Repository: Fix broken conversion rules

The additional layers in $aliasTableMap and $aliasColumnMap required
for DbRepository's join probabilities are now only established there.

library/Icinga/Repository/DbRepository.php

@@ -235,6 +235,29 @@ abstract class DbRepository extends Repository implements Extensible, Updatable,
         return $queryColumns;
     }
 
+    /**
+     * Initialize table, column and alias maps
+     *
+     * @throws  ProgrammingError    In case $this->queryColumns does not provide any column information
+     */
+    protected function initializeAliasMaps()
+    {
+        parent::initializeAliasMaps();
+
+        foreach ($this->aliasTableMap as $alias => $table) {
+            if ($table !== null) {
+                if (strpos($alias, '.') !== false) {
+                    $prefixedAlias = str_replace('.', '_', $alias);
+                } else {
+                    $prefixedAlias = $table . '_' . $alias;
+                }
+
+                $this->aliasTableMap[$prefixedAlias] = $table;
+                $this->aliasColumnMap[$prefixedAlias] = $this->aliasColumnMap[$alias];
+            }
+        }
+    }
+
     /**
      * Return the given table with the datasource's prefix being prepended
      *

library/Icinga/Repository/Repository.php

@@ -644,11 +644,6 @@ abstract class Repository implements Selectable
         }
 
         foreach ($queryColumns as $table => $columns) {
-            foreach ($columns as $alias => $column) {
-                $alias = is_string($alias) ? $alias : $column;
-                $columns[$table . '_' . $alias] = $column;
-            }
-
             foreach ($columns as $alias => $column) {
                 if (! is_string($alias)) {
                     $key = $column;