Ensure flip and flop operations work with auto-rotate #837

docs/changelog.md

@@ -10,6 +10,10 @@ Requires libvips v8.5.5.
   [#828](https://github.com/lovell/sharp/pull/828)
   [@YvesBos](https://github.com/YvesBos)
 
+* Ensure flip and flop operations work with auto-rotate.
+  [#837](https://github.com/lovell/sharp/issues/837)
+  [@rexxars](https://github.com/rexxars)
+
 #### v0.18.1 - 30<sup>th</sup> May 2017
 
 * Remove regression from #781 that could cause incorrect shrink calculation.

src/pipeline.cc

@@ -83,8 +83,11 @@ class PipelineWorker : public Nan::AsyncWorker {
       VipsAngle rotation;
       if (baton->useExifOrientation) {
         // Rotate and flip image according to Exif orientation
-        // (ignore the requested rotation and flip)
+        bool flip;
-        std::tie(rotation, baton->flip, baton->flop) = CalculateExifRotationAndFlip(sharp::ExifOrientation(image));
+        bool flop;
+        std::tie(rotation, flip, flop) = CalculateExifRotationAndFlip(sharp::ExifOrientation(image));
+        baton->flip = baton->flip || flip;
+        baton->flop = baton->flop || flop;
       } else {
         rotation = CalculateAngleRotation(baton->angle);
       }

test/unit/rotate.js

@@ -253,4 +253,32 @@ describe('Rotation', function () {
         fixtures.assertSimilar(fixtures.inputJpg, data, done);
       });
   });
+
+  it('Auto-rotate and flip', function (done) {
+    sharp(fixtures.inputJpgWithExif)
+      .rotate()
+      .flip()
+      .resize(320)
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual('jpeg', info.format);
+        assert.strictEqual(320, info.width);
+        assert.strictEqual(240, info.height);
+        fixtures.assertSimilar(fixtures.expected('rotate-and-flip.jpg'), data, done);
+      });
+  });
+
+  it('Auto-rotate and flop', function (done) {
+    sharp(fixtures.inputJpgWithExif)
+      .rotate()
+      .flop()
+      .resize(320)
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual('jpeg', info.format);
+        assert.strictEqual(320, info.width);
+        assert.strictEqual(240, info.height);
+        fixtures.assertSimilar(fixtures.expected('rotate-and-flop.jpg'), data, done);
+      });
+  });
 });