From 4cb4af22f52675b82a0c5d513e8f1227b5f7946a Mon Sep 17 00:00:00 2001
From: oppiliappan <me@oppi.li>
Date: Sun, 8 Jun 2025 11:42:50 +0100
Subject: [PATCH] knotserver: git: remove MergeBase calculation
Change-Id: mwvlmmytozoplsuukxzoypvpunptrrpk

the rev-list approach to building format-patch internally performs
merge-base calculations.

Signed-off-by: oppiliappan <me@oppi.li>
---
 knotserver/git/diff.go | 25 +------------------------
 knotserver/routes.go   | 10 +---------
 types/repo.go          |  2 +-
 3 files changed, 3 insertions(+), 34 deletions(-)

diff --git a/knotserver/git/diff.go b/knotserver/git/diff.go
index 5c1f402..fa2c2b0 100644
--- a/knotserver/git/diff.go
+++ b/knotserver/git/diff.go
@@ -166,28 +166,6 @@ func (g *GitRepo) formatSinglePatch(base, commit2 plumbing.Hash, extraArgs ...st
 	return stdout.String(), &formatPatch[0], nil
 }
 
-func (g *GitRepo) MergeBase(commit1, commit2 *object.Commit) (*object.Commit, error) {
-	isAncestor, err := commit1.IsAncestor(commit2)
-	if err != nil {
-		return nil, err
-	}
-
-	if isAncestor {
-		return commit1, nil
-	}
-
-	mergeBase, err := commit1.MergeBase(commit2)
-	if err != nil {
-		return nil, err
-	}
-
-	if len(mergeBase) == 0 {
-		return nil, fmt.Errorf("failed to find a merge-base")
-	}
-
-	return mergeBase[0], nil
-}
-
 func (g *GitRepo) ResolveRevision(revStr string) (*object.Commit, error) {
 	rev, err := g.r.ResolveRevision(plumbing.Revision(revStr))
 	if err != nil {
@@ -224,7 +202,6 @@ func (g *GitRepo) commitsBetween(newCommit, oldCommit *object.Commit) ([]*object
 		if err != nil {
 			continue
 		}
-
 		commits = append(commits, obj)
 	}
 
@@ -232,7 +209,7 @@ func (g *GitRepo) commitsBetween(newCommit, oldCommit *object.Commit) ([]*object
 }
 
 func (g *GitRepo) FormatPatch(base, commit2 *object.Commit) (string, []types.FormatPatch, error) {
-	// get list of commits between commir2 and base
+	// get list of commits between commit2 and base
 	commits, err := g.commitsBetween(commit2, base)
 	if err != nil {
 		return "", nil, fmt.Errorf("failed to get commits: %w", err)
diff --git a/knotserver/routes.go b/knotserver/routes.go
index 7424c99..89b5fb0 100644
--- a/knotserver/routes.go
+++ b/knotserver/routes.go
@@ -1096,14 +1096,7 @@ func (h *Handle) Compare(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	mergeBase, err := gr.MergeBase(commit1, commit2)
-	if err != nil {
-		l.Error("failed to find merge-base", "msg", err.Error())
-		writeError(w, "failed to calculate diff", http.StatusBadRequest)
-		return
-	}
-
-	rawPatch, formatPatch, err := gr.FormatPatch(mergeBase, commit2)
+	rawPatch, formatPatch, err := gr.FormatPatch(commit1, commit2)
 	if err != nil {
 		l.Error("error comparing revisions", "msg", err.Error())
 		writeError(w, "error comparing revisions", http.StatusBadRequest)
@@ -1114,7 +1107,6 @@ func (h *Handle) Compare(w http.ResponseWriter, r *http.Request) {
 		Rev1:        commit1.Hash.String(),
 		Rev2:        commit2.Hash.String(),
 		FormatPatch: formatPatch,
-		MergeBase:   mergeBase.Hash.String(),
 		Patch:       rawPatch,
 	})
 	return
diff --git a/types/repo.go b/types/repo.go
index 985da9e..04d7cad 100644
--- a/types/repo.go
+++ b/types/repo.go
@@ -36,7 +36,7 @@ type RepoFormatPatchResponse struct {
 	Rev1        string        `json:"rev1,omitempty"`
 	Rev2        string        `json:"rev2,omitempty"`
 	FormatPatch []FormatPatch `json:"format_patch,omitempty"`
-	MergeBase   string        `json:"merge_base,omitempty"`
+	MergeBase   string        `json:"merge_base,omitempty"` // deprecated
 	Patch       string        `json:"patch,omitempty"`
 }
 
-- 
2.43.0