[odb #190] Read all eligble packed refs, no "pack-" prefix needed

This allows to read packs which are differently named which is what
git and libgit2 do, too.

Author: Byron

git-odb/src/store/compound/init.rs

@@ -34,10 +34,7 @@ impl compound::Store {
                     .filter_map(Result::ok)
                     .filter_map(|e| e.metadata().map(|md| (e.path(), md)).ok())
                     .filter(|(_, md)| md.file_type().is_file())
-                    .filter(|(p, _)| {
-                        p.extension().unwrap_or_default() == "idx"
-                            && p.file_name().unwrap_or_default().to_string_lossy().starts_with("pack-")
-                    })
+                    .filter(|(p, _)| p.extension().unwrap_or_default() == "idx")
                     // TODO: make this configurable, git for instance sorts by modification date
                     //       https://github.com/libgit2/libgit2/blob/main/src/odb_pack.c#L41-L158
                     .map(|(p, md)| pack::Bundle::at(p).map(|b| (b, md.len())))

git-odb/tests/fixtures/repos/small-packs.git/HEAD

@@ -0,0 +1 @@
+ref: refs/heads/main

git-odb/tests/fixtures/repos/small-packs.git/config

@@ -0,0 +1,7 @@
+[core]
+	bare = true
+	repositoryformatversion = 0
+	filemode = true
+	ignorecase = true
+	precomposeunicode = true
+	logallrefupdates = true

git-odb/tests/fixtures/repos/small-packs.git/description

@@ -0,0 +1 @@
+Unnamed repository; edit this file 'description' to name the repository.

git-odb/tests/fixtures/repos/small-packs.git/info/exclude

@@ -0,0 +1,2 @@
+# File patterns to ignore; see `git help ignore` for more information.
+# Lines that start with '#' are comments.

git-odb/tests/fixtures/repos/small-packs.git/objects/pack/09a90be3fe6db2b49e35858c529e4b9c687b9a08.idx

@@ -0,0 +1 @@
+ecc68100297fff843a7eef8df0d0fb80c1c8bac5

git-odb/tests/fixtures/repos/small-packs.git/objects/pack/09a90be3fe6db2b49e35858c529e4b9c687b9a08.pack

@@ -3,4 +3,5 @@ pub use git_testtools::{fixture_path, hex_to_id, scripted_fixture_repo_read_only
 pub type Result<T = ()> = std::result::Result<T, Box<dyn std::error::Error>>;
 
 pub mod alternate;
+pub mod regression;
 pub mod store;

git-odb/tests/fixtures/repos/small-packs.git/objects/pack/216edf2f7a671742705e6ca8a639daacfcf91217.idx

@@ -0,0 +1,23 @@
+mod repo_with_small_packs {
+    use crate::odb::{fixture_path, hex_to_id};
+    use git_odb::pack;
+
+    #[test]
+    fn all_packed_objects_can_be_found() {
+        let store = git_odb::linked::Store::at(fixture_path("repos/small-packs.git/objects")).unwrap();
+        assert_eq!(store.dbs.len(), 1, "a simple repo");
+        let db = &store.dbs[0];
+        assert_eq!(db.bundles.len(), 2, "small packs");
+        let mut buf = Vec::new();
+        assert!(
+            db.try_find(
+                hex_to_id("ecc68100297fff843a7eef8df0d0fb80c1c8bac5"),
+                &mut buf,
+                &mut pack::cache::Never
+            )
+            .unwrap()
+            .is_some(),
+            "object is present and available"
+        );
+    }
+}