Add the ZEND_DONT_UNLOAD_MODULES environment variable for debugging to 5.3 as

well.

Author: Derick Rethans

Zend/README.ZEND_MM

@@ -24,6 +24,14 @@ Zend MM disabled:
 
     $ USE_ZEND_ALLOC=0 valgrind --leak-check=full sapi/cli/php -r 'leak();'
 
+Shared extensions:
+------------------
+
+Since PHP 5.4 it is possible to prevent shared extensions from unloading so
+that valgrind can correctly track the memory leaks in shared extensions. For
+this there is the ZEND_DONT_UNLOAD_MODULES environment variable. If set, then
+DL_UNLOAD() is skipped during the shutdown of shared extensions.
+
 Tweaking:
 ---------
 

Zend/zend_API.c

@@ -2137,7 +2137,7 @@ void module_destructor(zend_module_entry *module) /* {{{ */
 
 #if HAVE_LIBDL
 #if !(defined(NETWARE) && defined(APACHE_1_BUILD))
-	if (module->handle) {
+	if (module->handle && !getenv("ZEND_DONT_UNLOAD_MODULES")) {
 		DL_UNLOAD(module->handle);
 	}
 #endif