From 522cc87fdc25449222a5894a428eebf4b8d5eaa9 Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Thu, 1 Dec 2022 15:46:53 +0100 Subject: utf8: fix truncated string lengths in `utf8_strnwidth()` The `utf8_strnwidth()` function accepts an optional string length as input parameter. This parameter can either be set to `-1`, in which case we call `strlen()` on the input. Or it can be set to a positive integer that indicates a precomputed length, which callers typically compute by calling `strlen()` at some point themselves. The input parameter is an `int` though, whereas `strlen()` returns a `size_t`. This can lead to implementation-defined behaviour though when the `size_t` cannot be represented by the `int`. In the general case though this leads to wrap-around and thus to negative string sizes, which is sure enough to not lead to well-defined behaviour. Fix this by accepting a `size_t` instead of an `int` as string length. While this takes away the ability of callers to simply pass in `-1` as string length, it really is trivial enough to convert them to instead pass in `strlen()` instead. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- utf8.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'utf8.h') diff --git a/utf8.h b/utf8.h index fcd5167baf..6da1b6d05e 100644 --- a/utf8.h +++ b/utf8.h @@ -7,7 +7,7 @@ typedef unsigned int ucs_char_t; /* assuming 32bit int */ size_t display_mode_esc_sequence_len(const char *s); int utf8_width(const char **start, size_t *remainder_p); -int utf8_strnwidth(const char *string, int len, int skip_ansi); +int utf8_strnwidth(const char *string, size_t len, int skip_ansi); int utf8_strwidth(const char *string); int is_utf8(const char *text); int is_encoding_utf8(const char *name); -- cgit v1.3