Urgh I made some wrong amends and I'm too tired to separate the commits out this time

ancestor: Split out of reachability
mergebase: Add merge base routines
internal/commitquery: Add commit query context engine thingy
internal/peel: Shared tag peeling
errors: Shared object query errors
internal/testgit: Add rooted repo helpers; remove raw path access
objectstore/memory: Add in-memory object store
objectid: Add Compare helper

1 files changed, 27 insertions, 0 deletions

diff --git a/internal/commitquery/parent.go b/internal/commitquery/parent.go
new file mode 100644
index 00000000..17695e09
--- /dev/null
+++ b/internal/commitquery/parent.go
@@ -0,0 +1,27 @@
+package commitquery
+
+import (
+	commitgraphread "codeberg.org/lindenii/furgit/format/commitgraph/read"
+	"codeberg.org/lindenii/furgit/objectid"
+)
+
+// Parent references one commit parent.
+type Parent struct {
+	ID          objectid.ObjectID
+	GraphPos    commitgraphread.Position
+	HasGraphPos bool
+}
+
+// Parents returns resolved parent node indices for one internal node.
+func (ctx *Context) Parents(idx NodeIndex) []NodeIndex {
+	return ctx.nodes[idx].parents
+}
+
+// resolveParent resolves one parent descriptor to one internal node.
+func (ctx *Context) resolveParent(parent Parent) (NodeIndex, error) {
+	if parent.HasGraphPos {
+		return ctx.ResolveGraphPos(parent.GraphPos)
+	}
+
+	return ctx.ResolveOID(parent.ID)
+}