protected virtual async Task <AuthenticateResult> UpdateAccountFromExternalClaimsAsync(TKey userID, string provider, string providerId, IEnumerable <Claim> claims)
{
var existingClaims = await userManager.GetClaimsAsync(userID);
var intersection = existingClaims.Intersect(claims, new ClaimComparer());
var newClaims = claims.Except(intersection, new ClaimComparer());
foreach (var claim in newClaims)
{
var result = await userManager.AddClaimAsync(userID, claim);
if (!result.Succeeded)
{
return(new AuthenticateResult(result.Errors.First()));
}
}
return(null);
}
