Rename commit_changes to changes_in_commit and use one commit as …

…input only.

That way we double-down on diffing against the first parent only.

apps/desktop/src/lib/worktree/worktreeService.svelte.ts

@@ -44,7 +44,7 @@ function injectEndpoints(api: ClientState['backendApi']) {
 			 * entity entity adapter to create the necessary selectors.
 			 */
 			getChanges: build.query<EntityState<TreeChange, string>, { projectId: string }>({
-				query: ({ projectId }) => ({ command: 'worktree_changes', params: { projectId } }),
+				query: ({ projectId }) => ({ command: 'changes_in_worktree', params: { projectId } }),
 				/** Invalidating tags causes data to be refreshed. */
 				providesTags: [ReduxTag.WorktreeChanges],
 				/**

crates/but-core/src/diff/ui.rs

@@ -1,4 +1,5 @@
 use crate::ui::{TreeChange, WorktreeChanges};
+use gix::prelude::ObjectIdExt;
 use std::path::PathBuf;
 
 /// See [`super::worktree_changes()`].
@@ -10,10 +11,16 @@ pub fn worktree_changes_by_worktree_dir(worktree_dir: PathBuf) -> anyhow::Result
 /// See [`super::commit_changes()`].
 pub fn commit_changes_by_worktree_dir(
     worktree_dir: PathBuf,
-    old_commit_id: Option<gix::ObjectId>,
-    new_commit_id: gix::ObjectId,
+    commit_id: gix::ObjectId,
 ) -> anyhow::Result<Vec<TreeChange>> {
     let repo = gix::open(worktree_dir)?;
-    super::commit_changes(&repo, old_commit_id, new_commit_id)
+    let parent_id = commit_id
+        .attach(&repo)
+        .object()?
+        .into_commit()
+        .parent_ids()
+        .map(|id| id.detach())
+        .next();
+    super::commit_changes(&repo, parent_id, commit_id)
         .map(|c| c.into_iter().map(Into::into).collect())
 }

crates/but-core/tests/core/diff/ui.rs

@@ -376,7 +376,6 @@ fn commit_to_commit() -> anyhow::Result<()> {
     let actual =
         serde_json::to_string_pretty(&but_core::diff::ui::commit_changes_by_worktree_dir(
             worktree_dir,
-            Some(repo.rev_parse_single("@~1")?.into()),
             repo.rev_parse_single("@")?.into(),
         )?)?;
     insta::assert_snapshot!(actual, @r#"

crates/gitbutler-tauri/src/diff.rs

@@ -24,19 +24,14 @@ pub fn tree_change_diffs(
 
 #[tauri::command(async)]
 #[instrument(skip(projects), err(Debug))]
-pub fn commit_changes(
+pub fn changes_in_commit(
     projects: tauri::State<'_, gitbutler_project::Controller>,
     project_id: ProjectId,
-    old_commit_id: Option<HexHash>,
-    new_commit_id: HexHash,
+    commit_id: HexHash,
 ) -> anyhow::Result<Vec<TreeChange>, Error> {
     let project = projects.get(project_id)?;
-    but_core::diff::ui::commit_changes_by_worktree_dir(
-        project.path,
-        old_commit_id.map(Into::into),
-        new_commit_id.into(),
-    )
-    .map_err(Into::into)
+    but_core::diff::ui::commit_changes_by_worktree_dir(project.path, commit_id.into())
+        .map_err(Into::into)
 }
 
 /// This UI-version of [`but_core::diff::worktree_changes()`] simplifies the `git status` information for display in
@@ -50,7 +45,7 @@ pub fn commit_changes(
 /// All ignored status changes are also provided so they can be displayed separately.
 #[tauri::command(async)]
 #[instrument(skip(projects), err(Debug))]
-pub fn worktree_changes(
+pub fn changes_in_worktree(
     projects: tauri::State<'_, gitbutler_project::Controller>,
     project_id: ProjectId,
 ) -> anyhow::Result<WorktreeChanges, Error> {

crates/gitbutler-tauri/src/main.rs

@@ -271,8 +271,8 @@ fn main() {
                     workspace::hunk_dependencies_for_workspace_changes,
                     workspace::create_commit_from_worktree_changes,
                     workspace::amend_commit_from_worktree_changes,
-                    diff::worktree_changes,
-                    diff::commit_changes,
+                    diff::changes_in_worktree,
+                    diff::changes_in_commit,
                     diff::tree_change_diffs,
                     // `env_vars` is only supposed to be avaialble in debug mode, not in production.
                     #[cfg(debug_assertions)]