[PATCH 2/3] lib/charset: add u16_strcat() function

[Heinrich Schuchardt]

On 2/10/22 08:05, Masahisa Kojima wrote:
> Provide u16 string version of strcat().
>
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>

Please, provide a test in test/unicode_ut.c.
> ---
>   include/charset.h | 13 +++++++++++++
>   lib/charset.c     | 12 ++++++++++++
>   2 files changed, 25 insertions(+)
>
> diff --git a/include/charset.h b/include/charset.h
> index b93d023092..baba9d7c14 100644
> --- a/include/charset.h
> +++ b/include/charset.h
> @@ -259,6 +259,19 @@ u16 *u16_strcpy(u16 *dest, const u16 *src);
>    */
>   u16 *u16_strdup(const void *src);
>
> +/**
> + * u16_strcat() - append u16 string
> + *
> + * Append the src string to the dest string, overwriting the terminating
> + * null word at the end of dest, and then adds a terminating null word.
> + * The dest string must have enough space for the result.
> + *
> + * @dest:		destination buffer (null terminated)
> + * @src:		source buffer (null terminated)
> + * Return:		'dest' address
> + */
> +u16 *u16_strcat(u16 *dest, const u16 *src);

This is unsafe. Please, provide an argument for the destination buffer
size. If you still need a version without the argument, simply use a
define like we did for other functions.

Best regards

Heinrich

> +
>   /**
>    * utf16_to_utf8() - Convert an utf16 string to utf8
>    *
> diff --git a/lib/charset.c b/lib/charset.c
> index f44c58d9d8..f0eaf6c1ae 100644
> --- a/lib/charset.c
> +++ b/lib/charset.c
> @@ -428,6 +428,18 @@ u16 *u16_strdup(const void *src)
>   	return new;
>   }
>
> +u16 *u16_strcat(u16 *dest, const u16 *src)
> +{
> +	u16 *tmp = dest;
> +
> +	while (*dest)
> +		dest++;
> +	while ((*dest++ = *src++) != u'\0')
> +		;
> +
> +	return tmp;
> +}
> +
>   /* Convert UTF-16 to UTF-8.  */
>   uint8_t *utf16_to_utf8(uint8_t *dest, const uint16_t *src, size_t size)
>   {