Issue #1860876 by pounard: Fixed module_implements_write_cache() should not drop caches when requesting with POST method.

CHANGELOG.txt

@@ -1,6 +1,9 @@
 
 Drupal 7.23, xxxx-xx-xx (development version)
 -----------------------
+- Performance improvement: Allowed all hooks to be included in the
+  module_implements() cache, even those that are only invoked on HTTP POST
+  requests.
 - Made the database system replace truncate queries with delete queries when
   inside a transaction, to fix issues with PostgreSQL and other databases.
 - Fixed a bug which caused nested contextual links to display improperly.

includes/module.inc

@@ -834,10 +834,7 @@ function module_hook_info() {
  */
 function module_implements_write_cache() {
   $implementations = &drupal_static('module_implements');
-  // Check whether we need to write the cache. We do not want to cache hooks
-  // which are only invoked on HTTP POST requests since these do not need to be
-  // optimized as tightly, and not doing so keeps the cache entry smaller.
-  if (isset($implementations['#write_cache']) && ($_SERVER['REQUEST_METHOD'] == 'GET' || $_SERVER['REQUEST_METHOD'] == 'HEAD')) {
+  if (isset($implementations['#write_cache'])) {
     unset($implementations['#write_cache']);
     cache_set('module_implements', $implementations, 'cache_bootstrap');
   }