[cairo] [PATCH] Ensure null-terminated result from strncpy()

[Bill Spitzak]

On 08/28/2015 01:25 PM, Bryce Harrington wrote:
> Signed-off-by: Bryce Harrington <bryce at osg.samsung.com>
> ---
>   src/cairo-scaled-font-subsets.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/src/cairo-scaled-font-subsets.c b/src/cairo-scaled-font-subsets.c
> index 2121761..196fa99 100644
> --- a/src/cairo-scaled-font-subsets.c
> +++ b/src/cairo-scaled-font-subsets.c
> @@ -1206,10 +1206,12 @@ _cairo_scaled_font_subset_create_glyph_names (cairo_scaled_font_subset_t *subset
>
>   	if (utf16_len == 1) {
>   	    int ch = _cairo_unicode_to_winansi (utf16[0]);
> -	    if (ch > 0 && _cairo_winansi_to_glyphname (ch))
> +	    if (ch > 0 && _cairo_winansi_to_glyphname (ch)) {
>   		strncpy (buf, _cairo_winansi_to_glyphname (ch), sizeof (buf));
> -	    else
> +		buf[sizeof (buf)-1] = '\0';
> +	    } else {
>   		snprintf (buf, sizeof (buf), "uni%04X", (int) utf16[0]);
> +	    }

snprintf(buf, sizeof(buf), "%s", _cairo_winansi_to_glyphname(ch)) will 
do what you want, it will truncated with a nul byte at the correct 
point, and not waste time filling the rest of the buffer with nul.

Of course you could also use strlcpy...