Support for revert pull request

2025-10-29 09:36:16 +01:00 · 2025-08-13 08:06:05 +09:00
9 changed files with 219 additions and 74 deletions
--- a/src/main/resources/update/gitbucket-core_4.0.xml
+++ b/src/main/resources/update/gitbucket-core_4.0.xml
@@ -237,7 +237,7 @@
  <addForeignKeyConstraint constraintName="IDX_ISSUE_ID_FK1" baseTableName="ISSUE_ID" baseColumnNames="USER_NAME, REPOSITORY_NAME" referencedTableName="REPOSITORY" referencedColumnNames="USER_NAME, REPOSITORY_NAME"/>

  <!--================================================================================================-->
-  <!-- ISSUE_ID -->
+  <!-- ISSUE_LABEL -->
  <!--================================================================================================-->
  <createTable tableName="ISSUE_LABEL">
    <column name="USER_NAME" type="varchar(100)" nullable="false"/>
--- a/src/main/resources/update/gitbucket-core_4.44.xml
+++ b/src/main/resources/update/gitbucket-core_4.44.xml
@@ -29,4 +29,12 @@
  <addPrimaryKey constraintName="IDX_PROTECTED_BRANCH_RESTRICTION_PK" tableName="PROTECTED_BRANCH_RESTRICTION" columnNames="USER_NAME, REPOSITORY_NAME, BRANCH, ALLOWED_USER"/>
  <addForeignKeyConstraint constraintName="IDX_PROTECTED_BRANCH_RESTRICTION_FK0" baseTableName="PROTECTED_BRANCH_RESTRICTION" baseColumnNames="USER_NAME, REPOSITORY_NAME, BRANCH" referencedTableName="PROTECTED_BRANCH" referencedColumnNames="USER_NAME, REPOSITORY_NAME, BRANCH" onDelete="CASCADE" onUpdate="CASCADE"/>
  <addForeignKeyConstraint constraintName="IDX_PROTECTED_BRANCH_RESTRICTION_FK1" baseTableName="PROTECTED_BRANCH_RESTRICTION" baseColumnNames="ALLOWED_USER" referencedTableName="ACCOUNT" referencedColumnNames="USER_NAME"/>
+
+  <!--================================================================================================-->
+  <!-- PULL_REQUEST -->
+  <!--================================================================================================-->
+  <addColumn tableName="PULL_REQUEST">
+    <column name="MERGED_COMMIT_IDS" type="text" nullable="true"/>
+  </addColumn>
+
 </changeSet>
--- a/src/main/scala/gitbucket/core/controller/PullRequestsController.scala
+++ b/src/main/scala/gitbucket/core/controller/PullRequestsController.scala
@@ -13,8 +13,10 @@ import gitbucket.core.util.Implicits.*
 import gitbucket.core.util.*
 import org.scalatra.forms.*
 import org.eclipse.jgit.api.Git
+import org.eclipse.jgit.revwalk.RevWalk
 import org.scalatra.BadRequest

+import java.nio.file.Files
 import scala.util.Using

 class PullRequestsController
@@ -247,41 +249,43 @@ trait PullRequestsControllerBase extends ControllerBase {
  })

  get("/:owner/:repository/pull/:id/delete_branch")(readableUsersOnly { baseRepository =>
-    (for {
-      issueId <- params("id").toIntOpt
-      loginAccount <- context.loginAccount
-      case (issue, pullreq) <- getPullRequest(baseRepository.owner, baseRepository.name, issueId)
-      owner = pullreq.requestUserName
-      name = pullreq.requestRepositoryName
-      if hasDeveloperRole(owner, name, context.loginAccount)
-    } yield {
-      val repository = getRepository(owner, name).get
-      val branchProtection = getProtectedBranchInfo(owner, name, pullreq.requestBranch)
-      if (branchProtection.enabled) {
-        flash.update("error", s"branch ${pullreq.requestBranch} is protected.")
-      } else {
-        if (repository.repository.defaultBranch != pullreq.requestBranch) {
-          val userName = context.loginAccount.get.userName
-          Using.resource(Git.open(getRepositoryDir(repository.owner, repository.name))) { git =>
-            git.branchDelete().setForce(true).setBranchNames(pullreq.requestBranch).call()
-            val deleteBranchInfo = DeleteBranchInfo(repository.owner, repository.name, userName, pullreq.requestBranch)
-            recordActivity(deleteBranchInfo)
-          }
-          createComment(
-            baseRepository.owner,
-            baseRepository.name,
-            userName,
-            issueId,
-            pullreq.requestBranch,
-            "delete_branch"
-          )
+    context.withLoginAccount { _ =>
+      (for {
+        issueId <- params("id").toIntOpt
+        case (issue, pullreq) <- getPullRequest(baseRepository.owner, baseRepository.name, issueId)
+        owner = pullreq.requestUserName
+        name = pullreq.requestRepositoryName
+        if hasDeveloperRole(owner, name, context.loginAccount)
+      } yield {
+        val repository = getRepository(owner, name).get
+        val branchProtection = getProtectedBranchInfo(owner, name, pullreq.requestBranch)
+        if (branchProtection.enabled) {
+          flash.update("error", s"branch ${pullreq.requestBranch} is protected.")
        } else {
-          flash.update("error", s"""Can't delete the default branch "${pullreq.requestBranch}".""")
+          if (repository.repository.defaultBranch != pullreq.requestBranch) {
+            val userName = context.loginAccount.get.userName
+            Using.resource(Git.open(getRepositoryDir(repository.owner, repository.name))) { git =>
+              git.branchDelete().setForce(true).setBranchNames(pullreq.requestBranch).call()
+              val deleteBranchInfo =
+                DeleteBranchInfo(repository.owner, repository.name, userName, pullreq.requestBranch)
+              recordActivity(deleteBranchInfo)
+            }
+            createComment(
+              baseRepository.owner,
+              baseRepository.name,
+              userName,
+              issueId,
+              pullreq.requestBranch,
+              "delete_branch"
+            )
+          } else {
+            flash.update("error", s"""Can't delete the default branch "${pullreq.requestBranch}".""")
+          }
        }
-      }

-      redirect(s"/${baseRepository.owner}/${baseRepository.name}/pull/${issueId}")
-    }) getOrElse NotFound()
+        redirect(s"/${baseRepository.owner}/${baseRepository.name}/pull/${issueId}")
+      }) getOrElse NotFound()
+    }
  })

  post("/:owner/:repository/pull/:id/update_branch")(readableUsersOnly { baseRepository =>
@@ -361,8 +365,11 @@ trait PullRequestsControllerBase extends ControllerBase {
          form.isDraft,
          context.settings
        ) match {
-          case Right(objectId) => redirect(s"/${repository.owner}/${repository.name}/pull/$issueId")
-          case Left(message)   => Some(BadRequest(message))
+          case Right(result) =>
+            updateMergedCommitIds(repository.owner, repository.name, issueId, result.mergedCommitId)
+            redirect(s"/${repository.owner}/${repository.name}/pull/$issueId")
+          case Left(message) =>
+            Some(BadRequest(message))
        }
      } getOrElse NotFound()
    }
@@ -722,6 +729,107 @@ trait PullRequestsControllerBase extends ControllerBase {
    )
  }

+  post("/:owner/:repository/pull/:id/revert")(writableUsersOnly { repository =>
+    context.withLoginAccount { loginAccount =>
+      (for {
+        issueId <- params.get("id").map(_.toInt)
+        (issue, pullreq) <- getPullRequest(repository.owner, repository.name, issueId) if issue.closed
+      } yield {
+        val baseBranch = pullreq.branch
+        val revertBranch = s"revert-pr-$issueId-${System.currentTimeMillis()}"
+
+        Using.resource(Git.open(getRepositoryDir(repository.owner, repository.name))) { git =>
+          try {
+            // Create a new branch from base
+            JGitUtil.createBranch(git, baseBranch, revertBranch)
+            // TODO Call webhook ???
+
+            val tempDir = Files.createTempDirectory("jgit-revert-")
+            val revertCommitName =
+              try {
+                // Clone bare repository
+                Using.resource(
+                  Git.cloneRepository
+                    .setURI(getRepositoryDir(repository.owner, repository.name).getAbsolutePath)
+                    .setDirectory(tempDir.toFile)
+                    .setBranch(revertBranch)
+                    .setBare(false)
+                    .setNoCheckout(false)
+                    .call()
+                ) { git =>
+                  // Get commit Ids to be reverted
+                  val commitsToRevert = Using.resource(new RevWalk(git.getRepository)) { revWalk =>
+                    pullreq.mergedCommitIds
+                      .map(
+                        _.split(",")
+                          .map { mergedCommitId =>
+                            revWalk.parseCommit(git.getRepository.resolve(mergedCommitId))
+                          }
+                          .toSeq
+                          .reverse
+                      )
+                      .getOrElse(Nil)
+                  }
+
+                  // revert
+                  var revert = git.revert
+                  commitsToRevert.foreach { id =>
+                    revert = revert.include(id)
+                  }
+                  val newCommit = revert.call()
+                  if (newCommit != null) {
+                    System.out.println("Reverted commit created: " + newCommit.getName)
+                    git.push.call()
+                    Some(newCommit.getName)
+                  } else {
+                    System.out.println("Revert resulted in conflicts.")
+                    None
+                  }
+                }
+              } finally {
+                FileUtil.deleteRecursively(tempDir.toFile)
+              }
+
+            revertCommitName match {
+              case Some(revertCommitName) =>
+                val newIssueId = insertIssue(
+                  owner = repository.owner,
+                  repository = repository.name,
+                  loginUser = loginAccount.userName,
+                  title = s"Revert #${issueId}",
+                  content = Some(s"Revert #${issueId}"),
+                  milestoneId = None,
+                  priorityId = None,
+                  isPullRequest = true
+                )
+                createPullRequest(
+                  originRepository = repository,
+                  issueId = newIssueId,
+                  originBranch = baseBranch,
+                  requestUserName = repository.owner,
+                  requestRepositoryName = repository.name,
+                  requestBranch = revertBranch,
+                  commitIdFrom = baseBranch,
+                  commitIdTo = revertCommitName,
+                  isDraft = false,
+                  loginAccount = loginAccount,
+                  settings = context.settings
+                )
+                redirect(s"/${repository.owner}/${repository.name}/pull/$newIssueId")
+
+              case None =>
+                BadRequest("Failed to create revert commit.")
+            }
+          } catch {
+            case ex: Exception =>
+              ex.printStackTrace()
+              BadRequest(s"Revert failed: ${ex.getMessage}")
+          }
+        }
+      }) getOrElse NotFound()
+    }
+  })
+
  /**
   * Tests whether an logged-in user can manage pull requests.
   */
@@ -740,5 +848,4 @@ trait PullRequestsControllerBase extends ControllerBase {
      case "DISABLE" => false
    }
  }
-
 }
--- a/src/main/scala/gitbucket/core/model/PullRequest.scala
+++ b/src/main/scala/gitbucket/core/model/PullRequest.scala
@@ -13,6 +13,7 @@ trait PullRequestComponent extends TemplateComponent { self: Profile =>
    val commitIdFrom = column[String]("COMMIT_ID_FROM")
    val commitIdTo = column[String]("COMMIT_ID_TO")
    val isDraft = column[Boolean]("IS_DRAFT")
+    val mergedCommitIds = column[String]("MERGED_COMMIT_IDS")
    def * =
      (
        userName,
@@ -24,12 +25,13 @@ trait PullRequestComponent extends TemplateComponent { self: Profile =>
        requestBranch,
        commitIdFrom,
        commitIdTo,
-        isDraft
+        isDraft,
+        mergedCommitIds.?
      ).mapTo[PullRequest]

-    def byPrimaryKey(userName: String, repositoryName: String, issueId: Int) =
+    def byPrimaryKey(userName: String, repositoryName: String, issueId: Int): Rep[Boolean] =
      byIssue(userName, repositoryName, issueId)
-    def byPrimaryKey(userName: Rep[String], repositoryName: Rep[String], issueId: Rep[Int]) =
+    def byPrimaryKey(userName: Rep[String], repositoryName: Rep[String], issueId: Rep[Int]): Rep[Boolean] =
      byIssue(userName, repositoryName, issueId)
  }
 }
@@ -44,5 +46,6 @@ case class PullRequest(
  requestBranch: String,
  commitIdFrom: String,
  commitIdTo: String,
-  isDraft: Boolean
+  isDraft: Boolean,
+  mergedCommitIds: Option[String]
 )
--- a/src/main/scala/gitbucket/core/service/MergeService.scala
+++ b/src/main/scala/gitbucket/core/service/MergeService.scala
@@ -7,7 +7,7 @@ import gitbucket.core.plugin.{PluginRegistry, ReceiveHook}
 import gitbucket.core.service.RepositoryService.RepositoryInfo
 import gitbucket.core.util.Directory._
 import gitbucket.core.util.{JGitUtil, LockUtil}
-import gitbucket.core.model.Profile.profile.blockingApi._
+import gitbucket.core.model.Profile.profile.blockingApi.*
 import gitbucket.core.model.activity.{CloseIssueInfo, MergeInfo, PushInfo}
 import gitbucket.core.service.SystemSettingsService.SystemSettings
 import gitbucket.core.service.WebHookService.WebHookPushPayload
@@ -19,14 +19,14 @@ import org.eclipse.jgit.errors.NoMergeBaseException
 import org.eclipse.jgit.lib.{CommitBuilder, ObjectId, PersonIdent, Repository}
 import org.eclipse.jgit.revwalk.{RevCommit, RevWalk}

-import scala.jdk.CollectionConverters._
+import scala.jdk.CollectionConverters.*
 import scala.util.Using

 trait MergeService {
  self: AccountService & ActivityService & IssuesService & RepositoryService & PullRequestService &
    WebHookPullRequestService & WebHookService =>

-  import MergeService._
+  import MergeService.*

  /**
   * Checks whether conflict will be caused in merging within pull request.
@@ -61,15 +61,16 @@ trait MergeService {
    repository: RepositoryInfo,
    branch: String,
    issueId: Int,
+    commits: Seq[RevCommit],
    message: String,
    loginAccount: Account,
    settings: SystemSettings
-  )(implicit s: Session, c: JsonFormat.Context): ObjectId = {
+  )(implicit s: Session, c: JsonFormat.Context): MergeResult = {
    val beforeCommitId = git.getRepository.resolve(s"refs/heads/${branch}")
-    val afterCommitId = new MergeCacheInfo(git, repository.owner, repository.name, branch, issueId, getReceiveHooks())
-      .merge(message, new PersonIdent(loginAccount.fullName, loginAccount.mailAddress), loginAccount.userName)
-    callWebHook(git, repository, branch, beforeCommitId, afterCommitId, loginAccount, settings)
-    afterCommitId
+    val mergeResult = new MergeCacheInfo(git, repository.owner, repository.name, branch, issueId, getReceiveHooks())
+      .merge(message, new PersonIdent(loginAccount.fullName, loginAccount.mailAddress), loginAccount.userName, commits)
+    callWebHook(git, repository, branch, beforeCommitId, mergeResult.newCommitId, loginAccount, settings)
+    mergeResult
  }

  /** rebase to the head of the pull request branch */
@@ -81,13 +82,13 @@ trait MergeService {
    commits: Seq[RevCommit],
    loginAccount: Account,
    settings: SystemSettings
-  )(implicit s: Session, c: JsonFormat.Context): ObjectId = {
+  )(implicit s: Session, c: JsonFormat.Context): MergeResult = {
    val beforeCommitId = git.getRepository.resolve(s"refs/heads/${branch}")
-    val afterCommitId =
+    val mergeResult =
      new MergeCacheInfo(git, repository.owner, repository.name, branch, issueId, getReceiveHooks())
        .rebase(new PersonIdent(loginAccount.fullName, loginAccount.mailAddress), loginAccount.userName, commits)
-    callWebHook(git, repository, branch, beforeCommitId, afterCommitId, loginAccount, settings)
-    afterCommitId
+    callWebHook(git, repository, branch, beforeCommitId, mergeResult.newCommitId, loginAccount, settings)
+    mergeResult
  }

  /** squash commits in the pull request and append it */
@@ -99,13 +100,13 @@ trait MergeService {
    message: String,
    loginAccount: Account,
    settings: SystemSettings
-  )(implicit s: Session, c: JsonFormat.Context): ObjectId = {
+  )(implicit s: Session, c: JsonFormat.Context): MergeResult = {
    val beforeCommitId = git.getRepository.resolve(s"refs/heads/${branch}")
-    val afterCommitId =
+    val mergeResult =
      new MergeCacheInfo(git, repository.owner, repository.name, branch, issueId, getReceiveHooks())
        .squash(message, new PersonIdent(loginAccount.fullName, loginAccount.mailAddress), loginAccount.userName)
-    callWebHook(git, repository, branch, beforeCommitId, afterCommitId, loginAccount, settings)
-    afterCommitId
+    callWebHook(git, repository, branch, beforeCommitId, mergeResult.newCommitId, loginAccount, settings)
+    mergeResult
  }

  private def callWebHook(
@@ -337,7 +338,7 @@ trait MergeService {
    strategy: String,
    isDraft: Boolean,
    settings: SystemSettings
-  )(implicit s: Session, c: JsonFormat.Context, context: Context): Either[String, ObjectId] = {
+  )(implicit s: Session, c: JsonFormat.Context, context: Context): Either[String, MergeResult] = {
    if (!isDraft) {
      if (repository.repository.options.mergeOptions.split(",").contains(strategy)) {
        LockUtil.lock(s"${repository.owner}/${repository.name}") {
@@ -493,7 +494,7 @@ trait MergeService {
    commits: Seq[Seq[CommitInfo]],
    receiveHooks: Seq[ReceiveHook],
    settings: SystemSettings
-  )(implicit s: Session, c: JsonFormat.Context): Option[ObjectId] = {
+  )(implicit s: Session, c: JsonFormat.Context): Option[MergeResult] = {
    val revCommits = Using
      .resource(new RevWalk(git.getRepository)) { revWalk =>
        commits.flatten.map { commit =>
@@ -510,6 +511,7 @@ trait MergeService {
            repository,
            pullRequest.branch,
            issue.issueId,
+            revCommits,
            s"Merge pull request #${issue.issueId} from ${pullRequest.requestUserName}/${pullRequest.requestBranch}\n\n" + message,
            loginAccount,
            settings
@@ -600,13 +602,13 @@ object MergeService {
    private val mergedBranchName = s"refs/pull/${issueId}/merge"
    private val conflictedBranchName = s"refs/pull/${issueId}/conflict"

-    lazy val mergeBaseTip = git.getRepository.resolve(s"refs/heads/${branch}")
-    lazy val mergeTip = git.getRepository.resolve(s"refs/pull/${issueId}/head")
+    lazy val mergeBaseTip: ObjectId = git.getRepository.resolve(s"refs/heads/${branch}")
+    lazy val mergeTip: ObjectId = git.getRepository.resolve(s"refs/pull/${issueId}/head")

    def checkConflictCache(): Option[Option[String]] = {
      Option(git.getRepository.resolve(mergedBranchName))
        .flatMap { merged =>
-          if (parseCommit(merged).getParents().toSet == Set(mergeBaseTip, mergeTip)) {
+          if (parseCommit(merged).getParents.toSet == Set(mergeBaseTip, mergeTip)) {
            // merged branch exists
            Some(None)
          } else {
@@ -615,7 +617,7 @@ object MergeService {
        }
        .orElse(Option(git.getRepository.resolve(conflictedBranchName)).flatMap { conflicted =>
          val commit = parseCommit(conflicted)
-          if (commit.getParents().toSet == Set(mergeBaseTip, mergeTip)) {
+          if (commit.getParents.toSet == Set(mergeBaseTip, mergeTip)) {
            // conflict branch exists
            Some(Some(commit.getFullMessage))
          } else {
@@ -651,14 +653,16 @@ object MergeService {
        None
      } else {
        val message = createConflictMessage(mergeTip, mergeBaseTip, merger)
-        _updateBranch(mergeTipCommit.getTree().getId(), message, conflictedBranchName)
+        _updateBranch(mergeTipCommit.getTree.getId, message, conflictedBranchName)
        git.branchDelete().setForce(true).setBranchNames(mergedBranchName).call()
        Some(message)
      }
    }

    // update branch from cache
-    def merge(message: String, committer: PersonIdent, pusher: String)(implicit s: Session): ObjectId = {
+    def merge(message: String, committer: PersonIdent, pusher: String, commits: Seq[RevCommit])(implicit
+      s: Session
+    ): MergeResult = {
      if (checkConflict().isDefined) {
        throw new RuntimeException("This pull request can't merge automatically.")
      }
@@ -666,7 +670,7 @@ object MergeService {
        throw new RuntimeException(s"Not found branch ${mergedBranchName}")
      })
      // creates merge commit
-      val mergeCommitId = createMergeCommit(mergeResultCommit.getTree().getId(), committer, message)
+      val mergeCommitId = createMergeCommit(mergeResultCommit.getTree.getId, committer, message)

      val refName = s"refs/heads/${branch}"
      val currentObjectId = git.getRepository.resolve(refName)
@@ -690,10 +694,10 @@ object MergeService {
        hook.postReceive(userName, repositoryName, receivePack, receiveCommand, committer.getName, true)
      }

-      objectId
+      MergeResult(objectId, commits.map(_.name()))
    }

-    def rebase(committer: PersonIdent, pusher: String, commits: Seq[RevCommit])(implicit s: Session): ObjectId = {
+    def rebase(committer: PersonIdent, pusher: String, commits: Seq[RevCommit])(implicit s: Session): MergeResult = {
      if (checkConflict().isDefined) {
        throw new RuntimeException("This pull request can't merge automatically.")
      }
@@ -713,11 +717,13 @@ object MergeService {

      val mergeBaseTipCommit = Using.resource(new RevWalk(git.getRepository))(_.parseCommit(mergeBaseTip))
      var previousId = mergeBaseTipCommit.getId
+      val mergedCommitIds = Seq.newBuilder[String]

      Using.resource(git.getRepository.newObjectInserter) { inserter =>
        commits.foreach { commit =>
          val nextCommit = _cloneCommit(commit, previousId, mergeBaseTipCommit.getId)
          previousId = inserter.insert(nextCommit)
+          mergedCommitIds += previousId.name()
        }
        inserter.flush()
      }
@@ -745,10 +751,10 @@ object MergeService {
        hook.postReceive(userName, repositoryName, receivePack, receiveCommand, committer.getName, true)
      }

-      objectId
+      MergeResult(objectId, mergedCommitIds.result())
    }

-    def squash(message: String, committer: PersonIdent, pusher: String)(implicit s: Session): ObjectId = {
+    def squash(message: String, committer: PersonIdent, pusher: String)(implicit s: Session): MergeResult = {
      if (checkConflict().isDefined) {
        throw new RuntimeException("This pull request can't merge automatically.")
      }
@@ -804,7 +810,7 @@ object MergeService {
        hook.postReceive(userName, repositoryName, receivePack, receiveCommand, committer.getName, true)
      }

-      objectId
+      MergeResult(objectId, Seq(newCommitId.name()))
    }

    // return treeId
@@ -823,4 +829,5 @@ object MergeService {
      mergeResults.asScala.map { case (key, _) => "- `" + key + "`\n" }.mkString
  }

+  case class MergeResult(newCommitId: ObjectId, mergedCommitId: Seq[String])
 }
--- a/src/main/scala/gitbucket/core/service/PullRequestService.scala
+++ b/src/main/scala/gitbucket/core/service/PullRequestService.scala
@@ -63,6 +63,15 @@ trait PullRequestService {
      .update((baseBranch, commitIdTo))
  }

+  def updateMergedCommitIds(owner: String, repository: String, issueId: Int, mergedCommitIds: Seq[String])(implicit
+    s: Session
+  ): Unit = {
+    PullRequests
+      .filter(_.byPrimaryKey(owner, repository, issueId))
+      .map(pr => pr.mergedCommitIds)
+      .update(mergedCommitIds.mkString(","))
+  }
+
  def getPullRequestCountGroupByUser(closed: Boolean, owner: Option[String], repository: Option[String])(implicit
    s: Session
  ): List[PullRequestCount] =
@@ -126,7 +135,8 @@ trait PullRequestService {
        requestBranch,
        commitIdFrom,
        commitIdTo,
-        isDraft
+        isDraft,
+        None
      )

      // fetch requested branch
@@ -408,11 +418,10 @@ trait PullRequestService {
        .find(x => x.oldPath == file)
        .map { diff =>
          (diff.oldContent, diff.newContent) match {
-            case (Some(oldContent), Some(newContent)) => {
+            case (Some(oldContent), Some(newContent)) =>
              val oldLines = convertLineSeparator(oldContent, "LF").split("\n")
              val newLines = convertLineSeparator(newContent, "LF").split("\n")
              file -> Option(DiffUtils.diff(oldLines.toList.asJava, newLines.toList.asJava))
-            }
            case _ =>
              file -> None
          }
--- a/src/main/twirl/gitbucket/core/pulls/conversation.scala.html
+++ b/src/main/twirl/gitbucket/core/pulls/conversation.scala.html
@@ -81,4 +81,13 @@
    });
  });
  </script>
+  @if(issue.closed && pullreq.mergedCommitIds.isDefined){
+    <div class="issue-comment-box" style="margin-bottom: 20px;">
+      <div style="padding: 10px;">
+        <form method="post" action="@helpers.url(repository)/pull/@issue.issueId/revert" style="display:inline;">
+          <button type="submit" class="btn btn-warning pull-right" style="margin-left: 10px;">Revert</button>
+        </form>
+      </div>
+    </div>
+  }
 }
--- a/src/test/scala/gitbucket/core/api/ApiSpecModels.scala
+++ b/src/test/scala/gitbucket/core/api/ApiSpecModels.scala
@@ -154,7 +154,8 @@ object ApiSpecModels {
    requestBranch = "new-topic",
    commitIdFrom = sha1,
    commitIdTo = sha1,
-    isDraft = true
+    isDraft = true,
+    mergedCommitIds = None
  )

  val commitComment: CommitComment = CommitComment(
--- a/src/test/scala/gitbucket/core/service/MergeServiceSpec.scala
+++ b/src/test/scala/gitbucket/core/service/MergeServiceSpec.scala
@@ -171,6 +171,7 @@ class MergeServiceSpec extends AnyFunSpec with ServiceSpecBase {
              repository,
              branch,
              issueId,
+              Seq(git.getRepository.parseCommit(commitId)),
              "merged",
              context.loginAccount.get,
              context.settings