hunk context lines are computed against the correct head

gitbutler-app/src/git/show.rs

@@ -4,23 +4,6 @@ use std::{path, str};
 
 use super::Result;
 
-pub fn show_file_at_head<P: AsRef<path::Path>>(
-    repository: &Repository,
-    file_path: P,
-) -> Result<String> {
-    let file_path = file_path.as_ref();
-    let head_tree = repository.head()?.peel_to_commit()?.tree()?;
-    match head_tree.get_path(file_path) {
-        Ok(tree_entry) => {
-            let blob = repository.find_blob(tree_entry.id())?;
-            let content = str::from_utf8(blob.content())?;
-            Ok(content.to_string())
-        }
-        // If a file is new, it's content at HEAD is the empty string
-        Err(_) => Ok(String::new()),
-    }
-}
-
 pub fn show_file_at_tree<P: AsRef<path::Path>>(
     repository: &Repository,
     file_path: P,

gitbutler-app/src/virtual_branches/virtual.rs

@@ -20,7 +20,9 @@ use crate::{
 
 use super::{
     branch::{self, Branch, BranchCreateRequest, BranchId, FileOwnership, Hunk, Ownership},
-    branch_to_remote_branch, context, errors, target, Iterator, RemoteBranch,
+    branch_to_remote_branch, context, errors,
+    target::{self, Target},
+    Iterator, RemoteBranch,
 };
 
 type AppliedStatuses = Vec<(branch::Branch, HashMap<path::PathBuf, Vec<diff::Hunk>>)>;
@@ -57,6 +59,7 @@ pub struct VirtualBranch {
     pub ownership: Ownership,
     pub updated_at: u128,
     pub selected_for_changes: bool,
+    pub head: git::Oid,
 }
 
 // this is the struct that maps to the view `Commit` type in Typescript
@@ -874,15 +877,20 @@ pub fn list_virtual_branches(
             ownership: branch.ownership.clone(),
             updated_at: branch.updated_timestamp_ms,
             selected_for_changes: branch.selected_for_changes == Some(max_selected_for_changes),
+            head: branch.head,
         };
         branches.push(branch);
     }
 
     let mut branches = branches_with_hunk_locks(branches, project_repository)?;
     for branch in &mut branches {
-        branch.files =
+        branch.files = files_with_hunk_context(
-            files_with_hunk_context(&project_repository.git_repository, branch.files.clone(), 3)
+            &project_repository.git_repository,
-                .context("failed to add hunk context")?;
+            branch.files.clone(),
+            3,
+            branch.head,
+        )
+        .context("failed to add hunk context")?;
     }
 
     branches.sort_by(|a, b| a.order.cmp(&b.order));
@@ -947,14 +955,18 @@ fn files_with_hunk_context(
     repository: &git::Repository,
     mut files: Vec<VirtualBranchFile>,
     context_lines: usize,
+    branch_head: git::Oid,
 ) -> Result<Vec<VirtualBranchFile>> {
     for file in &mut files {
         if file.binary {
             continue;
         }
         // Get file content as it looked before the diffs
-        let file_content_before = show::show_file_at_head(repository, file.path.clone())
+        let branch_head_commit = repository.find_commit(branch_head)?;
-            .context("failed to get file contents at HEAD")?;
+        let head_tree = branch_head_commit.tree()?;
+        let file_content_before =
+            show::show_file_at_tree(repository, file.path.clone(), &head_tree)
+                .context("failed to get file contents at base")?;
         let file_lines_before = file_content_before.split('\n').collect::<Vec<_>>();
 
         // Update each hunk with contex lines before & after