EZP-29899: Content loading can end up loading wrong version under concurrency

[andrerom]

Question	Answer
JIRA issue	EZP-29899
Bug	yes
Target version	5.4 and up
BC breaks	no
Tests pass	yes
Doc needed	no

Under concurrency it's possible that current version number we get in content info
is out of date by the time we ask for full content object. So change
SPI to allow loading current version number directly.

TODO:

• Implement feature / fix a bug.
• Implement tests.
• Fix new code according to Coding Standards ($ composer fix-cs).
• Ask for Code Review.
• On MERGE remember to adapt 6.13 and up with:

diff --git a/eZ/Publish/Core/Persistence/Cache/ContentHandler.php b/eZ/Publish/Core/Persistence/Cache/ContentHandler.php
index eccd98924d..f28bdc3c41 100644
--- a/eZ/Publish/Core/Persistence/Cache/ContentHandler.php
+++ b/eZ/Publish/Core/Persistence/Cache/ContentHandler.php
@@ -368,6 +373,7 @@ class ContentHandler extends AbstractHandler implements ContentHandlerInterface
             $languageCode
         );
         $this->cache->clear('content', $contentId, $versionNo);
+        $this->cache->clear('content', $contentId, self::PUBLISHED_VERSION);
         $this->cache->clear('content', 'info', $contentId, 'versioninfo', $versionNo);
 
         return $content;
diff --git a/eZ/Publish/Core/Repository/ContentService.php b/eZ/Publish/Core/Repository/ContentService.php
index e38d78d0f4..92575b2ee2 100644
--- a/eZ/Publish/Core/Repository/ContentService.php
+++ b/eZ/Publish/Core/Repository/ContentService.php
@@ -274,8 +274,3 @@ class ContentService implements ContentServiceInterface
         }
-
-         // As we have content info we can avoid that current version is looked up using spi in loadContent() if not set
-         if ($versionNo === null) {
-             $versionNo = $contentInfo->currentVersionNo;
-         }

        return $this->loadContent(

[alongosz]

Makes perfect sense, some nitpicks:

[alongosz]

Dead code detected 😛

[andrerom]

Fixed :)

[m-tyrala]

Sanity tests passed