Free memory just before returning from proc_open

Setting these pointers to NULL after freeing them was necessary because if an error
occurred later on, they could be double-freed after 'goto exit_fail'. It is simpler
to free them after all possible sources of error are past.

Author: alexdowad

ext/standard/proc_open.c

@@ -1019,13 +1019,6 @@ PHP_FUNCTION(proc_open)
 	newprocok = CreateProcessW(NULL, cmdw, &php_proc_open_security, &php_proc_open_security,
 		TRUE, dwCreateFlags, envpw, cwdw, &si, &pi);
 
-	free(cwdw);
-	cwdw = NULL;
-	free(cmdw);
-	cmdw = NULL;
-	free(envpw);
-	envpw = NULL;
-
 	if (suppress_errors) {
 		SetErrorMode(old_error_mode);
 	}
@@ -1187,7 +1180,11 @@ PHP_FUNCTION(proc_open)
 		}
 	}
 
-#ifndef PHP_WIN32
+#ifdef PHP_WIN32
+	free(cwdw);
+	free(cmdw);
+	free(envpw);
+#else
 	efree_argv(argv);
 #endif