Unexpected tool behavior on 'crumbly' nodes

[Terumoc]

Hello!

I'm working on a mod that provides information about the node you're clicking, and that includes the fitness of your current tool in mining it it.

So far I think I've done a pretty good job in figuring out the default minetest digging system, where:
1. The current tool must have a group that matches the node's
2. The current tool must have a dig speed for the nodes "hardness" (ex: NodeDef->groups.cracky=3 needs a ToolDef->groupcaps.times.cracky[3] to exist for that tool to work)
3. The node cannot have a level group higher than the tool's matching maxlevel (ergo, NodeDef->groups.level must be <= ToolDef->groupcaps.times.cracky.maxlevel)

However, I've realized that dirt nodes of all types, gravel, and sand (so nearly every other crumbly node I've tested) can be dug with tools that do not have a crumbly group such as picks, axes, and swords. Because of this, my mod isn't reporting those tools correctly

Can anyone with more experience or knowledge of minetest's internals help me out in figuring out why crumbly-group nodes can be dug by tools without a crumbly group set? Is it just some sort of default override behavior to allow anything to mine crumbly nodes? I'd really like to know the reason this happens so I can account for it accurately in my mod.

Oh and the mod is on github at https://github.com/Terumoc/teruview if you want to see it.

Thanks a lot!

[sofar]

https://wiki.minetest.net/Hand

Even while wielding a tool that is incapable of digging a specific node type, you are also in the possession of the "hand" item. In most games, the hand is capable of removing a bunch of nodes that e.g. a pickaxe isn't capable of. If the pickaxe fails to dig a node, the hand tool capabilities will be used.

https://github.com/minetest/minetest_ga ... it.lua#L28

[Terumoc]

Aha! That definitely explains it. It's a good idea too, I like that it's implemented that way.

Thanks a ton for the explanation!