A villager has an item in it's inventory:
/data get entity <villager> Inventory
Villager has the following entity data: [{id: "minecraft:bread", Count: 1b}]
If we now set the count of that Item to one nothing happens, as this is already the count. This is expected behavior. If we set it to 3 however, the Count gets increased by 3 instead of set to 3.
/data modify entity <villager> Inventory[0].Count set value 3b
/data get entity <villager> Inventory
Villager has the following entity data: [{id: "minecraft:bread", Count: 4b}]
If we now set the count to two, we increase the count by two.
/data modify entity <villager> Inventory[0].Count set value 2b
/data get entity <villager> Inventory
Villager has the following entity data: [{id: "minecraft:bread", Count: 5b}]
Expected behavior:
/data get entity <villager> Inventory
Villager has the following entity data: [{id: "minecraft:bread", Count: 1b}]
/data modify entity <villager> Inventory[0].Count set value 3b
/data get entity <villager> Inventory
Villager has the following entity data: [{id: "minecraft:bread", Count: 3b}]
/data modify entity <villager> Inventory[0].Count set value 2b
/data get entity <villager> Inventory
Villager has the following entity data: [{id: "minecraft:bread", Count: 2b}]
Linked issues
Comments


According to the original issue this had been resolved at 26/Jan/17, before the 1.19.2 update was released, therefore this has to be a separate issue.
The other possibility is, that the original issue has not been resolved and is incorrectly tagged as resolved, so which snapshot was this fixed in?

https://bugs.mojang.com/browse/MC-112826?focusedId=1206119&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-1206119
The report was originally (and still resolved as) invalid, but the issue got fixed in 22w42a.
Duplicate of MC-112826, fixed in the snapshots.