add active user check when adding a new collaborator via the api

Author: adelowo

routers/api/v1/repo/collaborators.go

@@ -5,6 +5,8 @@
 package repo
 
 import (
+	"errors"
+
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/context"
 
@@ -145,6 +147,11 @@ func AddCollaborator(ctx *context.APIContext, form api.AddCollaboratorOption) {
 		return
 	}
 
+	if !collaborator.IsActive {
+		ctx.Error(500, "InactiveCollaborator", errors.New("collaborator's account is inactive"))
+		return
+	}
+
 	if err := ctx.Repo.Repository.AddCollaborator(collaborator); err != nil {
 		ctx.Error(500, "AddCollaborator", err)
 		return