New C macro AUTO_STRING_WITH_LEN

Put a bit less pressure on the garbage collector by defining a
macro that is like AUTO_STRING but also allows null bytes in strings,
and by extending AUTO_STRING to work with any unibyte string.
* src/alloc.c (verify_ascii): Remove; all uses removed.
AUTO_STRING can now be used on non-ASCII unibyte strings.
* src/lisp.h (AUTO_STRING): Now allows non-ASCII unibyte strings.
(AUTO_STRING_WITH_LEN): New macro.
* src/coding.c (from_unicode_buffer):
* src/editfns.c (format_time_string):
* src/emacs-module.c (module_make_string, module_format_fun_env):
* src/fileio.c (Fexpand_file_name):
* src/font.c (font_parse_family_registry):
* src/ftfont.c (ftfont_get_charset):
* src/keymap.c (silly_event_symbol_error):
* src/menu.c (single_menu_item):
* src/sysdep.c (system_process_attributes):
Use AUTO_STRING_WITH_LEN if possible.
* src/emacs-module.c (module_make_function):
* src/fileio.c (report_file_errno, report_file_notify_error):
* src/fns.c (Flocale_info):
* src/sysdep.c (system_process_attributes):
Use AUTO_STRING if possible.  This is doable more often now
that AUTO_STRING works on any unibyte string.

1 files changed, 4 insertions, 5 deletions

diff --git a/src/coding.c b/src/coding.c
index e72d7b71867..bcedd7f5eeb 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -8419,11 +8419,10 @@ from_unicode (Lisp_Object str)
 Lisp_Object
 from_unicode_buffer (const wchar_t *wstr)
 {
-    return from_unicode (
-        make_unibyte_string (
-            (char *) wstr,
-            /* we get one of the two final 0 bytes for free. */
-            1 + sizeof (wchar_t) * wcslen (wstr)));
+  /* We get one of the two final null bytes for free.  */
+  prtdiff_t len = 1 + sizeof (wchar_t) * wcslen (wstr);
+  AUTO_STRING_WITH_LEN (str, (char *) wstr, len);
+  return from_unicode (str);
 }
 
 wchar_t *