Previously when HashList was removing items, HashListBlocks were
removed lazily. This resulted in empty HashListBlocks dangling around
in full pages, even when all items have been erased. These blocks
would only be deleted when NVS was re-initialized
(nvs_flash_deinit/nvs_flash_init).
This change does eager cleanup instead, based on the code from
@negativekelvin offered in
https://github.com/espressif/esp-idf/issues/1642#issuecomment-367227994.
Closes https://github.com/espressif/esp-idf/issues/1642.
When erasing a variable length item with an incorrect CRC32, the span
value of the item can not be trusted, so the item will be erased with
span = 1. Subsequent entries represent the data of the variable
length item, and these will be treated as separate items. For each
entry CRC32 is checked, the check most likely fails (because the
entry contains arbitrary data, and not a proper NVS item), and the
entry is erased. Erase function assumed that every item should be
present in cache, but it is not the case for the entries which are
just parts of item’s payload. This change allows for the item to be
not found in the hashlist, if the CRC32 check fails.
* Change snprintf for strlcat does not complain w/gcc7.2.0 and it is safer, thanks @projectgus
* Use proper quotes for character literals
Merges https://github.com/espressif/esp-idf/pull/1163
