[MC-4239] Redstone and string in a cobble generator turn into obsidian

In a normal cobblestone generator, placing redstone in the place of where the cobble would normally be generated, obsidian is generated instead.

Today I've looked in the code (no mention of redstone being a special case) and tested around to see that string (with a single hook placed to the south or west) also works.

For a long time I thought this was either a little secret feature or a bug that's been accepted as a feature, so using redstone to not waste lava source blocks was always something I've accepted and used since I knew of this, maybe even up to a year back. For me it was never a problem, except that now with string, it makes it officially a bug. It worries me though, I wouldn't want to lose the ability of making an obsidian generator using redstone, so I hope that'll get put back into as a feature.

Linked issues

is duplicated by 2

MC-58365 Obsidian generators do not work Resolved

MC-59811 obsidian generator's dont work Resolved

relates to 2

MC-64506 Obsidian generators do not work Resolved

MC-11400 Powered redstone can't be converted into obsidian farm Resolved

Comments 14

Cody 2012-12-08T02:54:53Z

This is not a bug, this is a feature that has been in since way back, at least beta 1.4. Obsidian is not hard to get any more.

Dean Baset 2012-12-08T03:05:57Z

@Cody just because it is from a long time ago doesn't mean it's not a bug. It's like saying that chunk errors aren't a bug because they have been around since infdev.

Tails 2012-12-08T03:08:02Z

Confirmed. Also obsidian is renewable since the introduction of nether portals, see MC-1314.

Yoann Petremann 2013-03-09T11:21:53Z

Please mark as "Work as intended"

Sven Braune 2013-03-09T12:22:35Z

Why mark this as works as intended?

4 more comments

Torabi 2013-03-09T15:25:13Z

Notch posted about this on reddit about a year ago. He confirmed that it was a bug, decided to leave it alone for the time being because people liked it, but warned that he might decide to fix it later. Mojang's bugfixing strategy hasn't changed, as far as I can tell. Bugs people like are generally left alone, unless they cause problems or get in the way of fixing some other, undesirable behavior. However, that doesn't mean they've given up the right to decide to fix bugs even if people like them. It's still their game, and the solutions they provide are usually better than the original buggy behavior people got used to.

As it is, obsidian is renewable. Even without exploiting the extra blocks nether portals make, the nether is practically infinite, and full of lava. It's not that the quantity of obsidian that can be created is very limited, it's about the danger in acquiring it.

I could see this being declared a feature, since there's some level of logic to it (flowing lava + redstone = molten redstone, molten redstone + water = obsidian), and that could be expanded upon, made into interesting gameplay, but string is a lot harder to swallow.

Ezekiel 2014-01-29T16:58:03Z

Is this still a concern in the latest Minecraft version 14w04b? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Sven Braune 2014-01-29T17:45:14Z

Tested. This is still the case in snapshot 14w04b.

Anomie X 2014-06-22T11:47:38Z

This bug appears to have been fixed in 14w25a; it looks to me like the fix was a side effect of changes for the new block metadata format.

Since it doesn't seem anyone has explained the bug yet: The bug was because the lava flowing process looked something like this:
1. The flowing lava calls the function to replace the redstone block with flowing lava (block ID "flowing_lava", metadata value somewhere between 1 and 7).
2. The "replace block" function sets the block ID in the world with Lava, but does not update the block metadata yet.
3. The "replace block" function calls a method on the old block type, so it can react to the replacement.
4. The "replace block" function, if the call from step 3 didn't change the block ID again, updates the block metadata.

Certain blocks will do a "block tick" on adjacent blocks in step 3; among other things, redstone does this to update the power state. And the block tick handler for flowing lava checks if there is water adjacent and the block metadata value is 0 (meaning a source block), and if so replaces the lava with obsidian.

Null 2014-06-22T14:41:00Z

I did tests on 14w25b. Again, obsidian generators do not work in this version.
I add screenshots in:
https://bugs.mojang.com/browse/MC-58365

kumasasa 2014-06-22T15:35:15Z

. obsidian generators do not work in this version.

Therefore this ticket is resolved as fixed. Obsidian generators were a bug.

Null 2014-06-22T17:06:41Z

Mojang said it was "lucky bug transformed to feature"... Indeed, the obsidian generators were not working in v1.7.2 but v1.7.5 works... Why happened that? Because it's a feature.
Players and mobs do not die from great heights in shallow water YES it is bug for many versions and it was not removed yet. NO reports of first, second YES.
Remove obsidian generators is unfair... At least, should work only with redstone (and not web).

Anomie X 2014-06-22T18:51:11Z

> the obsidian generators were not working in v1.7.2

False.

Null 2014-06-23T00:21:58Z

Some forms of the generator does not work in others do. I'm sure because I tried it and because I made a map of adventures using the generator does not work in 1.7.2 but works in 1.7.5. You're not so sure ... You've done enough to help remove the generator . . . . . . .