Fix #79489: .user.ini does not inherit

On Windows, PATH_TRANSLATED may contain backslashes as well as slashes,
so we must not only check for `DEFAULT_SLASH`.

Author: cmb69

NEWS

@@ -4,6 +4,7 @@ PHP                                                                        NEWS
 
 - Core:
   . Fixed bug #79566 (Private SHM is not private on Windows). (cmb)
+  . Fixed bug #79489 (.user.ini does not inherit). (cmb)
 
 - Opcache:
   . Fixed bug #79535 (PHP crashes with specific opcache.optimization_level).

sapi/cgi/cgi_main.c

@@ -843,7 +843,11 @@ static void php_cgi_ini_activate_user_config(char *path, size_t path_len, const
 		if (strncmp(s1, s2, s_len) == 0) {
 #endif
 			char *ptr = s2 + doc_root_len;
+#ifdef PHP_WIN32
+			while ((ptr = strpbrk(ptr, "\\/")) != NULL) {
+#else
 			while ((ptr = strchr(ptr, DEFAULT_SLASH)) != NULL) {
+#endif
 				*ptr = 0;
 				php_parse_user_ini_file(path, PG(user_ini_filename), entry->user_config);
 				*ptr = '/';