Issue #2818923 by claudiu.cristea: Row index passed to keys triggers exception

src/Plugin/migrate/source/Spreadsheet.php

@@ -99,6 +99,9 @@ class Spreadsheet extends SourcePluginBase implements ConfigurablePluginInterfac
    */
   public function fields() {
     $columns = $this->getConfiguration()['columns'];
+    if (!empty($row_index_column = $this->getConfiguration()['row_index_colums'])) {
+      $columns[] = $row_index_column;
+    }
     return array_combine($columns, $columns);
   }
 

src/SpreadsheetIterator.php

@@ -97,14 +97,16 @@ class SpreadsheetIterator implements SpreadsheetIteratorInterface {
    * {@inheritdoc}
    */
   public function current() {
-    if (empty($keys = $this->getKeys())) {
-      $row_index_column = $this->getRowIndexColumn();
-      if (!$row_index_column) {
+    $all_columns = $this->getKeys() + $this->getColumns();
+
+    if ($row_index_column = $this->getRowIndexColumn()) {
+      $all_columns[$row_index_column] = -1;
+    }
+    else {
+      if (empty($keys = $this->getKeys())) {
         throw new \InvalidArgumentException("Row index should act as key but no name has been provided. Pass a string in \$config['row_index_column'] key when setting the configuration in SpreadsheetIterator::setConfiguration(\$config), to provide a name for this column.");
       }
-      $keys = [$row_index_column => -1];
     }
-    $all_columns = $keys + $this->getColumns();
 
     // Arrange columns in their spreadsheet native order.
     asort($all_columns);
@@ -192,7 +194,7 @@ class SpreadsheetIterator implements SpreadsheetIteratorInterface {
         $headers = $this->getHeaders();
         $this->keys = [];
         foreach ($this->configuration['keys'] as $key) {
-          if (!isset($headers[$key])) {
+          if ($key != $this->getRowIndexColumn() && !isset($headers[$key])) {
             throw new \InvalidArgumentException("Key '$key' doesn't exist in the table header.");
           }
           $this->keys[$key] = $headers[$key];