From 56cea434dffb3c60ff8748d1ece3a1467ccda4ce Mon Sep 17 00:00:00 2001
From: Sayed Kaif <metsw24@gmail.com>
Date: Mon, 19 Oct 2026 04:41:50 +0530
Subject: [PATCH] normalize rotate and tile angle modulo 360 to avoid 32-bit
 truncation

---
 lib/operation.mjs   |  2 +-
 lib/output.mjs      |  2 +-
 test/unit/rotate.js | 11 +++++++++++
 test/unit/tile.js   | 19 +++++++++++++++++++
 4 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/lib/operation.mjs b/lib/operation.mjs
index d10aa8d00..4dc07fbc8 100644
--- a/lib/operation.mjs
+++ b/lib/operation.mjs
@@ -62,7 +62,7 @@ function rotate (angle, options) {
     this.options.rotationAngle = 0;
   }
   if (is.integer(angle) && !(angle % 90)) {
-    this.options.angle = angle;
+    this.options.angle = angle % 360;
   } else if (is.number(angle)) {
     this.options.rotationAngle = angle;
     if (is.object(options) && options.background) {
diff --git a/lib/output.mjs b/lib/output.mjs
index a5ec90cdb..739a54261 100644
--- a/lib/output.mjs
+++ b/lib/output.mjs
@@ -1518,7 +1518,7 @@ function tile (options) {
     // Angle of rotation,
     if (is.defined(options.angle)) {
       if (is.integer(options.angle) && !(options.angle % 90)) {
-        this.options.tileAngle = options.angle;
+        this.options.tileAngle = options.angle % 360;
       } else {
         throw is.invalidParameterError('angle', 'positive/negative multiple of 90', options.angle);
       }
diff --git a/test/unit/rotate.js b/test/unit/rotate.js
index efb4c2deb..3d18cf83a 100644
--- a/test/unit/rotate.js
+++ b/test/unit/rotate.js
@@ -183,6 +183,17 @@ suite('Rotation', () => {
     });
   });
 
+  // A 90-multiple angle larger than the 32-bit integer range is normalised
+  // modulo 360 rather than silently truncated when read natively
+  [90 * 47721859, 90 * 47721861, -90 * 47721859].forEach((angle) => {
+    test(`Rotate by a 90-multiple angle beyond 32-bit range (${angle}deg)`, async (t) => {
+      t.plan(2);
+      const { info } = await bufferWithInfo(sharp(fixtures.inputJpg320x240).rotate(angle));
+      t.assert.strictEqual(240, info.width);
+      t.assert.strictEqual(320, info.height);
+    });
+  });
+
   [-3750, -510, -150, 30, 390, 3630].forEach((angle) => {
     test(`Rotate by any 30-multiple angle (${angle}deg)`, async (t) => {
       t.plan(2);
diff --git a/test/unit/tile.js b/test/unit/tile.js
index 3e60bfda6..c7b744559 100644
--- a/test/unit/tile.js
+++ b/test/unit/tile.js
@@ -411,6 +411,25 @@ suite('Tile', () => {
       t.assert.strictEqual(true, metadata.height === 170);
     });
 
+    test('Deep Zoom layout with angle beyond 32-bit integer range', async (t) => {
+      const directory = fixtures.path('output.512_largeangle.dzi_files');
+      await fs.rm(directory, { recursive: true, force: true });
+      // 2147483970 is a multiple of 90 equal to 90 modulo 360 but larger than
+      // the signed 32-bit range, so it must rotate as 90 rather than truncate
+      const info = await sharp(fixtures.inputJpg)
+        .tile({
+          size: 512,
+          angle: 2147483970
+        })
+        .toFile(fixtures.path('output.512_largeangle.dzi'));
+      t.plan(3);
+      t.assert.strictEqual('dz', info.format);
+      const tile = path.join(directory, '10', '0_1.jpeg');
+      const metadata = await sharp(tile).metadata();
+      t.assert.strictEqual(true, metadata.width === 512);
+      t.assert.strictEqual(true, metadata.height === 170);
+    });
+
     test('Deep Zoom layout with depth of one', async (t) => {
       const directory = fixtures.path('output.512_depth_one.dzi_files');
       await fs.rm(directory, { recursive: true, force: true });