fix(mr): bound conflict paths with exact-sized copies

commit: f09b4fb25aba68e46dc33cc6637af6750f1c0946
author: brice · 2d ago · 2026-10-19 14:52 UTC
committer: brice · 2d ago · 2026-10-19 18:30 UTC
parent: f8b1d20
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

2 files · +30 -2

M internal/domain/mergerequest.go +12 -2


@@ -540,10 +540,20 @@ type MergeTreeResult struct {
540	540		// set when some were dropped. Adapters return the raw result; the bound is
541	541		// the domain's.
542	542		func (r MergeTreeResult) Bounded() MergeTreeResult {
543		-	if len(r.ConflictPaths) > MaxConflictPaths {
544		-	r.ConflictPaths = r.ConflictPaths[:MaxConflictPaths:MaxConflictPaths]
	543	+	kept := r.ConflictPaths
	544	+	if len(kept) > MaxConflictPaths {
	545	+	kept = kept[:MaxConflictPaths]
545	546		r.Truncated = true
546	547		}
	548	+	if kept != nil {
	549	+	// Exact-sized copies: neither the backing array nor the git output the
	550	+	// paths were cut from stays referenced.
	551	+	out := make([]string, len(kept))
	552	+	for i, p := range kept {
	553	+	out[i] = strings.Clone(p)
	554	+	}
	555	+	r.ConflictPaths = out
	556	+	}
547	557		return r
548	558		}
549	559

 // set when some were dropped. Adapters return the raw result; the bound is
 // the domain's.
 func (r MergeTreeResult) Bounded() MergeTreeResult {
-	if len(r.ConflictPaths) > MaxConflictPaths {
+	kept := r.ConflictPaths
-		r.ConflictPaths = r.ConflictPaths[:MaxConflictPaths:MaxConflictPaths]
+	if len(kept) > MaxConflictPaths {
+		kept = kept[:MaxConflictPaths]
 		r.Truncated = true
 	}
+	if kept != nil {
+		// Exact-sized copies: neither the backing array nor the git output the
+		// paths were cut from stays referenced.
+		out := make([]string, len(kept))
+		for i, p := range kept {
+			out[i] = strings.Clone(p)
+		}
+		r.ConflictPaths = out
+	}
 	return r
 }

M internal/domain/mergetree_bound_test.go +18 -0


@@ -7,6 +7,7 @@ import (
7	7		"testing"
8	8
9	9		"github.com/stretchr/testify/assert"
	10	+	"github.com/stretchr/testify/require"
10	11
11	12		"bnema.dev/ermite/internal/domain"
12	13		)

@@ -33,3 +34,20 @@ func TestBoundBehind(t *testing.T) {
33	34		assert.Equal(t, domain.MaxBehindCount, n)
34	35		assert.True(t, capped)
35	36		}
	37	+
	38	+	func TestMergeTreeResultBoundedCopiesThePaths(t *testing.T) {
	39	+	var paths []string
	40	+	for i := 0; i < domain.MaxConflictPaths+2; i++ {
	41	+	paths = append(paths, strconv.Itoa(i))
	42	+	}
	43	+	got := domain.MergeTreeResult{ConflictPaths: paths}.Bounded()
	44	+	require.Len(t, got.ConflictPaths, domain.MaxConflictPaths)
	45	+	assert.Equal(t, len(got.ConflictPaths), cap(got.ConflictPaths))
	46	+	assert.NotSame(t, &paths[0], &got.ConflictPaths[0], "a new array, not the git output's")
	47	+	assert.Equal(t, paths[:domain.MaxConflictPaths], got.ConflictPaths)
	48	+
	49	+	got = domain.MergeTreeResult{ConflictPaths: paths[:3:10]}.Bounded()
	50	+	assert.Equal(t, 3, cap(got.ConflictPaths))
	51	+	assert.False(t, got.Truncated)
	52	+	assert.Nil(t, domain.MergeTreeResult{}.Bounded().ConflictPaths)
	53	+	}


@@ -7,6 +7,7 @@ import (
7	"testing"	7		"testing"
8		8
9	"github.com/stretchr/testify/assert"	9		"github.com/stretchr/testify/assert"
		10	+	"github.com/stretchr/testify/require"
10		11
11	"bnema.dev/ermite/internal/domain"	12		"bnema.dev/ermite/internal/domain"
12	)	13		)

@@ -33,3 +34,20 @@ func TestBoundBehind(t *testing.T) {
33	assert.Equal(t, domain.MaxBehindCount, n)	34		assert.Equal(t, domain.MaxBehindCount, n)
34	assert.True(t, capped)	35		assert.True(t, capped)
35	}	36		}
		37	+
		38	+	func TestMergeTreeResultBoundedCopiesThePaths(t *testing.T) {
		39	+	var paths []string
		40	+	for i := 0; i < domain.MaxConflictPaths+2; i++ {
		41	+	paths = append(paths, strconv.Itoa(i))
		42	+	}
		43	+	got := domain.MergeTreeResult{ConflictPaths: paths}.Bounded()
		44	+	require.Len(t, got.ConflictPaths, domain.MaxConflictPaths)
		45	+	assert.Equal(t, len(got.ConflictPaths), cap(got.ConflictPaths))
		46	+	assert.NotSame(t, &paths[0], &got.ConflictPaths[0], "a new array, not the git output's")
		47	+	assert.Equal(t, paths[:domain.MaxConflictPaths], got.ConflictPaths)
		48	+
		49	+	got = domain.MergeTreeResult{ConflictPaths: paths[:3:10]}.Bounded()
		50	+	assert.Equal(t, 3, cap(got.ConflictPaths))
		51	+	assert.False(t, got.Truncated)
		52	+	assert.Nil(t, domain.MergeTreeResult{}.Bounded().ConflictPaths)
		53	+	}