PhpUnitJunit tries to load invalid xml file

Work around outup from phpunit versions before 6.5.7/7.0.2 (before sebastianbergmann/phpunit#2974 was fixed).

src/Plugin/Util/PhpUnitResultJunit.php

@@ -139,8 +139,41 @@ private function loadResultFile()
             return new \SimpleXMLElement('<empty/>'); // new empty element
         }
 
-        if (true) {
+        try {
             $suites = simplexml_load_file($this->outputFile);
+        } catch (\Exception $ex) {
+            $suites = null;
+        } catch (\Throwable $ex) { // since php7
+            $suites = null;
+        }
+        if (!$suites) {
+            // from https://stackoverflow.com/questions/7766455/how-to-handle-invalid-unicode-with-simplexml/8092672#8092672
+            $oldUse = libxml_use_internal_errors(true);
+            libxml_clear_errors();
+            $dom = new \DOMDocument("1.0", "UTF-8");
+            $dom->strictErrorChecking = false;
+            $dom->validateOnParse = false;
+            $dom->recover = true;
+            $dom->loadXML(strtr(
+                file_get_contents($this->outputFile),
+                array('&quot;' => "'") // &quot; in attribute names may mislead the parser
+            ));
+
+            /**
+             * @var \LibXMLError
+             */
+            $xmlError = libxml_get_last_error();
+            if ($xmlError) {
+                $warning = sprintf('L%s C%s: %s', $xmlError->line, $xmlError->column, $xmlError->message);
+                print 'WARNING: ignored errors while reading phpunit result, '.$warning."\n";
+            }
+            if (!$dom->hasChildNodes()) {
+                $this->internalProblem('xml file with no content');
+            }
+            $suites = simplexml_import_dom($dom);
+
+            libxml_clear_errors();
+            libxml_use_internal_errors($oldUse);
         }
 
         return $suites;