[1.1.61] Merged items doesn't count as consumed in statistics

[Evi1]

Some items(such as Science Packs, Repair Packs, Ammo Magazines) has "durability", that shows on how much this item was already used. When you combine two used items into one stack, these durability merged, and as result you will have "new" items with resulting summing durability. If summed durability of combined items are less that 100%, than at result you will have one item. But second item just will disappear from game, and will not count as consumed in statistics panel.

Simple "how to" reproduction:
1) Make two Repair Packs
2) Use first one, down to less 50% durability. At example 25%
3) Drop this used Repairs to ground\chest
4) Use second, also down to less 50%. At example 40%
5) Get first one back. At result you will have just one Repair Pack with summing durability 25%+40%=65%. And its OK
6) But statistics panel will not show, that one of these was consumed. And this is problem, which I mean
7) Even if you will use that Repair Pack up to end, statistics will show that only one Repair was consumed, but produced - two. Second one just was "purged" without any trace...

Actually, I found this bug when saw that my factory consumes one type of Science Pack, less that others(using Lab-to-Lab inserters method), for long time. And as it turned out, one type of Science Packs, in one of my Lab periodically(!!) merges with this "purging"... and it was continued for hours!
Here is 50 hours statistics screenshot:

And in numbers(left part - produced, right - consumed):

~1k of Red and Green Packs was gone from statistics, for 50 hours gameplay. Seems not very normal.

[Loewchen]

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