don't fail when computing diff on partial clones (#1093)

* Skip commit when computing diff if blob missing

* add integration test

* Assure that `changes()` don't track rewrites which accesses blobs; make filter=blob:none work.

We reproduce the issue by triggering rename detection, which means a change happens on top of a rename.
This tries to access blobs, and that doesn't always work.

It's a good idea to disable rewrite tracking and an oversight in the initial implementation, and one might
say it's tricky given that `gitoxide` automatically does what git does, which may be surprising sometimes
and be a hidden cost even if it doesn't fail.

---------

Co-authored-by: Sebastian Thiel <[email protected]>

Author: o2sh

src/info/git/mod.rs

@@ -249,6 +249,7 @@ fn compute_diff_with_parent(
             .into_tree()
             .changes()?
             .track_path()
+            .track_rewrites(None)
             .for_each_to_obtain_tree(&commit.tree()?, |change| {
                 let is_file_change = match change.event {
                     Event::Addition { entry_mode, .. } | Event::Modification { entry_mode, .. } => {

tests/fixtures/make_partial_repo.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+set -eu -o pipefail
+
+mkdir base
+(cd base
+    git init -q
+    git checkout -b main
+    touch code.rs
+    git add code.rs
+    git commit -q -m c1
+    echo hello >> code.rs
+    git add code.rs
+    git commit -q -m c2
+    echo world >> code.rs
+    git add code.rs
+    git commit -q -m c3
+    echo something >> code.rs
+    git add code.rs
+    git commit -q -m c4
+    echo more >> code.rs
+    git mv code.rs renamed.rs
+    echo change >> renamed.rs
+    git commit -q -am c5
+
+    git config uploadpack.allowfilter true
+)
+
+git clone --filter=blob:none file://$PWD/base partial
+(cd partial
+    git config diff.renames true
+)

tests/repo.rs

@@ -4,12 +4,19 @@ use onefetch::cli::{CliOptions, InfoCliOptions, TextForamttingCliOptions};
 use onefetch::info::{build_info, get_work_dir};
 
 fn repo(name: &str) -> Result<Repository> {
-    let name = name.to_string();
     let repo_path = gix_testtools::scripted_fixture_read_only(name).unwrap();
     let safe_repo = ThreadSafeRepository::open_opts(repo_path, open::Options::isolated())?;
     Ok(safe_repo.to_thread_local())
 }
 
+pub fn named_repo(fixture: &str, name: &str) -> Result<Repository> {
+    let repo_path = gix_testtools::scripted_fixture_read_only(fixture)
+        .unwrap()
+        .join(name);
+    let safe_repo = ThreadSafeRepository::open_opts(repo_path, open::Options::isolated())?;
+    Ok(safe_repo.to_thread_local())
+}
+
 #[test]
 fn test_bare_repo() -> Result<()> {
     let repo = repo("bare_repo.sh")?;
@@ -65,3 +72,14 @@ fn test_repo_without_remote() -> Result<()> {
 
     Ok(())
 }
+
+#[test]
+fn test_partial_repo() -> Result<()> {
+    let repo = named_repo("make_partial_repo.sh", "partial")?;
+    let config: CliOptions = CliOptions {
+        input: repo.path().to_path_buf(),
+        ..Default::default()
+    };
+    let _info = build_info(&config).expect("no error");
+    Ok(())
+}