From e6e03a226f8574a9b2743cac1d757360be7eb1b4 Mon Sep 17 00:00:00 2001
From: Samuel Mannehed <samuel@cendio.se>
Date: Fri, 27 Dec 2024 12:47:38 +0100
Subject: [PATCH] Fix resizes back to initial remote session size

Since the expected client size wasn't updated when the browser window
resized, noVNC didn't resize the canvas properly when going back to
the exact same dimensions.

Fixes issue #1903
---
 core/rfb.js       |  1 +
 tests/test.rfb.js | 65 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/core/rfb.js b/core/rfb.js
index 9559e487..e1482c3f 100644
--- a/core/rfb.js
+++ b/core/rfb.js
@@ -730,6 +730,7 @@ export default class RFB extends EventTargetMixin {
         window.requestAnimationFrame(() => {
             this._updateClip();
             this._updateScale();
+            this._saveExpectedClientSize();
         });
 
         if (this._resizeSession) {
diff --git a/tests/test.rfb.js b/tests/test.rfb.js
index 19894ba1..7e406321 100644
--- a/tests/test.rfb.js
+++ b/tests/test.rfb.js
@@ -730,6 +730,28 @@ describe('Remote Frame Buffer protocol client', function () {
             container.style.width = '70px';
             container.style.height = '80px';
             client.scaleViewport = true;
+
+            const incoming = [ 0x00,        // msg-type=FBU
+                               0x00,        // padding
+                               0x00, 0x01,  // number of rects = 1
+                               0x00, 0x00,  // reason = server initialized
+                               0x00, 0x00,  // status = no error
+                               0x00, 0x04,  // new width = 4
+                               0x00, 0x04,  // new height = 4
+                               0xff, 0xff,
+                               0xfe, 0xcc,  // enc = (-308) ExtendedDesktopSize
+                               0x01,        // number of screens = 1
+                               0x00, 0x00,
+                               0x00,        // padding
+                               0x78, 0x90,
+                               0xab, 0xcd,  // screen id = 0
+                               0x00, 0x00,  // screen x = 0
+                               0x00, 0x00,  // screen y = 0
+                               0x00, 0x04,  // screen width = 4
+                               0x00, 0x04,  // screen height = 4
+                               0x12, 0x34,
+                               0x56, 0x78]; // screen flags
+            client._sock._websocket._receiveData(new Uint8Array(incoming));
         });
 
         it('should update display scale factor when changing the property', function () {
@@ -774,6 +796,28 @@ describe('Remote Frame Buffer protocol client', function () {
             expect(client._display.autoscale).to.have.been.calledWith(40, 50);
         });
 
+        it('should update the scaling resized back to initial size', function () {
+            sinon.spy(client._display, "autoscale");
+
+            container.style.width = '40px';
+            container.style.height = '50px';
+            fakeResizeObserver.fire();
+            clock.tick(1000);
+
+            expect(client._display.autoscale).to.have.been.calledOnce;
+            expect(client._display.autoscale).to.have.been.calledWith(40, 50);
+            client._display.autoscale.resetHistory();
+
+            container.style.width = '70px';
+            container.style.height = '80px';
+            fakeResizeObserver.fire();
+            clock.tick(1000);
+
+            expect(client._display.autoscale).to.have.been.calledOnce;
+            expect(client._display.autoscale).to.have.been.calledWith(70, 80);
+            client._display.autoscale.resetHistory();
+        });
+
         it('should update the scaling when the remote session resizes', function () {
             // Simple ExtendedDesktopSize FBU message
             const incoming = [ 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
@@ -941,6 +985,27 @@ describe('Remote Frame Buffer protocol client', function () {
             expect(RFB.messages.setDesktopSize).to.not.have.been.called;
         });
 
+        it('should request a resize when resized back to initial size', function () {
+            container.style.width = '40px';
+            container.style.height = '50px';
+            fakeResizeObserver.fire();
+            clock.tick(1000);
+
+            expect(RFB.messages.setDesktopSize).to.have.been.calledOnce;
+            expect(RFB.messages.setDesktopSize).to.have.been.calledWith(
+                sinon.match.object, 40, 50, 0x7890abcd, 0x12345678);
+            RFB.messages.setDesktopSize.resetHistory();
+
+            container.style.width = '70px';
+            container.style.height = '80px';
+            fakeResizeObserver.fire();
+            clock.tick(1000);
+
+            expect(RFB.messages.setDesktopSize).to.have.been.calledOnce;
+            expect(RFB.messages.setDesktopSize).to.have.been.calledWith(
+                sinon.match.object, 70, 80, 0x7890abcd, 0x12345678);
+        });
+
         it('should not resize until the container size is stable', function () {
             container.style.width = '20px';
             container.style.height = '30px';