CTRL / CMD key get stuck on OS X / Text Box Backspace deletes whole word or whole line on Mac and Linux

This is not a duplicate of MC-886. Opening GUIs (including chat) clears the state of most keys, but does not clear the state of the control key.
To reproduce the problem:

1. Open a GUI to free your mouse

2. Hold CTRL

3. Click on another window to make Minecraft lose focus

4. Release control

5. Go back to Minecraft and open chat

6. Type a multi-letter word

7. Press backspace

8. Observe that the whole word has been deleted

For completeness, I am using Ubuntu.

Reopened.

So.... is there a solution for this or not....

I have this issue on Mac OSX, with both 1.6 and the new snapshots.
Occasionally the chat returns to normal, if I repeatedly tab out of the game and back in. (as that seems to cause it for me)

Pressing backspace deletes an entire word of text instead of just one letter. I noticed that if I press the command key it switches to deleting one letter.

The is a major constant annoyance.

Minecraft 1.7.2
Mac OS X 10.6.8
Java 6

I can confirm, following Tavis' steps. That being said, I'm not sure this could be fixed, as the game would have to be constantly checking if the shift and ctrl keys have been released.

Is this still a concern in the current Minecraft version 1.7.4 / Launcher version 1.3.8 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Cannot reproduce this issue in 14w34b

This is reproducible as a bug? Is this not a hardware related issue with the keyboard itself? I cannot replicate this.
Or if this bug is specific to Ubuntu (whatever that is), maybe the title should clarify that?

I am able to reproduce this with Ubuntu. Others have confirmed it previously with OSX.

I cannot reproduce with Windows. Please update title to clarify this for others testing.

for me this also seems to appear if the cmd key gets stuck and I try to write the letter V the content of the clipboard gets copied into the text box

Easier reproducer on OSX: Command-Tab to switch to a different window. When you switch back to the Minecraft window any keystrokes behave as if the Command key were still depressed (thus V behaves like Command-V, backspace like Command-backspace, etc).

Workaround on OSX: If you tap Command once or twice the problem corrects and keystrokes behave normally.

Perhaps check for the state of modifiers when the Minecraft window regains focus? Normally I'd be happy to submit a patch but...

This just happened to me on Minecraft 1.8.5
OSX 10.9.5 Mavericks. 8 GB, 6750M video, i7
java version "1.7.0_21"
Java(TM) SE Runtime Environment (build 1.7.0_21-b12)
Java HotSpot(TM) 64-Bit Server VM (build 23.21-b01, mixed mode)
I was logged into a server also running MC 1.8.5 on Ubuntu 12, although I think it's got nothing to do with it.

It does seem to be related to Command-Tab and/or switching between Minecraft and other applications.

I encounter often this bug. It's very annoying.

@Christopher:
That workaround doesn't work for me 😞 (Mac OS X 10.10, java 8, MC 1.8.8)

1.8.8 presents this issue as well. When I type the "a" key, it highlights my sentence, and any further key stroke causes the sentence to be deleted. This also happens when I try to drop items using "Q". Instead of dropping one item, the whole stack is dropped.

This happens to me too when switching desktops to my minecraft window in fullscreen, the command key gets stuck until I tap it inside minecraft. (Mac OS X 10.10, Java 8), still an issue in 15w41b.

Just checking in to say that this bug makes me scream at my computer at least once or twice a day.

I'm guessing the Mac client is not exactly super high-priority now, if it ever was.

I think if any one of the Mojang devs tries to use the game on Mac for just one day, this bug would get fixed. It's truly infuriating for anyone doing MC dev of any kind, since that routinely requires alt-tabbing away, and then back to type a command. 99% of the time you end up having to re-type the whole command, after realizing you just spewed some gibberish into chat. It's maddening!

Just so people know, if this is occurring for you, press the command key a few times and it'll fix temporarily. It's super annoying for me too.

Can we PLEASE get an update on this? This bug has existed for a very long time and it's incredibly frustrating. It has resulted in hours of retyping messages. I agree that if any Mojang devs attempted to use the Mac version of this game (and used Command Tab app switching) they would fix this bug immediately.

Can we please get some attention to this!

Agreed. It's infuriating having to retype messages all day, especially commands when working with command blocks.

It's not listed, so confirming this still exists in 1.9 and 1.9.2.

Something to note is that when the command key is stuck, not only does backspace clear entire words, but "a" selects-all, "v" pastes, and "x" cuts whatever is selected. (until pressing the command key a few times)

I don't know if it's useful to speculate on the bugtracker like this, but it's my impression that low-level stuff like modifier keybinding is handled not by minecraft, but by something lower in the stack. Like when we had a bug to improve Chinese keyboard input methods in Minecraft chat (MC-2781), it turned out not to work with Macs (MC-91132), but according to comments there, this was something that had to be fixed by the LWJGL team. This issue could be similar. I know some of the Mojang team do use macs, so the assertion that they would fix it immediately is demonstrably false. It's possible that the fix is not that straightforward.

It'd be nice to get some feedback either way. I don't see this behavior from other Java apps, so I can't imagine how low-level it could be.

If Mojang uses Macs I am a little shocked this doesn't drive them crazy- I know I'd want to nail it down if it were me. So you could be right, that there's some reason it's very hard to fix, that would be both surprising and a little disappointing.

Any possibility for a response from the team? The provided work-around really doesn't help anything, as you can see the numerous examples of how annoying this is. Yes it's "fixable" but not until after you're already frustrated about it. I'd love to say after years of dealing with it I've trained myself to mash command every time I alt-command back to MC, but apparently it's just not sticking in my brain.

Still exists in 16w21b.

Still exists in 1.10

Confirmed for Mac OS X El Capitan, running Java 1.8 with Minecraft 1.10.2 (vanilla, no mods).

This has been an issue for far too long, and is incredibly frustrating. Whilst I've never personally encountered it on Linux, it was always a problem on OS X. I've also tried under macOS Sierra running Java 1.8, with the same result.

Confirmed for macOS Sierra 10.12.1
Running Java 1.8, with Minecraft 1.11 vanilla.

I can confirm this too, with the same setup as Simon Wermuth. Is this perhaps a macOS bug?

@unknown summary of this ticket:

...on Mac and Linux

Confirmed in 1.11.2.

This is so much worse now that command+digit saves hotbars in 17w06a. It was reported separately as MC-113915. It is really a duplicate of this one, but it alone is bigger than this used to be. Please expedite fixing.

Can confirm on `OS X 10.11.6 (15G1212)` MC 1.11.2 (Modded, Major Mods: MCForge, Optifine). Also is still reproducible after switching modifier keys, this can be accomplished by going to `System Preferences -> Keyboard -> Modifier Keys` and swapping the `Command Key` with another modifier key.

==EDIT==
After looking at Minecraft's source code (through the minecraft forge sdk) I have determined this: This is most likely a problem with LWJGL 2 or OSX, I do not know if updating to LWJGL 3 will fix this problem. The way that minecraft handles stuff like `Ctrl/Cmd + a` is as follows: Minecraft queries LWJGL to determine if the 'a' key is pressed, then it ensures that the 'Shift' and 'Alt' keys are not pressed, then it checks if the 'Ctrl/Cmd` key is pressed this is done by checking the keycodes `219` (L_META/L_CMD) and `220` (R_META/R_CMD) if minecraft is running on OSX, on Windows it checks for keycodes `29` (L_CTRL) and `157` (R_CTRL). Minecraft does all of these checks by using the method `org.lwjgl.input.Keyboard#isKeyDown(int)`. LWJGL 3 uses GLFW for keyboard input and I have not found any issues reporting the same problem on there github issue tracker. This possibly could be fixed by updating to LWJGL 3 or it could be an internal problem with OSX, this is not a problem with Java since all keyboard handling in both LWJGL 2 and GLFW is done natively (with C/C++ code).

==EDIT 2==
People have mentioned reproducibility on Linux so this is most likely a problem with LWJGL2. Possibly the Unix Kernel but OSX has modified the Kernel enough that it is probably not the case.

LWJGL has been implicated before. I think there's a mention out somewhere else that LWJGL 3 would fix it.

It certainly has nothing to do with the kernel. The kernels aren't even the same. What GNU/Linux and macOS share is a similar command line and POSIX-ish mid-level programming environment. Both higher and lower levels are fundamentally different. The relevant difference is in the UI APIs and how they're (ab)used by Minecraft and its libraries.

Whatever it is, it's extremely irritating.

Glad this was reopened. So annoying and makes the Minecraft chat almost unusable.

Fun new 1.12 side-feature: there must be some kind of key combination for the narrator, because it's constantly turning on for me as a result of this bug.

It really would be nice if this could get fixed.

Ah yes. The narrator turning itself on whenever I want to tab back into the game.

Giving a little more input: This must be related to LWJGL. It happened to me that there would be text in the chat box (when I switch tab out & in) which has been previously in memory (by another program) in an unused chunk of the memory (apparently the software did not dereference the string properly). Good news is: By using the command slash (one or multiple times) the bug usually disappears after a short amount of time.

TL;DR: Fixing stuck-on Command might also "fix" stuck-on right-click, which a lot of people rely upon heavily. Best not to create that much havoc over something fixed by remembering to tap Command an extra time.

Long version:

I would like to give a warning to those who are asking too vehemently for this bug to be fixed. This bug is annoying. No question there. But fixing it may have undesirable consequences for many.

For me, this meta key problem never became a huge nuisance until Command was chosen as the meta key for saving hotbars in creative mode. Every time I would switch from/to Minecraft, pressing a number key would wreck one of my saved toolbars. I had suggested using Option instead, but Mojang's choice of using C and X was all-around a much better solution. Now, the only times this is a problem is in chat and when I press Q, making throwing items vs. stacks inconsistent. And it's dealt with by trying to remember to just tap Command an extra time when returning to Minecraft.

This bug is caused by a bug in some library that Minecraft uses to process key input. I've written my own Java code to test this, and I find that if you Command-Tab away, the command key down event is delivered, but there's no key up even. Then when you command-tab back, the key up for Command event is delivered. For some reason that key up event is lost by this library, and I suspect it has something to do with a change of focus happening at the same time. I've spoken directly to Dinnerbone about this on IRC, and if I recall correctly, he said something about not having access to the source code to this library. So they'd have to rewrite it from scratch to fix the problem.

But let's say they fixed this problem. In fact, there are other keys that also get stuck on when there's a chance in focus. An important one is right-click. You can intentionally get right-click stuck on by holding it down and then pressing F11. People rely on this for things like AFK fishing farms and AFK sand sweepers for removing the water from around ocean monuments.

If Mojang were to go through the effort to fix this bug, then there's a distinct possibility that the F11/right-click trick would get "fixed" as well. A lot of people (including possibly some devs at Mojang) are somewhat antagonistic to AFK fishing, because they consider it overpowered. I'm sure there's an app you can install that will spoof keys to applications of your choice, but do you really want to go to that trouble?

Now, I personally would be happy to volunteer to rewrite this module from scratch. All I need to know is the API, and I could probably write a drop-in replacement. It depends on how much platform-specific issues I'd have to deal with, which could balloon the development time. I would release it under an MIT or Apache license or whatever people want. One of the problems here is that Mojang seems to have some massive fear of accepting code from outsiders, even bug fixes and from people begging them to take the code with no strings attached. I really don't understand what makes them tick.