From 71f1daab6eb916b025ac2ea6361fc82564ba28ac Mon Sep 17 00:00:00 2001
From: Nikolaj Vorobiev <nikolaj.vorobiev@golang.cz>
Date: Wed, 15 Apr 2026 14:31:50 +0200
Subject: [PATCH] fix(table): keep external pointer aliases valid after saveAll
 inserts

---
 table.go            | 10 ++++++++--
 tests/table_test.go | 30 ++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/table.go b/table.go
index 3e96fd5..b185f46 100644
--- a/table.go
+++ b/table.go
@@ -321,6 +321,10 @@ func (t *Table[T, P, I]) saveAll(ctx context.Context, records []P) error {
 	for start := 0; start < len(insertRecords); start += chunkSize {
 		end := min(start+chunkSize, len(insertRecords))
 
+		// Preserve original pointers before GetAll replaces them with newly allocated structs.
+		originals := make([]P, end-start)
+		copy(originals, insertRecords[start:end])
+
 		chunk := insertRecords[start:end]
 		q := t.SQL.
 			InsertRecords(chunk).
@@ -331,9 +335,11 @@ func (t *Table[T, P, I]) saveAll(ctx context.Context, records []P) error {
 			return fmt.Errorf("insert records: %w", err)
 		}
 
-		// update original slice
+		// Copy DB-returned values into the original structs so external pointer
+		// aliases taken before Save remain valid (same behaviour as saveOne/GetOne).
 		for i, rr := range chunk {
-			records[insertIndices[start+i]] = rr
+			*originals[i] = *rr
+			records[insertIndices[start+i]] = originals[i]
 		}
 	}
 
diff --git a/tests/table_test.go b/tests/table_test.go
index b3356a6..c1b0d02 100644
--- a/tests/table_test.go
+++ b/tests/table_test.go
@@ -68,6 +68,36 @@ func TestTable(t *testing.T) {
 		}
 	})
 
+	t.Run("Save external alias updated", func(t *testing.T) {
+		t.Parallel()
+		account := &Account{Name: "Alias Account"}
+		err := db.Accounts.Save(ctx, account)
+		require.NoError(t, err)
+
+		// Take aliases BEFORE Save — simulates real-world usage where callers
+		// keep a reference to the original pointer expecting it to be mutated.
+		slice := []*Article{
+			{Author: "AliasFirst", AccountID: account.ID},
+			{Author: "AliasSecond", AccountID: account.ID},
+		}
+		alias0 := slice[0]
+		alias1 := slice[1]
+
+		err = db.Articles.Save(ctx, slice...)
+		require.NoError(t, err)
+
+		require.NotZero(t, slice[0].ID)
+		require.NotZero(t, slice[1].ID)
+
+		// The alias pointer must be the same object as the slice element.
+		require.Same(t, slice[0], alias0, "alias0 should still point to the same struct as slice[0]")
+		require.Same(t, slice[1], alias1, "alias1 should still point to the same struct as slice[1]")
+
+		// And it must carry the DB-assigned ID.
+		require.Equal(t, slice[0].ID, alias0.ID, "alias0.ID should reflect the DB-assigned value")
+		require.Equal(t, slice[1].ID, alias1.ID, "alias1.ID should reflect the DB-assigned value")
+	})
+
 	t.Run("Save multiple", func(t *testing.T) {
 		t.Parallel()
 		// Create account.