From dab73aa26355d8897968bffe3fc3366c2ca80a28 Mon Sep 17 00:00:00 2001
From: Puneethnaik <puneethn250@gmail.com>
Date: Wed, 28 Jul 2021 15:56:26 +0000
Subject: [PATCH 1/2] update the viewportElement style width upon refreshing of
 the viewport to accomodate changes in scrollBarWidth

---
 demo/client.ts          |  3 +++
 src/browser/Viewport.ts | 10 +++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/demo/client.ts b/demo/client.ts
index 0bb124cd..7b675520 100644
--- a/demo/client.ts
+++ b/demo/client.ts
@@ -348,6 +348,9 @@ function initOptions(term: TerminalType): void {
       } else if (o === 'lineHeight' || o === 'scrollSensitivity') {
         term.setOption(o, parseFloat(input.value));
         updateTerminalSize();
+      } else if(o === 'scrollback') {
+        term.setOption(o, parseInt(input.value));
+        setTimeout(() => updateTerminalSize(), 5);
       } else {
         term.setOption(o, parseInt(input.value));
       }
diff --git a/src/browser/Viewport.ts b/src/browser/Viewport.ts
index 162ed174..77325ef9 100644
--- a/src/browser/Viewport.ts
+++ b/src/browser/Viewport.ts
@@ -93,7 +93,12 @@ export class Viewport extends Disposable implements IViewport {
       this._ignoreNextScrollEvent = true;
       this._viewportElement.scrollTop = scrollTop;
     }
-
+    if (this._optionsService.getOption('scrollback') === 0) {
+      this.scrollBarWidth = 0;
+    } else {
+      this.scrollBarWidth = (this._viewportElement.offsetWidth - this._scrollArea.offsetWidth) || FALLBACK_SCROLL_BAR_WIDTH;
+    }
+    this._viewportElement.style.width = (this._renderService.dimensions.actualCellWidth * (this._bufferService.cols) + this.scrollBarWidth).toString() + 'px';
     this._refreshAnimationFrame = null;
   }
   /**
@@ -131,6 +136,9 @@ export class Viewport extends Disposable implements IViewport {
       this._refresh(immediate);
       return;
     }
+    // This is for refreshing the viewport if scrollBarWidth has to be updated
+    this._refresh(immediate);
+    return;
   }
 
   /**

From 640ea60945794aaadc17acc14bcc8f5673989b5d Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Mon, 30 Aug 2021 10:48:12 -0700
Subject: [PATCH 2/2] Action feedback

---
 src/browser/Viewport.ts | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/browser/Viewport.ts b/src/browser/Viewport.ts
index 77325ef9..9ce14daf 100644
--- a/src/browser/Viewport.ts
+++ b/src/browser/Viewport.ts
@@ -23,6 +23,7 @@ export class Viewport extends Disposable implements IViewport {
   private _lastRecordedBufferHeight: number = 0;
   private _lastTouchY: number = 0;
   private _lastScrollTop: number = 0;
+  private _lastHadScrollBar: boolean = false;
 
   // Stores a partial line amount when scrolling, this is used to keep track of how much of a line
   // is scrolled so we can "scroll" over partial lines and feel natural on touchpads. This is a
@@ -47,6 +48,7 @@ export class Viewport extends Disposable implements IViewport {
     // Unfortunately the overlay scrollbar would be hidden underneath the screen element in that case,
     // therefore we account for a standard amount to make it visible
     this.scrollBarWidth = (this._viewportElement.offsetWidth - this._scrollArea.offsetWidth) || FALLBACK_SCROLL_BAR_WIDTH;
+    this._lastHadScrollBar = true;
     this.register(addDisposableDomListener(this._viewportElement, 'scroll', this._onScroll.bind(this)));
 
     // Perform this async to ensure the ICharSizeService is ready.
@@ -93,14 +95,19 @@ export class Viewport extends Disposable implements IViewport {
       this._ignoreNextScrollEvent = true;
       this._viewportElement.scrollTop = scrollTop;
     }
-    if (this._optionsService.getOption('scrollback') === 0) {
+
+    // Update scroll bar width
+    if (this._optionsService.options.scrollback === 0) {
       this.scrollBarWidth = 0;
     } else {
       this.scrollBarWidth = (this._viewportElement.offsetWidth - this._scrollArea.offsetWidth) || FALLBACK_SCROLL_BAR_WIDTH;
     }
+    this._lastHadScrollBar = this.scrollBarWidth > 0;
+
     this._viewportElement.style.width = (this._renderService.dimensions.actualCellWidth * (this._bufferService.cols) + this.scrollBarWidth).toString() + 'px';
     this._refreshAnimationFrame = null;
   }
+
   /**
    * Updates dimensions and synchronizes the scroll area if necessary.
    */
@@ -136,9 +143,11 @@ export class Viewport extends Disposable implements IViewport {
       this._refresh(immediate);
       return;
     }
-    // This is for refreshing the viewport if scrollBarWidth has to be updated
-    this._refresh(immediate);
-    return;
+
+    // If the scroll bar visibility changed
+    if (this._lastHadScrollBar !== (this._optionsService.options.scrollback > 0)) {
+      this._refresh(immediate);
+    }
   }
 
   /**