Fixes #4491 Prevent Random error by catching the Exception in case th…

…e subtable is not found.

Adding test that reproduced the issue and then shows it's fixed.

core/DataTable.php

@@ -20,6 +20,7 @@
 use Piwik\DataTable\Row;
 use Piwik\DataTable\Row\DataTableSummaryRow;
 use Piwik\DataTable\Simple;
+use Piwik\DataTable\TableNotFoundException;
 use ReflectionClass;
 
 /**
@@ -315,7 +316,7 @@ class DataTable implements DataTableInterface
     public function __construct()
     {
         // registers this instance to the manager
-        $this->currentId = Manager::getInstance()->addTable($this);
+        $this->currentId = Manager::getInstance()-> addTable($this);
     }
 
     /**
@@ -1102,7 +1103,16 @@ public function getSerialized($maximumRowsInDataTable = null,
         $aSerializedDataTable = array();
         foreach ($this->rows as $row) {
             if (($idSubTable = $row->getIdSubDataTable()) !== null) {
-                $subTable = Manager::getInstance()->getTable($idSubTable);
+                $subTable = null;
+                try {
+                    $subTable = Manager::getInstance()->getTable($idSubTable);
+                } catch(TableNotFoundException $e) {
+                    // This occurs is an unknown & random data issue. Catch Exception and remove subtable from the row.
+                    $row->removeSubtable();
+                    // Go to next row
+                    continue;
+                }
+
                 $depth++;
                 $aSerializedDataTable = $aSerializedDataTable + $subTable->getSerialized($maximumRowsInSubDataTable, $maximumRowsInSubDataTable, $columnToSortByBeforeTruncation);
                 $depth--;

core/DataTable/Manager.php

@@ -65,7 +65,7 @@ public function addTable($table)
     public function getTable($idTable)
     {
         if (!isset($this->tables[$idTable])) {
-            throw new Exception(sprintf("This report has been reprocessed since your last click. To see this error less often, please increase the timeout value in seconds in Settings > General Settings. (error: id %s not found).", $idTable));
+            throw new TableNotFoundException(sprintf("This report has been reprocessed since your last click. To see this error less often, please increase the timeout value in seconds in Settings > General Settings. (error: id %s not found).", $idTable));
         }
         return $this->tables[$idTable];
     }

core/DataTable/TableNotFoundException.php

@@ -0,0 +1,17 @@
+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\DataTable;
+
+
+class TableNotFoundException extends \Exception
+{
+
+}

tests/PHPUnit/Core/DataTableTest.php

@@ -777,6 +777,50 @@ public function testSubDataTableIsDestructed()
         Common::destroy($rowBeingDestructed);
     }
 
+    public function test_serializeFails_onSubTableNotFound()
+    {
+        // create a simple table with a subtable
+        $table1 = $this->_getDataTable1ForTest();
+        $table2 = $this->_getDataTable2ForTest();
+        $table2->getFirstRow()->addSubtable($table1);
+        $idSubtable = $table1->getId();
+
+
+        /* Check it looks good:
+        $renderer = DataTable\Renderer::factory('xml');
+        $renderer->setTable($table2);
+        $renderer->setRenderSubTables(true);
+        echo $renderer->render();
+        */
+
+        // test serialize:
+        // - subtable is serialized as expected
+        $serializedStrings = $table2->getSerialized();
+
+        // both the main table and the sub table are serialized
+        $this->assertEquals(sizeof($serializedStrings), 2);
+        $serialized = implode(",", $serializedStrings);
+
+        // the serialized string references the id subtable
+        $this->assertTrue( false !== strpos($serialized, 'i:' . $idSubtable), "not found the id sub table in the serialized, not expected");
+
+        // KABOOM, we delete the subtable, reproducing a "random data issue"
+        Manager::getInstance()->deleteTable($idSubtable);
+
+        // Now we will serialize this "broken datatable" and check it works.
+
+        // - it does not throw an exception
+        $serializedStrings = $table2->getSerialized();
+
+        // - the serialized table does NOT contain the sub table
+        $this->assertEquals(sizeof($serializedStrings), 1); // main table only is serialized
+        $serialized = implode(",", $serializedStrings);
+
+        // - the serialized string does NOT contain the id subtable (the row was cleaned up as expected)
+        $this->assertTrue( false === strpos($serialized, 'i:' . $idSubtable), "found the id sub table in the serialized, not expected");
+
+    }
+
     protected function _getDataTable1ForTest()
     {
         $rows = $this->_getRowsDataTable1ForTest();