jj resolve panics when resolving conflicts involving deleted files #6250
Description
Description
jj resolve panics whenever resolving a conflict involving deleted files using an external merge tool (or :ours or :theirs).
This was found by saber on Discord for :ours and :theirs, but I tested it and the same issue occurs with external merge tools as well.
Steps to Reproduce the Problem
- Create a modify-delete conflict (
2-sided conflict including 1 deletion). - Run
jj resolvewith an external merge tool (or with:oursor:theirs). - Resolve the conflict using the merge tool.
Expected Behavior
The resolution of the conflict is saved in the working copy. Due to executable bit handling, it may not be possible to resolve the conflict fully, but at least it shouldn't panic. Alternatively, we could just disallow jj resolve when one of the sides is a deletion.
Actual Behavior
A panic like this when the resolution doesn't delete the file (which is normally the case for external merge tools):
thread 'main' panicked at lib/src/merge.rs:626:21:
assertion failed: file_id.is_none()
stack backtrace:
0: __rustc::rust_begin_unwind
1: core::panicking::panic_fmt
2: core::panicking::panic
3: jj_lib::merge::Merge<core::option::Option<T>>::with_new_file_ids::{{closure}}
4: <core::iter::adapters::map::Map<I,F> as core::iter::traits::iterator::Iterator>::next
5: <smallvec::SmallVec<A> as core::iter::traits::collect::Extend<<A as smallvec::Array>::Item>>::extend
6: <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter
7: core::iter::traits::iterator::Iterator::collect
8: jj_lib::merge::Merge<core::option::Option<T>>::with_new_file_ids
9: jj_cli::merge_tools::external::run_mergetool_external_single_file
10: jj_cli::merge_tools::external::run_mergetool_external
11: jj_cli::merge_tools::MergeEditor::edit_files
12: jj_cli::commands::resolve::cmd_resolve
Otherwise, a panic like this when the resolution deletes the file (which may be the case for :ours or :theirs):
thread 'main' panicked at lib/src/merge.rs:621:46:
called `Option::unwrap()` on a `None` value
stack backtrace:
0: __rustc::rust_begin_unwind
1: core::panicking::panic_fmt
2: core::panicking::panic
3: core::option::unwrap_failed
4: jj_lib::merge::Merge<core::option::Option<T>>::with_new_file_ids::{{closure}}
5: <core::iter::adapters::map::Map<I,F> as core::iter::traits::iterator::Iterator>::next
6: <smallvec::SmallVec<A> as core::iter::traits::collect::Extend<<A as smallvec::Array>::Item>>::extend
7: <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter
8: core::iter::traits::iterator::Iterator::collect
9: jj_lib::merge::Merge<core::option::Option<T>>::with_new_file_ids
10: jj_cli::merge_tools::pick_conflict_side
11: jj_cli::merge_tools::MergeEditor::edit_files
12: jj_cli::commands::resolve::cmd_resolve
Specifications
- Platform: NixOS
- Version:
jj 0.28.0-29f24ad2d8746e497abb701a99ba00b874f0cea7