project_panel: Fix crash when adding a new file or directory to the first folded directory (#23217)
tims
created
Closes #23216
This crash happens in the `update_visible_entries` function, where we
calculate `ancestors` and `current_ancestor_depth`. `ancestors` is map
storing information about folded ancestors and `current_ancestor_depth`
is basically selected ancestor index in reverse order of visibility.
For example, before adding a new file or directory in `a/b/c`, the
`ancestors` might look like:
```jsonc
{
"entry_id_of_c": {
"current_ancestor_depth": 2, // "a" is selected
"ancestors": ["entry_id_of_a", "entry_id_of_b", "entry_id_of_c"]
}
}
```
When new file or directory is added to`a`, ancestors length is reduced,
as `a` now is not part of folded dir due to having multiple children.
But depth still remains the same as while calculating it, we use depth
from `old_ancestors` to preserve selection across renders. This causes
panic.
```jsonc
{
"entry_id_of_c": {
"current_ancestor_depth": 2, // wrong: use of old depth here causes panic
"ancestors": ["entry_id_of_b", "entry_id_of_c"] // correct: notice "a" is missing, as "a" now has multiple children
}
}
```
This PR fixes it by capping depth so it don't exceed `ancestors` array.
This preserves existing depth as well as handles our edge case.
Release Notes:
- Fixed crash when adding a new file or directory to the first folded
directory