Open Bug 1354359 Opened 4 years ago Updated 2 years ago

Combination of undo and redo can irrecoverably delete swathes of text


(Core :: DOM: Editor, defect, P3)

52 Branch





(Reporter: najoll, Unassigned)



User Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:52.0) Gecko/20100101 Firefox/52.0
Build ID: 20170323105023

Steps to reproduce:

I can't easily reproduce the bug, but the problem occured just now and it has happened to me in the past. I typed text, deleted some, then performed a combination of undo and redo - the exact combination is what I can't recall or reproduce.

Actual results:

Painstakingly crafted paragraphs of text were lost forever.

Expected results:

Some combination of undo and redo should have recovered my text. Or at least a draft of the message should have contained it. (I have autosave set to save a draft every two minutes.)
I am going to add the following here. (I add it here, rather than append it to some bug reports of mine which are perhaps more relevant, because, for reasons to do with login problems, I can't locate my previous bugs.)

The combination of problems that I have reported recently - to do with deleting HTML formatting, fonts changing when I don't want them to and the impossibility of turning them back, and tabing - mean that writing professional-looking e-mails in Thunderbird is more or less impossible. (And there are other problems too.) I am looking for a new e-mail client.
Your other bug reports at

I don't think it will make a difference but can't totally predict... does same thing in safe mode?
If works in safe mode, please determine which addon is at fault, post the name here, and notify the author of the addon
Flags: needinfo?(najoll)
You're lucky if undo works, no warranty at all for redo :-(
Component: Untriaged → Editor
Product: Thunderbird → Core
I've discovered the, or at least a, source of the problem. And the problem doesn't seem related to extensions, although it may be slightly intermittent. Do the following.

(1) Copy the text below and paste it into a new blank email.

	The Hitch Hiker’s Guide to the Galaxy has, in what we laughingly call the past, had a great deal to say on the subject of parallel universes. Very little of this is, however, at all comprehensible to anyone below the level of Advanced God, and since it is now well-established that all known gods came into existence a good three millionths of a second after the Universe began rather than, as they usually claimed, the previous week, they already have a great deal of explaining to do as it is, and are therefore not available for comment on matters of deep physics at this time.
	One encouraging thing the Guide does have to say on the subject of parallel universes is that you don’t stand the remotest chance of understanding it. You can therefore say `What?’ and `Eh?’ and even go cross-eyed and start to blither if you like without any fear of making a fool of yourself.
	The first thing to realise about parallel universes, the Guide says, is that they are not parallel.
	It is also important to realise that they are not, strictly speaking, universes either, but it is easiest if you try and realise that a little later, after you’ve realised that everything you’ve realised up to that moment is not true.
	The reason they are not universes is that any given universe is not actually a thing as such, but is just a way of looking at what is technically known as the WSOGMM, or Whole Sort of General Mish Mash. The Whole Sort of General Mish Mash doesn’t actually exist either, but is just the sum total of all the different ways there would be of looking at it if it did.
	The reason they are not parallel is the same reason that the sea is not parallel. It doesn’t mean anything. You can slice the Whole Sort of General Mish Mash any way you like and you will generally come up with something that someone will call home.
	Please feel free to blither now.
	The Earth with which we are here concerned, because of its particular orientation in the Whole Sort of General Mish Mash, was hit by a neutrino that other Earths were not. ¶ This neutrino struck an atom. [. . . .] ¶ The atom was part of a molecule. The molecule was part of a nucleic acid. The nucleic acid was part of a gene. The gene was part of a genetic recipe for growing . . . and so on. ¶ The upshot was that a plant ended up growing an extra leaf. In Essex. Or what would, after a lot of palaver and local difficulties of a geological nature, become Essex.
	The plant was a clover. It threw its weight, or rather its seed, around extremely effectively and rapidly became the world's dominant type of clover. The precise causal connection between this tiny biological happenstance, and a few other minor variations that exist in that slice of the Whole Sort of General Mish Mash – such as Tricia McMillan failing to leave with Zaphod Beeblebrox, abnormally low sales of pecan-flavoured ice-cream and the fact that the Earth on which all this occurred did not get demolished by the Vogons to make way for a new hyperspace bypass – is currently sitting at number 4,763,984,132 on the research project priority list at what was once the History Department of the University of MaxiMegalon, and no one currently at the prayer meeting by the poolside appears to feel any sense of urgency about the problem.
Douglas Adams, Mostly Harmless, ch. 3. Numbering added.

(2) Press CTRL-Z.

(3) Press CTRL-Z again.

(4) Have fun trying to recover your text via CTRL-Y. Repeat 1-3 a few times if you find that you *can* recover your text. My bet is that, after a few goes, you'll find you can't.

As to 'no warranty at all for redo': I'll just shoot myself now. Don't worry, I'll be humane.
Flags: needinfo?(najoll)
Priority: -- → P3
Duplicate of this bug: 1379260
This is still happening on Thunderbird 52.3 on Windows. It happened to me just now and I had no draft that I could restore (presumably because the time threshold - two-minutes, on my system; I've changed it to one - for saving drafts had not been reached). I cannot say I was pleased when my carefully crafted, long-ish e-mailed was vaporised.
Duplicate of this bug: 1428232
I just lost some more text. To wit: a multi-line last paragraph of an e-mail. Thunderbird 52.5.2, Windows 8 x64. I should be happy to try to give more information.
See Also: → 1433387
I am still losing text from my e-mails. I hate to bang on, but this seems important.

Cf. perhaps this open bug: 794173. I find the problem hard to reproduce. One reason for that is that the problem is intermittent or else depends on some particular steps that are hard to discern. There is also this: when the problem occurs - as it did just now, losing me, permanently, several lines of rather carefully composed text - I have to rewrite the e-mail that I wanted to send and hence I am not inclined instead to file a bug report, and, also, I cannot be expected to record all the steps I take whenever I compose an e-mail. But: have none of the developers ever experienced the problem?

I can confirm that bug still exist. Just lost whole written e-mail because of this bug. Very annoying.

This happens when pasting some formatted text from MS Word or similar program. Then wanting to undo to paste without formatting, but undo will delete all previous text as well with no way to redo.

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