jesseduffield.lazygit/pkg
Jesse Duffield bd7fabef1f Reduce the chance of race condition with list cursor
Before this commit, we had pkg/integration/tests/submodule/add.go
failing with a panic. I'm pretty sure the issue is this: we're now
calling quite a few GetDisabledReason calls on each layout() call,
and if a background thread happens to update a model slice while
we're doing this, we can end up with a selection index that's now
out of bounds because it hasn't been clamped to match the new list
length.

Specifically, here we had the selected index being -1 (the list starts
empty and somehow the value is -1 in this case) and then the list
gets a new submodule so the length is now 1, but the list cursor
doesn't know about this so remains on the old value. Then we confirm
the length is greater than zero and try to get the selected submodule
and get an out of bounds error.

This commit fixes the issue by clamping the selected index whenever
we get the length of the list so that it stays in-sync. This is not
a perfect solution because the length can change at any time, but
it seems to reliably fix the test, and using mutexes didn't seem to
make a difference.

Note that we're swapping the order of IFileTree and IListCursor in
the file tree view model to ensure that the list cursor's Len()
method is called (which performs the clamping).

Also, comment from the PR:
This 'trait' pattern we're using is convenient but can lead to awkward
situations. In this case we have both the list view model and the
(embedded) list cursor with a Len() method. The list cursor Len()
method just calls the list view model Len() method. But I wanted
to make it that the list view model now calls ClampSelection() on the
list cursor whenever it obtains the length. This will cause an
infinite loop because ClampSelection() internally calls Len()
(which calls the list view model's Len() method which in turn
calls ClampSelection() again, etc).

The only reason we were passing the list view model into the list
cursor was to supply the length method, so now we're just doing
that directly, and letting the list view model delegate the Len()
call to the list cursor, which now itself calls ClampSelection.
2024-01-28 09:20:52 +11:00
..
app Support range select in rebase actions 2024-01-23 17:23:56 +11:00
cheatsheet Render keybinding cheatsheet as markdown table 2024-01-28 08:12:01 +11:00
commands Show mode-specific keybinding suggestions 2024-01-28 08:33:13 +11:00
common Add AppState to common.Common 2023-09-04 17:48:39 +02:00
config Add config setting to suppress showing file icons 2024-01-22 08:40:03 +01:00
constants Improve keybinding descriptions 2024-01-28 08:12:01 +11:00
env Support bare worktrees where worktree does not have its own .git file 2023-08-07 22:40:53 +10:00
fakes cleanup integration test code 2023-02-26 12:54:13 +11:00
gui Reduce the chance of race condition with list cursor 2024-01-28 09:20:52 +11:00
i18n Improve keybinding descriptions 2024-01-28 08:12:01 +11:00
integration Show mode-specific keybinding suggestions 2024-01-28 08:33:13 +11:00
jsonschema Add UserConfig jsonschema generation script 2023-12-02 10:46:24 +01:00
logs Remove secureexec package 2023-07-30 19:59:51 +10:00
snake integrate snake game into lazygit 2022-12-30 12:18:59 +11:00
tasks Refactor repo_paths.go to use git rev-parse 2024-01-24 08:40:01 +01:00
theme Standardise display of range selection across views 2024-01-19 10:47:21 +11:00
updates Construct arg vector manually rather than parse string 2023-05-23 19:49:19 +10:00
utils Rename MinMax to SortRange 2024-01-26 11:18:06 +01:00