Re: [PATCH v3 1/2] add strbuf_set operations

> A common use case with strubfs is to set the buffer to a new value.
> This must be done in two steps: a reset followed by an add.
> 
>   strbuf_reset(buf);
>   strbuf_add(buf, new_buf, len);
> 
> In cases where the buffer is being built up in steps, these operations
> make sense and correctly convey what is being performed.
> 
>   strbuf_reset(buf);
>   strbuf_add(buf, data1, len1);
>   strbuf_add(buf, data2, len2);
>   strbuf_add(buf, data3, len3);
> 
> However, in other cases, it can be confusing and is not very concise.
> 
>   strbuf_reset(buf);
>   strbuf_add(buf, default, len1);
> 
>   if (cond1) {
>     strbuf_reset(buf);
>     strbuf_add(buf, data2, len2);
>   }
> 
>   if (cond2) {
>     strbuf_reset(buf);
>     strbuf_add(buf, data3, len3);
>   }
> 
> Add strbuf_set operations so that it can be re-written in a clear and
> concise way.
> 
>   strbuf_set(buf, default len1);