[PATCH 4/5] editor: Improve checks on delete add asserts

[Bill Spitzak]

On 05/30/2013 04:57 AM, Jan Arne Petersen wrote:

> -	if (entry->pending_commit.delete_index + length > text_length) {
> +	if (length > text_length ||
> +	    entry->pending_commit.delete_index + length > text_length) {

This is to detect wrap-around of the unsigned values, right? This is 
annoyingly complex to get right. Checking if delete_index > text_length 
as well will fix it if text_length is less than the first value with the 
high bit set. The real check is not much more complex but I don't want 
to get it wrong here...

>   		fprintf(stderr, "Invalid length %d\n", length);
>   		entry->pending_commit.delete_length = 0;

I think it would be better to truncate it at text_length.