Unhandled exception when trying to register a duplicate user

Oh, what certainly should happen is some form of validation, which certainly exists, but somehow doesn't work, see core/modules/user/src/Entity/User.php:463

this issue seems to be introduced by #2395831: Entity forms skip validation of fields that are not in the EntityFormDisplay

Damn

Working on test coverage ...

There we go.

Test looks good, you've left the test > ptest changes in a few places

wrong comment

So the actual problem is that the anonymous user is not allowed to edit the username

1. +++ b/core/modules/user/src/UserAccessControlHandler.php
   @@ -81,9 +81,13 @@ protected function checkFieldAccess($operation, FieldDefinitionInterface $field_
   +        // Anonymous users should be able to change their usernamae
   

   %s/usernamae/username - and needs a trailing .

2. +++ b/core/modules/user/src/UserAccessControlHandler.php
   @@ -81,9 +81,13 @@ protected function checkFieldAccess($operation, FieldDefinitionInterface $field_
   +        if ($account->isAnonymous()) {
   +          return AccessResult::allowed();
   +        }
   

   Is this hunk still needed, shouldn't the first hunk cover the issue? Surely anonymous users shouldn't have access to all operations on the name field?

as for #12

+++ b/core/modules/user/src/UserAccessControlHandler.php
@@ -81,13 +81,10 @@
-        if ($account->isAnonymous()) {
-          return AccessResult::allowed();
-        }

Right, that was the first way how I tried to solve it ...

Did some manual testing of patch #13 and it still is throwing the same exception for me. Ran git apply, purged db and re-installed. Followed the steps to re-create exactly as posted.

@EvanSchisler This is what I get running drupal HEAD version and apply patch from #13

Sorry guys! I made a mistake and the patch did not apply properly to the UserAccessControlHandler.php file.
I am fairly new to patching.
Re-patched and tested and every showing up the same as @willzyx.

I just ran into that issue so I'm glad someone already noticed it.
Here is the updated patch.

Needs a reroll.

The fix is pretty oblique - why is the anonymous user name name changing here?

rerolled

// Anonymous users should be able to change their username.

Sure, the comment is misleading.. should be something like

// Anonymous users should be able to change their username during the registration process, otherwise the username constraints are not checked.

I'm not really convinced by the solution. Why does the \Drupal\user\Plugin\Validation\Constraint\UserNameUnique not trigger here, it really should!

Oh I know, because it is only executed on access, nevermind.

1. +++ b/core/modules/user/src/Tests/UserRegistrationTest.php
   @@ -265,6 +266,23 @@ function testRegistrationDefaultValues() {
   +   * Tests registration errors when trying to register with an existing user
   

   Function description cannot be multiline

2. +++ b/core/modules/user/src/Tests/UserRegistrationTest.php
   @@ -265,6 +266,23 @@ function testRegistrationDefaultValues() {
   +    $this->drupalPostForm('user/register', ['mail' => 'test@example.com', 'name' => $account->getUsername()], t('Create new account'));
   ...
   +    $this->drupalPostForm('user/register', ['mail' => $account->getEmail(), 'name' => $this->randomString()], t('Create new account'));
   

   These would be cleaner if they would be put on multiple lines.

3. +++ b/core/modules/user/src/Tests/UserRegistrationTest.php
   @@ -265,6 +266,23 @@ function testRegistrationDefaultValues() {
   +    $this->assertRaw(Safemarkup::format('The username %value is already taken.', ['%value' => $account->getUsername()]));
   ...
   +    $this->assertRaw(Safemarkup::format('The email address %value is already taken.', ['%value' => $account->getEmail()]));
   

   s/Safemarkup/SafeMarkup

4. +++ b/core/modules/user/src/UserAccessControlHandler.php
   @@ -81,7 +81,9 @@ protected function checkFieldAccess($operation, FieldDefinitionInterface $field_
   +        // Anonymous users should be able to change their username during the registration process,
   

   This is over 80 characters

Updated with all lauriii's changes

+++ b/core/modules/user/src/Tests/UserRegistrationTest.php
@@ -265,6 +266,36 @@ function testRegistrationDefaultValues() {
+      ['mail' => 'test@example.com', 'name' => $account->getUsername()],
...
+      ['mail' => $account->getEmail(), 'name' => $this->randomString()],

Lets create variable for these like $values = ['mail' => 'test@exmaple.com'] etc. Then we can have these on a single line.

b0unty: Whats the difference between the two strings on #42.2?

Looks a lot better.

+1 for RTBC
Thank you all for your work on this issue !

This issue addresses a major bug and is allowed per https://www.drupal.org/core/beta-changes. Committed a66929c and pushed to 8.0.x. Thanks!