Don't error if same invite accepted twice

If a user clicks the same invitation link twice, he should not get an
error message, he should just be taken to his home page. He's already a
member of the project, so trying to join the project should not error
but just succeed silently.

backend/LexBoxApi/Controllers/UserController.cs

@@ -156,11 +156,23 @@ private void UpdateUserMemberships(LexAuthUser? jwtUser, User userEntity)
  // This audience check is redundant now because of [RequireAudience(LexboxAudience.RegisterAccount, true)], but let's leave it in for safety
  if (jwtUser?.Audience == LexboxAudience.RegisterAccount && jwtUser.Projects.Length > 0)
  {
- userEntity.Projects.AddRange(jwtUser.Projects.Select(p => new ProjectUsers { Role = p.Role, ProjectId = p.ProjectId }));
+ foreach (var p in jwtUser.Projects)
+ {
+ if (!userEntity.Projects.Exists(proj => proj.Id == p.ProjectId))
+ {
+ userEntity.Projects.Add(new ProjectUsers { Role = p.Role, ProjectId = p.ProjectId });
+ }
+ }
  }
  if (jwtUser?.Audience == LexboxAudience.RegisterAccount && jwtUser.Orgs.Length > 0)
  {
- userEntity.Organizations.AddRange(jwtUser.Orgs.Select(o => new OrgMember { Role = o.Role, OrgId = o.OrgId }));
+ foreach (var o in jwtUser.Orgs)
+ {
+ if (!userEntity.Organizations.Exists(org => org.Id == o.OrgId))
+ {
+ userEntity.Organizations.Add(new OrgMember { Role = o.Role, OrgId = o.OrgId });
+ }
+ }
  }
  }