From f3b24e90dc9fad355102e1fdf2828ca33d447a07 Mon Sep 17 00:00:00 2001 From: Eli Zaretskii Date: Sun, 16 Apr 2017 10:27:23 +0300 Subject: [PATCH] Add assertion to STRING_SET_CHARS * src/lisp.h (STRING_SET_CHARS): Add an assertion and commentary to prevent incorrect usage. For details, see this discussion: http://lists.gnu.org/archive/html/emacs-devel/2017-04/msg00412.html. --- src/lisp.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/lisp.h b/src/lisp.h index 678e261c1da..e0bad58f758 100644 --- a/src/lisp.h +++ b/src/lisp.h @@ -1369,6 +1369,10 @@ SBYTES (Lisp_Object string) INLINE void STRING_SET_CHARS (Lisp_Object string, ptrdiff_t newsize) { + /* This function cannot change the size of data allocated for the + string when it was created. */ + eassert ((STRING_MULTIBYTE (string) && newsize <= SBYTES (string)) + || (!STRING_MULTIBYTE (string) && newsize == SCHARS (string))); XSTRING (string)->size = newsize; } -- 2.39.5