Change in flashrom[master]: libflashrom,writeprotect: add flashrom_wp_get_available_ranges()

[Nico Huber (Code Review)]

Attention is currently required from: Edward O'Callaghan, Angel Pons, Anastasia Klimchuk, Nikolai Artemiev, Sergii Dmytruk.
Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/58481 )

Change subject: libflashrom,writeprotect: add flashrom_wp_get_available_ranges()
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Patch Set 10:

(2 comments)

File writeprotect.c:

https://review.coreboot.org/c/flashrom/+/58481/comment/8c9d3160_7ece42e9 
PS10, Line 271: ranges[++last] = ranges[i];
> I don't understand how it works :(( this assignment... […]

In the first iteration (last == 0, i == 0), it would compare the same
element, hence `duplicate` would be `true` and this line would be skipped.

In further iterations, `last` would at least be one less than `i`, hence
it would potentially overwrite duplicates (at `last + 1`) with later elements
at `i`.

It's hard to read, indeed. Starting the loop at `i == 1` might make things
easier.

And there is at least one (theoretical?) case where the code fails, see
below.

https://review.coreboot.org/c/flashrom/+/58481/comment/dfc5b99e_92f14bdb 
PS10, Line 274: 	*count = last + 1;
If `*count` was 0 initially, i.e. an empty list, this would set it to `1`.