10 ms·

Well, I do think the thundebird team should investigate and fix this. But it is almost impossible to fix a bug you can't reproduce and have no clue why it might

by jraph 1y ago

Well, I do think the thundebird team should investigate and fix this. But it is almost impossible to fix a bug you can't reproduce and have no clue why it might be happening.

brookst 1y ago
if (!user_requested_mass_delete && delete_requests_past_second > 10) throw(“we sure seem to be deleting a lot of stuff from the server”)
- jraph 1y ago
  I would not want my email client to be relying on such brittle and incorrect heuristics. A better workaround would be to keep deleted emails around for some time so users have the option to restore them if the bug triggers. But this has drawbacks such as potential privacy breakage (you meant to delete mails you don't want the chance that anybody sees it) or free disk space management (your local drive is overloaded and you want to urgently free up space) or ux confusion (this is a de facto trash but Thunderbird already has such a feature) Ultimately, what needs to be done is make the code robust, make sure there are no race conditions, etc.
  - jamespo 1y ago
    Just do a complete rewrite in rust, that will solve all the issues
    - tomrod 1y ago
      Honestly? It might.
      - dbalatero 1y ago
        Only by being a statistically different code base, unless you think this is a memory safety bug?
        huimang 1y ago
        Looking at the various issues reported in this thread, it honestly seems that burning the entire codebase and rewriting it would be the best choice. Bonus points for using a modern systems programming language.
        stefanka 1y ago
        Safety in rufst is not only about memory safety. It’s also about avoiding unpredictable behavior.
        _bent 1y ago
        reading through the report, it's not unlikely to be a race condition
    - mattl 1y ago
      Is whichever part of Mozilla that runs Thunderbird going to rehire the rust team now?
    - goku12 1y ago
      Except the bug was filed in 2008. Back then, Rust was Graydon Hoare's personal project that Mozilla wouldn't start funding until a year later. Rust was written in OCaml and the famed borrow checker wouldn't be in place until 2010. The first public release was v0.1 in 2012 and the first stable release 1.0 wouldn't happen till 2015. The language was very different back then with sigils, garbage collection and green threading as language features. So this bug was already bugging people when Rust was just an embryo that was still years away from birth. Now even if we neglect the timeline, Rust only guarantees memory safety. If TB is deleting mails on the server too, then the corruption is happening over IMAP connections as well. Does that sound like a memory safety bug to you? Perhaps it is. But how do we eliminate the possibility of a logical bug that Rust won't protect you against, when nobody has any clue even now? And all that aside, if you're going to rewrite it in Rust, you might as well start a new project in Rust instead of porting an old design that may potentially contain a language-agnostic logical Heisenbug. I'm not trying to be hostile here. I started using Rust in 2013 (I have 12 years of experience in a 10 year old language, and a bunch of repos that I can't compile anymore unless I compile the compiler from old commits somehow!). I wouldn't use C or C++ for any of these applications - I simply don't have enough competence to avoid the kind of bugs that Rust protects me from (despite being a hardware engineer with more knowledge about memory management than about type system theory). Despite all that, statements like this will only cause an unwanted backlash against Rust. Not that you're entirely wrong, but some people are so offended by such suggestions for reasons that are still under investigation, that they start a crusade against Rust [1]. [1] https://fosstodon.org/@goku12/114077011555069124 https://fosstodon.org/@goku12/114077011555069124
      - amendegree 1y ago
        The op is being facetious
        tareqak 1y ago
        Sometimes, treating a facetious/sarcastic request seriously helps disarm the facetiousness. Other times, it does not.
  - brookst 1y ago
    Well, would you rather have a brittle heuristic lose all of your mail? My point wasn’t that this is a great solution, just that it is very easy and almost certainly better than doing nothing for almost two decades.
    - jraph 1y ago
      > Well, would you rather have a brittle heuristic lose all of your mail? That's not what's happening. I wouldn't expect such an heuristic to be currently present. There is a bug, not something intentional. > almost certainly better than doing nothing No, because with such an heuristic, you add behavior that's difficult for the user to understand well and to work with. With such an heuristic, you will lose some mails and at some point the process stops in the middle. Which mails have you lost? What is "many" mails? 10? 100? What if my computer is fast and is deleting 100s of mails per seconds, losing all the mails anyway? What if it is slow and never triggers the heuristic? If the heuristic does trigger, you end up with a mixed situation where you still have lost some stuff, but not all, and it'll be impossible to understand which ones. It doesn't fix the issue (you still lose email), just makes it even more difficult to understand even for the devs when they inevitable need to track down related issues. You really don't want to willingly add mechanisms that feel like they are non-deterministic: they are hard to debug, and hard for the users to grasp. A way better solution is backups anyway: if you care not to lose your emails, you should be backing them up. From the beginning, your local TB mails are not a proper backup of your IMAP account because it's two-way synchronized so you need a backup somewhere else. A still better workaround is disabling the move to local folder feature and make people copy and then manually delete mails. Not saying your heuristic is not a good idea or clever (it is clever and could lead to further good ideas), just that after reflection, it should probably not be implemented. It barely starts to address the issue and adds complexity for everyone involved.
- guerillagorilla 1y ago
  A better approach might be to feed all of this into an LLM to have it figure it out. If it finds a bug and has a fix, reproducing it might be easier and a test could potentially be written. I don’t think LLMs are the answer to everything, but this would be a good test for newer generations of LLMs as they’re developed. Worst case- it deletes all of your emails, but that would’ve happen anyway, right? =)
thaumasiotes 1y ago
> But it is almost impossible to fix a bug you can't reproduce and have no clue why it might be happening. No, not at all. It's very easy. This bug involves taking an inappropriate action under corrupted conditions. You don't need to know how those conditions arose. All you have to do is check whether they currently obtain, and - if so - refrain from taking the inappropriate action. For this bug, that looks like this: 1. When we're executing a "move"... 2. Before deleting the original messages... 3. Check whether the copies are identical to the originals... 4. And if not, delete the copies instead of the originals. At this point, the bug can't occur. The "root cause" bug, where your buggy logic says that you copied a bunch of messages even though you didn't, can still occur, but it can no longer delete any messages.
- nativeit 1y ago
  So…do it. Sounds like it’d make a great case study that would get a person tons of attention and praise on HN, a real feather to put in one’s cap. Literally nothing stopping anyone in this thread from opening a PR with this reportedly “very easy” fix that’s eluded developers for nearly two decades, and is so terrible folks swear off Thunderbird forever because I guess for email very basic rules for backing up data don’t apply (or something?) and/or Gmail and Outlook are implicitly trustworthy?
  - mixmastamyk 1y ago
    Did a developer ever try? Reading the issue, found only one person asking for test cases and trying to close it.
    - thaumasiotes 1y ago
      One of the many comments on the issue notes that although the bug has reoccurred in every version of Windows, it might not get much attention from developers because it is catalogued as something specific to Windows XP. Nobody in the intervening nine years followed up by updating the bug's metadata, though. It's still "Windows XP only".
  - 1y ago
bachmeier 1y ago
You know what else they could do? They could disable a feature that deletes large volumes of email the user doesn't intend to delete.
- Tepix 1y ago
  Sometimes you want to delete a whole bunch of mails, don't you?
  - bachmeier 1y ago
    I've updated my comment for clarity. The bug (which I've never encountered in more than 20 years as a Thunderbird user) is that users move messages to a local email folder, but the messages are deleted from the server without actually downloading them. At a minimum they should disable that operation. The guy that originally reported it worked at Sun and lost hundreds of work messages as a result of this bug. AFAICT the user wouldn't be affected if they did a copy of the messages and then manually deleted them from the server folder after confirming the copy was successful.
- mattl 1y ago
  I don’t remember the last time I deleted an email. I’ve marked things as spam, archived things but not deleted in a long while.
  - tssva 1y ago
    I delete email everyday.
godelski 1y ago
> it is almost impossible to fix a bug you can't reproduce It's also impossible to mark a bug report as resolved if you can't reproduce it. You could have fixed the bug (especially since a lot of TB was rewritten) but if you can't reproduce the bug you wouldn't know it was solved only that people stopped reporting it. This is actually a common occurrence with long standing bugs.
account42 1y ago
Reproducing bugs is a luxury and not even close to required for analyzing and fixing issues. Even if the issue is external (hardware, antivirus, etc.), the code can be changed to be more defensive and only ever delete the original when the new data has been successfully written and verified.
- jraph 1y ago
  A luxury? Not even close to required? You are not afraid of words! I'm not looking forward to receive a bug report from you! Yeah, reproducing is not theoretically mathematically necessary. In theory you could prove your code is correct with formal methods¹. Now, nobody does this because it is impractical (borderline impossible), reproducing is in practice so useful as to be almost essential: - it lets you study how your code behave in the problematic case and identify what's causing the exact issue the user is seeing - it lets you check that your fix does indeed address the bug I have indeed already fixed trivial bugs without reproduction cases from a vague description of a bug because I'm intimately familiar with the code and it immediately rings a bell: the cause is immediately obvious. But that's not the usual case. > the code can be changed to be more defensive and only ever delete the original when the new data has been successfully written and verified. What if the code is already designed like this (and I sure do hope it is currently written like that, because that's almost common sense, if not the only sensible way of moving something) but somehow fails for some currently inexplicable reason? It smells race condition to me. In the case of the discussed bug, users have described a reproduction case that's not 100%. But someone will need to find a 100% reproduction case. Users, or devs. It will not be optional. You can't play a guessing game, attempt to fix the code and hope for the best. You might be able to actually fix the bug, but without much confidence. Best case, you'll be able to find a reproduction case after fixing the bug (that you'll probably use as a functional test), to prove you fixed the bug for this specific case you found. You'll not be 100% sure you addressed the user's case. A bug can hide another one, so you could find and fix a bug, but the issue is still present in the user's case. You can only be sure with their reproduction case. But I agree that it is hard to reproduce a race condition. ¹ which in practice applies to code of trivial size (static analysis), or consists in checking a model but not the actual implementation (model checking), or does apply useful checks but is not exhaustive and has false positives / negatives (static analysis), or does apply useful exhaustive checks but only on a limited number of executions (runtime verification, and we do have functional tests that serve a similar purpose in practice - and you'll actually need the reproduction case here so you have the right execution to check), or requires you to write your code in a specific language (stuff like coq) and you cross your fingers that this specific language's implementation is itself correct. In short: not applicable here.

by jraph 1y ago

Well, I do think the thundebird team should investigate and fix this. But it is almost impossible to fix a bug you can't reproduce and have no clue why it might be happening.

brookst 1y ago

if (!user_requested_mass_delete && delete_requests_past_second > 10) throw(“we sure seem to be deleting a lot of stuff from the server”)

jraph 1y ago
I would not want my email client to be relying on such brittle and incorrect heuristics. A better workaround would be to keep deleted emails around for some time so users have the option to restore them if the bug triggers. But this has drawbacks such as potential privacy breakage (you meant to delete mails you don't want the chance that anybody sees it) or free disk space management (your local drive is overloaded and you want to urgently free up space) or ux confusion (this is a de facto trash but Thunderbird already has such a feature) Ultimately, what needs to be done is make the code robust, make sure there are no race conditions, etc.
- jamespo 1y ago
  Just do a complete rewrite in rust, that will solve all the issues
  - tomrod 1y ago
    Honestly? It might.
    - dbalatero 1y ago
      Only by being a statistically different code base, unless you think this is a memory safety bug?
      - huimang 1y ago
        Looking at the various issues reported in this thread, it honestly seems that burning the entire codebase and rewriting it would be the best choice. Bonus points for using a modern systems programming language.
      - stefanka 1y ago
        Safety in rufst is not only about memory safety. It’s also about avoiding unpredictable behavior.
      - _bent 1y ago
        reading through the report, it's not unlikely to be a race condition
  - mattl 1y ago
    Is whichever part of Mozilla that runs Thunderbird going to rehire the rust team now?
  - goku12 1y ago
    Except the bug was filed in 2008. Back then, Rust was Graydon Hoare's personal project that Mozilla wouldn't start funding until a year later. Rust was written in OCaml and the famed borrow checker wouldn't be in place until 2010. The first public release was v0.1 in 2012 and the first stable release 1.0 wouldn't happen till 2015. The language was very different back then with sigils, garbage collection and green threading as language features. So this bug was already bugging people when Rust was just an embryo that was still years away from birth. Now even if we neglect the timeline, Rust only guarantees memory safety. If TB is deleting mails on the server too, then the corruption is happening over IMAP connections as well. Does that sound like a memory safety bug to you? Perhaps it is. But how do we eliminate the possibility of a logical bug that Rust won't protect you against, when nobody has any clue even now? And all that aside, if you're going to rewrite it in Rust, you might as well start a new project in Rust instead of porting an old design that may potentially contain a language-agnostic logical Heisenbug. I'm not trying to be hostile here. I started using Rust in 2013 (I have 12 years of experience in a 10 year old language, and a bunch of repos that I can't compile anymore unless I compile the compiler from old commits somehow!). I wouldn't use C or C++ for any of these applications - I simply don't have enough competence to avoid the kind of bugs that Rust protects me from (despite being a hardware engineer with more knowledge about memory management than about type system theory). Despite all that, statements like this will only cause an unwanted backlash against Rust. Not that you're entirely wrong, but some people are so offended by such suggestions for reasons that are still under investigation, that they start a crusade against Rust [1]. [1] https://fosstodon.org/@goku12/114077011555069124 https://fosstodon.org/@goku12/114077011555069124
    - amendegree 1y ago
      The op is being facetious
      - tareqak 1y ago
        Sometimes, treating a facetious/sarcastic request seriously helps disarm the facetiousness. Other times, it does not.
- brookst 1y ago
  Well, would you rather have a brittle heuristic lose all of your mail? My point wasn’t that this is a great solution, just that it is very easy and almost certainly better than doing nothing for almost two decades.
  - jraph 1y ago
    > Well, would you rather have a brittle heuristic lose all of your mail? That's not what's happening. I wouldn't expect such an heuristic to be currently present. There is a bug, not something intentional. > almost certainly better than doing nothing No, because with such an heuristic, you add behavior that's difficult for the user to understand well and to work with. With such an heuristic, you will lose some mails and at some point the process stops in the middle. Which mails have you lost? What is "many" mails? 10? 100? What if my computer is fast and is deleting 100s of mails per seconds, losing all the mails anyway? What if it is slow and never triggers the heuristic? If the heuristic does trigger, you end up with a mixed situation where you still have lost some stuff, but not all, and it'll be impossible to understand which ones. It doesn't fix the issue (you still lose email), just makes it even more difficult to understand even for the devs when they inevitable need to track down related issues. You really don't want to willingly add mechanisms that feel like they are non-deterministic: they are hard to debug, and hard for the users to grasp. A way better solution is backups anyway: if you care not to lose your emails, you should be backing them up. From the beginning, your local TB mails are not a proper backup of your IMAP account because it's two-way synchronized so you need a backup somewhere else. A still better workaround is disabling the move to local folder feature and make people copy and then manually delete mails. Not saying your heuristic is not a good idea or clever (it is clever and could lead to further good ideas), just that after reflection, it should probably not be implemented. It barely starts to address the issue and adds complexity for everyone involved.
guerillagorilla 1y ago
A better approach might be to feed all of this into an LLM to have it figure it out. If it finds a bug and has a fix, reproducing it might be easier and a test could potentially be written. I don’t think LLMs are the answer to everything, but this would be a good test for newer generations of LLMs as they’re developed. Worst case- it deletes all of your emails, but that would’ve happen anyway, right? =)

thaumasiotes 1y ago

> But it is almost impossible to fix a bug you can't reproduce and have no clue why it might be happening. No, not at all. It's very easy. This bug involves taking an inappropriate action under corrupted conditions. You don't need to know how those conditions arose. All you have to do is check whether they currently obtain, and - if so - refrain from taking the inappropriate action. For this bug, that looks like this: 1. When we're executing a "move"... 2. Before deleting the original messages... 3. Check whether the copies are identical to the originals... 4. And if not, delete the copies instead of the originals. At this point, the bug can't occur. The "root cause" bug, where your buggy logic says that you copied a bunch of messages even though you didn't, can still occur, but it can no longer delete any messages.

nativeit 1y ago
So…do it. Sounds like it’d make a great case study that would get a person tons of attention and praise on HN, a real feather to put in one’s cap. Literally nothing stopping anyone in this thread from opening a PR with this reportedly “very easy” fix that’s eluded developers for nearly two decades, and is so terrible folks swear off Thunderbird forever because I guess for email very basic rules for backing up data don’t apply (or something?) and/or Gmail and Outlook are implicitly trustworthy?
- mixmastamyk 1y ago
  Did a developer ever try? Reading the issue, found only one person asking for test cases and trying to close it.
  - thaumasiotes 1y ago
    One of the many comments on the issue notes that although the bug has reoccurred in every version of Windows, it might not get much attention from developers because it is catalogued as something specific to Windows XP. Nobody in the intervening nine years followed up by updating the bug's metadata, though. It's still "Windows XP only".
- 1y ago

bachmeier 1y ago

You know what else they could do? They could disable a feature that deletes large volumes of email the user doesn't intend to delete.

Tepix 1y ago
Sometimes you want to delete a whole bunch of mails, don't you?
- bachmeier 1y ago
  I've updated my comment for clarity. The bug (which I've never encountered in more than 20 years as a Thunderbird user) is that users move messages to a local email folder, but the messages are deleted from the server without actually downloading them. At a minimum they should disable that operation. The guy that originally reported it worked at Sun and lost hundreds of work messages as a result of this bug. AFAICT the user wouldn't be affected if they did a copy of the messages and then manually deleted them from the server folder after confirming the copy was successful.
mattl 1y ago
I don’t remember the last time I deleted an email. I’ve marked things as spam, archived things but not deleted in a long while.
- tssva 1y ago
  I delete email everyday.

godelski 1y ago

> it is almost impossible to fix a bug you can't reproduce It's also impossible to mark a bug report as resolved if you can't reproduce it. You could have fixed the bug (especially since a lot of TB was rewritten) but if you can't reproduce the bug you wouldn't know it was solved only that people stopped reporting it. This is actually a common occurrence with long standing bugs.

account42 1y ago

Reproducing bugs is a luxury and not even close to required for analyzing and fixing issues. Even if the issue is external (hardware, antivirus, etc.), the code can be changed to be more defensive and only ever delete the original when the new data has been successfully written and verified.

jraph 1y ago
A luxury? Not even close to required? You are not afraid of words! I'm not looking forward to receive a bug report from you! Yeah, reproducing is not theoretically mathematically necessary. In theory you could prove your code is correct with formal methods¹. Now, nobody does this because it is impractical (borderline impossible), reproducing is in practice so useful as to be almost essential: - it lets you study how your code behave in the problematic case and identify what's causing the exact issue the user is seeing - it lets you check that your fix does indeed address the bug I have indeed already fixed trivial bugs without reproduction cases from a vague description of a bug because I'm intimately familiar with the code and it immediately rings a bell: the cause is immediately obvious. But that's not the usual case. > the code can be changed to be more defensive and only ever delete the original when the new data has been successfully written and verified. What if the code is already designed like this (and I sure do hope it is currently written like that, because that's almost common sense, if not the only sensible way of moving something) but somehow fails for some currently inexplicable reason? It smells race condition to me. In the case of the discussed bug, users have described a reproduction case that's not 100%. But someone will need to find a 100% reproduction case. Users, or devs. It will not be optional. You can't play a guessing game, attempt to fix the code and hope for the best. You might be able to actually fix the bug, but without much confidence. Best case, you'll be able to find a reproduction case after fixing the bug (that you'll probably use as a functional test), to prove you fixed the bug for this specific case you found. You'll not be 100% sure you addressed the user's case. A bug can hide another one, so you could find and fix a bug, but the issue is still present in the user's case. You can only be sure with their reproduction case. But I agree that it is hard to reproduce a race condition. ¹ which in practice applies to code of trivial size (static analysis), or consists in checking a model but not the actual implementation (model checking), or does apply useful checks but is not exhaustive and has false positives / negatives (static analysis), or does apply useful exhaustive checks but only on a limited number of executions (runtime verification, and we do have functional tests that serve a similar purpose in practice - and you'll actually need the reproduction case here so you have the right execution to check), or requires you to write your code in a specific language (stuff like coq) and you cross your fingers that this specific language's implementation is itself correct. In short: not applicable here.