From 03e607a6e7748611438001b5a4b46ba64a1f1c52 Mon Sep 17 00:00:00 2001
From: qinghuan <qinghuan@pinduoduo.com>
Date: Mon, 15 Apr 2024 22:02:32 +0800
Subject: [PATCH] fix: bug in SetPages

---
 vips/image.go      |  2 +-
 vips/image_test.go | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/vips/image.go b/vips/image.go
index 20afe99e..01aba400 100644
--- a/vips/image.go
+++ b/vips/image.go
@@ -766,7 +766,7 @@ func (r *ImageRef) SetPages(pages int) error {
 		return err
 	}
 
-	vipsSetImageNPages(r.image, pages)
+	vipsSetImageNPages(out, pages)
 
 	r.setImage(out)
 	return nil
diff --git a/vips/image_test.go b/vips/image_test.go
index 4783a2f4..987942cc 100644
--- a/vips/image_test.go
+++ b/vips/image_test.go
@@ -1169,6 +1169,18 @@ func TestImageRef_HistogramEntropy(t *testing.T) {
 	require.True(t, e > 0)
 }
 
+func TestImageRef_SetPages(t *testing.T) {
+	Startup(nil)
+
+	image, err := NewImageFromFile(resources + "gif-animated.gif")
+	require.NoError(t, err)
+	require.Equal(t, 8, image.Pages())
+
+	err = image.SetPages(3)
+	require.NoError(t, err)
+	require.Equal(t, 3, image.Pages())
+}
+
 // TODO unit tests to cover:
 // NewImageFromReader failing test
 // NewImageFromFile failing test