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### Problem description
<!-- Describe the bug that you fixed/feature request that you
implemented, or link to an existing issue describing it -->
Fixed possible bug of `EventManager::unsubscribe`
`std::map` only allows unique key, but the same token can subscribe to
multiple events.
1a2a926b77/lib/libimhex/include/hex/api/event.hpp (L104-L107)
If the previous token has already subscribed to an event, then when
subscribing again, `getTokenStore().insert` will not do anything
(Because its type is `std::map`)
1a2a926b77/lib/libimhex/include/hex/api/event.hpp (L122-L134)
At this point in `unsubscribe`, the `iter` may not be able to find the
correct event and erase it
### Implementation description
<!-- Explain what you did to correct the problem -->
Change `tokenStore` to `std::multimap` instead of `std::map`, which
cannot unsubscribe multiple events correctly
### Screenshots
<!-- If your change is visual, take a screenshot showing it. Ideally,
make before/after sceenshots -->
### Additional things
<!-- Anything else you would like to say -->
As discussed (many times) on Discord, does the same as the new favorite
tag, but instead allows you to add multiple groups.
Initially, this would cause some insane issues with draw/reset
(apparantly) fighting eachother in the pattern drawer. After a lot of
trial and error, I decided to rewrite the flow that is responsible for
calling reset. Now evaluating patterns is the one to decide when the
reset happens, not the core "game"-loop.
To make sure that draw and reset can never happen at the same time, the
mutex originally used for the favorites has been repurposed. Due to the
restructuring, the mutex in the favorite-task is no longer needed, as
that will only ever kick-off after reset is called and if there are
actually patterns, which can never line up to be accessed on different
threads at the same time.
Last but not least, I noticed that hard crashes could result in your
config file getting overridden. I added a check to prevent that.
Last I issue I can see is that if you use an excessive amount of
favorites/groups, a crash can still happen, but it only happens when you
close the program (occasionally, but unpredictable). Before, this would
happen if you ran the evaluation a second time. I boiled the cause of
the crash down to these lines of code in evaluator.cpp >
patternDestroyed:
```cpp
if (pattern->isPatternLocal()) {
if (auto it = this->m_patternLocalStorage.find(pattern->getHeapAddress()); it != this->m_patternLocalStorage.end()) {
auto &[key, data] = *it;
data.referenceCount--;
if (data.referenceCount == 0)
this->m_patternLocalStorage.erase(it);
} else if (!this->m_evaluated) {
err::E0001.throwError(fmt::format("Double free of variable named '{}'.", pattern->getVariableName()));
}
}
```
Specifically, trying to access the `*it` is the reason for the crash
(this was also the cause of the crashes before my fixes, but then during
evaluation).
I'm suspecting the root cause is somewhere in the `.clone` methods of
the patterns. I'd say that for now a crash when closing the program is
more acceptable than during evaluation (which can even happen if you use
favorites).
This PR fixes some things about crash handling:
- when the terminate handler is called, immediately set it back to the
original one, so can't make a recursion if the crash-handling code fails
- Only save projects if the crash occured after Imhex finished startup
- do not update the project location when saving the crash backup file:
this will remove problems when `EventAbnormalTermination` is called
before `crashCallback()`
I also added a bit more documentation
In order to do this I add to make some other additions :
- Add a warning popup (TODO, maybe add some icons to differentiate
error/warning popups in a future PR ?)
- create showError() and showWarning() functions, as helpers to show a
message both to the logs and as a popup
