
+
+	public GitlabAPIExt(GitlabAPI api) {
+		this.api = api;
+	}
+
+    public List<GitlabCommit> getCommits(GitlabMergeRequest mergeRequest) throws IOException {
+        return getCommits(mergeRequest, new Pagination());
+    }
+
+    public List<GitlabCommit> getCommits(GitlabMergeRequest mergeRequest, Pagination pagination) throws IOException {
+        Integer projectId = mergeRequest.getProjectId();
+
+        String tailUrl = GitlabProject.URL + "/" + sanitizeProjectId(projectId) +
+                GitlabMergeRequest.URL + "/" + mergeRequest.getIid() +
+                GitlabCommit.URL + pagination.toString();
+
+        GitlabCommit[] commits = api.retrieve().to(tailUrl, GitlabCommit[].class);
+        return Arrays.asList(commits);
+    }
+
+    private String sanitizeProjectId(Serializable projectId) {
+        return sanitizeId(projectId, "projectId");
+    }
+
+    private String sanitizeId(Serializable id, String parameterName) {
+        if (!(id instanceof String) && !(id instanceof Number)) {
+            throw new IllegalArgumentException(parameterName + " needs to be of type String or Number");
+        }
+
+        try {
+            return URLEncoder.encode(String.valueOf(id), "UTF-8");
+        } catch (UnsupportedEncodingException e) {
+            throw new RuntimeException((e));
+        }
+    }
+}

src/main/java/com/dkaedv/glghproxy/controller/ReposController.java

@@ -40,6 +40,7 @@
 import org.springframework.web.bind.annotation.ResponseStatus;
 
 import com.dkaedv.glghproxy.Constants;
+import com.dkaedv.glghproxy.GitlabAPIExt;
 import com.dkaedv.glghproxy.Utils;
 import com.dkaedv.glghproxy.converter.GitlabToGithubConverter;
 import com.dkaedv.glghproxy.githubentity.HookRequest;
@@ -167,7 +168,7 @@ public List<RepositoryCommit> getCommitsOnPullRequest(@PathVariable String names
 		repo = OwnerFixup.fixupRepo(repo, treatOrgaAsOwner);
 		GitlabAPI api = gitlab.connect(authorization);
 		GitlabMergeRequest mergeRequest = findMergeRequestByProjectAndIid(namespace, repo, id, api);
-		List<GitlabCommit> commits = api.getCommits(mergeRequest);
+		List<GitlabCommit> commits = new GitlabAPIExt(api).getCommits(mergeRequest);
 
 		return GitlabToGithubConverter.convertCommits(commits, env);
 	}