Issue #2249723 by andrei.dincu: Do not allow...

Issue #2249723 by andrei.dincu: Do not allow xmlsitemap_sitemap_get_context_hash to modify sitemap context

xmlsitemap.install

@@ -582,7 +582,8 @@ function _xmlsitemap_sitemap_rehash_all() {
   // Force a rehash of all sitemaps.
   $sitemaps = xmlsitemap_sitemap_load_multiple(FALSE);
   foreach ($sitemaps as $sitemap) {
-    $hash = xmlsitemap_sitemap_get_context_hash($sitemap->context);
+    $context = $sitemap->context;
+    $hash = xmlsitemap_sitemap_get_context_hash($context);
     if ($hash != $sitemap->smid) {
       xmlsitemap_sitemap_save($sitemap);
     }

xmlsitemap.module

@@ -446,7 +446,8 @@ function xmlsitemap_sitemap_save(XmlSitemapInterface $sitemap) {
   //$sitemap->is_new = empty($sitemap->getId());
   //$sitemap->old_smid = $sitemap->is_new ? NULL : $sitemap->smid;
   $sitemap->setOriginalId($sitemap->isNew() ? NULL : $sitemap->getId());
-  $sitemap->setId(xmlsitemap_sitemap_get_context_hash($sitemap->getContext()));
+  $context = $sitemap->getContext();
+  $sitemap->setId(xmlsitemap_sitemap_get_context_hash($context));
   // If the context was changed, we need to perform additional actions.
   if (!$sitemap->isNew() && $sitemap->getId() != $sitemap->getOriginalId()) {
     // Rename the files directory so the sitemap does not break.