Add the issue to default column when adding to a project

models/issues/issue_project.go

 	return issuesMap, nil
 }
 
-// ChangeProjectAssign changes the project associated with an issue
-func ChangeProjectAssign(ctx context.Context, issue *Issue, doer *user_model.User, newProjectID int64) error {
-	ctx, committer, err := db.TxContext(ctx)
-	if err != nil {
-		return err
-	}
-	defer committer.Close()
-
-	if err := addUpdateIssueProject(ctx, issue, doer, newProjectID); err != nil {
-		return err
-	}
-
-	return committer.Commit()
+// ChangeProjectAssign changes the project associated with an issue, if newProjectID is 0, the issue is removed from the project
+func ChangeProjectAssign(ctx context.Context, issue *Issue, doer *user_model.User, newProjectID, newColumnID int64) error {
+	return db.WithTx(ctx, func(ctx context.Context) error {
+		return addUpdateIssueProject(ctx, issue, doer, newProjectID, newColumnID)
+	})
 }
 
-func addUpdateIssueProject(ctx context.Context, issue *Issue, doer *user_model.User, newProjectID int64) error {
+// addUpdateIssueProject adds or updates the project the default column associated with an issue
+// If newProjectID is 0, the issue is removed from the project
+func addUpdateIssueProject(ctx context.Context, issue *Issue, doer *user_model.User, newProjectID, newColumnID int64) error {
 	oldProjectID := issue.projectID(ctx)
 
 	if err := issue.LoadRepo(ctx); err != nil {
 			return err
 		}
 	}
+	if newProjectID == 0 || newColumnID == 0 {
+		return nil
+	}
+
+	var maxSorting int64
+	if _, err := db.GetEngine(ctx).Select("Max(sorting)").Table("project_issue").
+		Where("project_id=?", newProjectID).
+		And("project_board_id=?", newColumnID).
+		Get(&maxSorting); err != nil {
+		return err
+	}
+	if maxSorting > 0 {
+		maxSorting++
+	}
 
 	return db.Insert(ctx, &project_model.ProjectIssue{
-		IssueID:   issue.ID,
-		ProjectID: newProjectID,
+		IssueID:        issue.ID,
+		ProjectID:      newProjectID,
+		ProjectBoardID: newColumnID,
+		Sorting:        maxSorting,
 	})
 }

models/project/board.go

 		return fmt.Errorf("deleteBoardByID: cannot delete default board")
 	}
 
-	if err = board.removeIssues(ctx); err != nil {
+	// move all issues to the default column
+	project, err := GetProjectByID(ctx, board.ProjectID)
+	if err != nil {
+		return err
+	}
+	defaultBoard, err := project.GetDefaultBoard(ctx)
+	if err != nil {
+		return err
+	}
+
+	if err = board.moveIssuesToDefault(ctx, defaultBoard.ID); err != nil {
 		return err
 	}
 
 	return boards, nil
 }
 
-// getDefaultBoard return default board and ensure only one exists
-func (p *Project) getDefaultBoard(ctx context.Context) (*Board, error) {
+// GetDefaultBoard return default board and ensure only one exists
+func (p *Project) GetDefaultBoard(ctx context.Context) (*Board, error) {
 	var board Board
 	has, err := db.GetEngine(ctx).
 		Where("project_id=? AND `default` = ?", p.ID, true).

models/project/issue.go

 	IssueID   int64 `xorm:"INDEX"`
 	ProjectID int64 `xorm:"INDEX"`
 
-	// If 0, then it has not been added to a specific board in the project
+	// If this should not be zero from 1.22. If it's zero, it will not be displayed on UI and maybe result in errors.
 	ProjectBoardID int64 `xorm:"INDEX"`
 
 	// the sorting order on the board
 	})
 }
 
-func (b *Board) removeIssues(ctx context.Context) error {
-	_, err := db.GetEngine(ctx).Exec("UPDATE `project_issue` SET project_board_id = 0 WHERE project_board_id = ? ", b.ID)
+func (b *Board) moveIssuesToDefault(ctx context.Context, defaultBoardID int64) error {
+	_, err := db.GetEngine(ctx).Exec("UPDATE `project_issue` SET project_board_id = ? WHERE project_board_id = ? ", defaultBoardID, b.ID)
 	return err
 }
 

routers/web/org/projects.go

 	}
 
 	projectID := ctx.FormInt64("id")
+	var dstColumnID int64
+	if projectID > 0 {
+		dstProject, err := project_model.GetProjectByID(ctx, projectID)
+		if err != nil {
+			ctx.ServerError("GetProjectByID", err)
+			return
+		}
+		dstDefaultColumn, err := dstProject.GetDefaultBoard(ctx)
+		if err != nil {
+			ctx.ServerError("GetDefaultBoard", err)
+			return
+		}
+		dstColumnID = dstDefaultColumn.ID
+	}
+
 	for _, issue := range issues {
 		if issue.Project != nil {
 			if issue.Project.ID == projectID {
 			}
 		}
 
-		if err := issues_model.ChangeProjectAssign(ctx, issue, ctx.Doer, projectID); err != nil {
+		if err := issues_model.ChangeProjectAssign(ctx, issue, ctx.Doer, projectID, dstColumnID); err != nil {
 			ctx.ServerError("ChangeProjectAssign", err)
 			return
 		}

routers/web/repo/projects.go

 	}
 
 	projectID := ctx.FormInt64("id")
+	var dstColumnID int64
+	if projectID > 0 {
+		dstProject, err := project_model.GetProjectByID(ctx, projectID)
+		if err != nil {
+			ctx.ServerError("GetProjectByID", err)
+			return
+		}
+		dstDefaultColumn, err := dstProject.GetDefaultBoard(ctx)
+		if err != nil {
+			ctx.ServerError("GetDefaultBoard", err)
+			return
+		}
+		dstColumnID = dstDefaultColumn.ID
+	}
+
 	for _, issue := range issues {
 		if issue.Project != nil {
 			if issue.Project.ID == projectID {
 			}
 		}
 
-		if err := issues_model.ChangeProjectAssign(ctx, issue, ctx.Doer, projectID); err != nil {
+		if err := issues_model.ChangeProjectAssign(ctx, issue, ctx.Doer, projectID, dstColumnID); err != nil {
 			ctx.ServerError("ChangeProjectAssign", err)
 			return
 		}

routers/web/repo/pull.go

 	git_model "code.gitea.io/gitea/models/git"
 	issues_model "code.gitea.io/gitea/models/issues"
 	access_model "code.gitea.io/gitea/models/perm/access"
+	project_model "code.gitea.io/gitea/models/project"
 	pull_model "code.gitea.io/gitea/models/pull"
 	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/models/unit"
 
 	if projectID > 0 {
 		if !ctx.Repo.CanWrite(unit.TypeProjects) {
-			ctx.Error(http.StatusBadRequest, "user hasn't the permission to write to projects")
+			log.Error("user hasn't the permission to write to projects")
 			return
 		}
-		if err := issues_model.ChangeProjectAssign(ctx, pullIssue, ctx.Doer, projectID); err != nil {
+		dstProject, err := project_model.GetProjectByID(ctx, projectID)
+		if err != nil {
+			ctx.ServerError("GetProjectByID", err)
+			return
+		}
+		dstDefaultColumn, err := dstProject.GetDefaultBoard(ctx)
+		if err != nil {
+			ctx.ServerError("GetDefaultBoard", err)
+			return
+		}
+		if err := issues_model.ChangeProjectAssign(ctx, pullIssue, ctx.Doer, projectID, dstDefaultColumn.ID); err != nil {
 			ctx.ServerError("ChangeProjectAssign", err)
 			return
 		}

services/issue/issue.go

 			}
 		}
 		if projectID > 0 {
-			if err := issues_model.ChangeProjectAssign(ctx, issue, issue.Poster, projectID); err != nil {
+			project, err := project_model.GetProjectByID(ctx, projectID)
+			if err != nil {
+				return err
+			}
+			defaultBoard, err := project.GetDefaultBoard(ctx)
+			if err != nil {
+				return err
+			}
+			if err := issues_model.ChangeProjectAssign(ctx, issue, issue.Poster, projectID, defaultBoard.ID); err != nil {
 				return err
 			}
 		}