minor #10717 unified return null usages (fabpot)

This PR was merged into the 2.3 branch.

Discussion
----------

unified return null usages

| Q             | A
| ------------- | ---
| License       | MIT

This PR unifies the way we return `null` from a function or method:

 * always use `return;` instead of `return null;` (the current code base uses both);
 * never use `return;` at the end of a function/method.

Commits
-------

d1d569b unified return null usages

9 files changed, 10 insertions, 13 deletions

diff --git a/Acl/Domain/DoctrineAclCache.php b/Acl/Domain/DoctrineAclCache.php
index b680fb1..9e14af5 100644
--- a/Acl/Domain/DoctrineAclCache.php
+++ b/Acl/Domain/DoctrineAclCache.php
@@ -96,14 +96,14 @@ class DoctrineAclCache implements AclCacheInterface
     {
         $lookupKey = $this->getAliasKeyForIdentity($aclId);
         if (!$this->cache->contains($lookupKey)) {
-            return null;
+            return;
         }
 
         $key = $this->cache->fetch($lookupKey);
         if (!$this->cache->contains($key)) {
             $this->cache->delete($lookupKey);
 
-            return null;
+            return;
         }
 
         return $this->unserializeAcl($this->cache->fetch($key));
@@ -116,7 +116,7 @@ class DoctrineAclCache implements AclCacheInterface
     {
         $key = $this->getDataKeyByIdentity($oid);
         if (!$this->cache->contains($key)) {
-            return null;
+            return;
         }
 
         return $this->unserializeAcl($this->cache->fetch($key));
@@ -154,7 +154,7 @@ class DoctrineAclCache implements AclCacheInterface
             $parentAcl = $this->getFromCacheById($parentId);
 
             if (null === $parentAcl) {
-                return null;
+                return;
             }
 
             $acl->setParentAcl($parentAcl);
diff --git a/Acl/Domain/ObjectIdentityRetrievalStrategy.php b/Acl/Domain/ObjectIdentityRetrievalStrategy.php
index 7dc552c..fc66856 100644
--- a/Acl/Domain/ObjectIdentityRetrievalStrategy.php
+++ b/Acl/Domain/ObjectIdentityRetrievalStrategy.php
@@ -29,7 +29,7 @@ class ObjectIdentityRetrievalStrategy implements ObjectIdentityRetrievalStrategy
         try {
             return ObjectIdentity::fromDomainObject($domainObject);
         } catch (InvalidDomainObjectException $failed) {
-            return null;
+            return;
         }
     }
 }
diff --git a/Acl/Permission/BasicPermissionMap.php b/Acl/Permission/BasicPermissionMap.php
index 30d801f..fa3d543 100644
--- a/Acl/Permission/BasicPermissionMap.php
+++ b/Acl/Permission/BasicPermissionMap.php
@@ -92,7 +92,7 @@ class BasicPermissionMap implements PermissionMapInterface
     public function getMasks($permission, $object)
     {
         if (!isset($this->map[$permission])) {
-            return null;
+            return;
         }
 
         return $this->map[$permission];
diff --git a/Core/Authentication/Provider/AnonymousAuthenticationProvider.php b/Core/Authentication/Provider/AnonymousAuthenticationProvider.php
index ea91075..7fbbf85 100644
--- a/Core/Authentication/Provider/AnonymousAuthenticationProvider.php
+++ b/Core/Authentication/Provider/AnonymousAuthenticationProvider.php
@@ -40,7 +40,7 @@ class AnonymousAuthenticationProvider implements AuthenticationProviderInterface
     public function authenticate(TokenInterface $token)
     {
         if (!$this->supports($token)) {
-            return null;
+            return;
         }
 
         if ($this->key !== $token->getKey()) {
diff --git a/Core/Authentication/Provider/PreAuthenticatedAuthenticationProvider.php b/Core/Authentication/Provider/PreAuthenticatedAuthenticationProvider.php
index 3affd78..21ce8d0 100644
--- a/Core/Authentication/Provider/PreAuthenticatedAuthenticationProvider.php
+++ b/Core/Authentication/Provider/PreAuthenticatedAuthenticationProvider.php
@@ -53,7 +53,7 @@ class PreAuthenticatedAuthenticationProvider implements AuthenticationProviderIn
      public function authenticate(TokenInterface $token)
      {
          if (!$this->supports($token)) {
-             return null;
+             return;
          }
 
         if (!$user = $token->getUser()) {
diff --git a/Core/Authentication/Provider/UserAuthenticationProvider.php b/Core/Authentication/Provider/UserAuthenticationProvider.php
index 14fbdda..3728c01 100644
--- a/Core/Authentication/Provider/UserAuthenticationProvider.php
+++ b/Core/Authentication/Provider/UserAuthenticationProvider.php
@@ -58,7 +58,7 @@ abstract class UserAuthenticationProvider implements AuthenticationProviderInter
     public function authenticate(TokenInterface $token)
     {
         if (!$this->supports($token)) {
-            return null;
+            return;
         }
 
         $username = $token->getUsername();
diff --git a/Core/User/User.php b/Core/User/User.php
index b378e1b..ea2c6a4 100644
--- a/Core/User/User.php
+++ b/Core/User/User.php
@@ -64,7 +64,6 @@ final class User implements AdvancedUserInterface
      */
     public function getSalt()
     {
-        return null;
     }
 
     /**
diff --git a/Http/Firewall/ContextListener.php b/Http/Firewall/ContextListener.php
index 60ab3df..c4b0a1e 100644
--- a/Http/Firewall/ContextListener.php
+++ b/Http/Firewall/ContextListener.php
@@ -171,7 +171,7 @@ class ContextListener implements ListenerInterface
                     $this->logger->warning(sprintf('Username "%s" could not be found.', $notFound->getUsername()));
                 }
 
-                return null;
+                return;
             }
         }
 
diff --git a/Http/RememberMe/AbstractRememberMeServices.php b/Http/RememberMe/AbstractRememberMeServices.php
index 1e60db0..be84208 100644
--- a/Http/RememberMe/AbstractRememberMeServices.php
+++ b/Http/RememberMe/AbstractRememberMeServices.php
@@ -142,8 +142,6 @@ abstract class AbstractRememberMeServices implements RememberMeServicesInterface
         }
 
         $this->cancelCookie($request);
-
-        return null;
     }
 
     /**