⏫ Forwardport of #12304 to 2.3-develop branch

Applied pull request patch https://github.com/magento/magento2/pull/12304.patch (created by @FreekVandeursen) based on commit(s):
  1. 470c257
  2. 3d1d027
  3. 723452c

Author: magento-engcom-team

dev/tests/integration/testsuite/Magento/Framework/App/Language/_files/bar/en_gb/1.csv

@@ -1,2 +1,3 @@
 four and 75/100,4.75
-four and 5/10,4.50
+four and 5/10,4.50
+

lib/internal/Magento/Framework/App/Language/Dictionary.php

@@ -193,7 +193,9 @@ private function readPackCsv($vendor, $package)
             foreach ($foundCsvFiles as $foundCsvFile) {
                 $file = $directoryRead->openFile($foundCsvFile);
                 while (($row = $file->readCsv()) !== false) {
-                    $result[$row[0]] = $row[1];
+                    if (is_array($row) && count($row) > 1) {
+                        $result[$row[0]] = $row[1];
+                    }
                 }
             }
         }