From 973eb7b350315f4cd004644b496305a685986711 Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Tue, 11 May 2021 05:10:04 -0700
Subject: [PATCH 1/3] Make sure all rows are refreshed on input

Fixes #3323
---
 src/browser/Viewport.ts | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/src/browser/Viewport.ts b/src/browser/Viewport.ts
index 02f74ce8..7b377a47 100644
--- a/src/browser/Viewport.ts
+++ b/src/browser/Viewport.ts
@@ -30,7 +30,6 @@ export class Viewport extends Disposable implements IViewport {
   private _wheelPartialScroll: number = 0;
 
   private _refreshAnimationFrame: number | null = null;
-  private _ignoreNextScrollEvent: boolean = false;
 
   constructor(
     private readonly _scrollLines: (amount: number) => void,
@@ -88,14 +87,12 @@ export class Viewport extends Disposable implements IViewport {
     // Sync scrollTop
     const scrollTop = this._bufferService.buffer.ydisp * this._currentRowHeight;
     if (this._viewportElement.scrollTop !== scrollTop) {
-      // Ignore the next scroll event which will be triggered by setting the scrollTop as we do not
-      // want this event to scroll the terminal
-      this._ignoreNextScrollEvent = true;
       this._viewportElement.scrollTop = scrollTop;
     }
 
     this._refreshAnimationFrame = null;
   }
+
   /**
    * Updates dimensions and synchronizes the scroll area if necessary.
    */
@@ -148,12 +145,6 @@ export class Viewport extends Disposable implements IViewport {
       return;
     }
 
-    // Ignore the event if it was flagged to ignore (when the source of the event is from Viewport)
-    if (this._ignoreNextScrollEvent) {
-      this._ignoreNextScrollEvent = false;
-      return;
-    }
-
     const newRow = Math.round(this._lastScrollTop / this._currentRowHeight);
     const diff = newRow - this._bufferService.buffer.ydisp;
     this._scrollLines(diff);

From da39129bd2cba926e7c7ef4d20d6154c685b6889 Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Tue, 11 May 2021 05:10:04 -0700
Subject: [PATCH 2/3] Revert "Make sure all rows are refreshed on input"

This reverts commit 973eb7b350315f4cd004644b496305a685986711.
---
 src/browser/Viewport.ts | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/browser/Viewport.ts b/src/browser/Viewport.ts
index 7b377a47..02f74ce8 100644
--- a/src/browser/Viewport.ts
+++ b/src/browser/Viewport.ts
@@ -30,6 +30,7 @@ export class Viewport extends Disposable implements IViewport {
   private _wheelPartialScroll: number = 0;
 
   private _refreshAnimationFrame: number | null = null;
+  private _ignoreNextScrollEvent: boolean = false;
 
   constructor(
     private readonly _scrollLines: (amount: number) => void,
@@ -87,12 +88,14 @@ export class Viewport extends Disposable implements IViewport {
     // Sync scrollTop
     const scrollTop = this._bufferService.buffer.ydisp * this._currentRowHeight;
     if (this._viewportElement.scrollTop !== scrollTop) {
+      // Ignore the next scroll event which will be triggered by setting the scrollTop as we do not
+      // want this event to scroll the terminal
+      this._ignoreNextScrollEvent = true;
       this._viewportElement.scrollTop = scrollTop;
     }
 
     this._refreshAnimationFrame = null;
   }
-
   /**
    * Updates dimensions and synchronizes the scroll area if necessary.
    */
@@ -145,6 +148,12 @@ export class Viewport extends Disposable implements IViewport {
       return;
     }
 
+    // Ignore the event if it was flagged to ignore (when the source of the event is from Viewport)
+    if (this._ignoreNextScrollEvent) {
+      this._ignoreNextScrollEvent = false;
+      return;
+    }
+
     const newRow = Math.round(this._lastScrollTop / this._currentRowHeight);
     const diff = newRow - this._bufferService.buffer.ydisp;
     this._scrollLines(diff);

From bcbcc71bfc4e275d77703d724eb85a6152636acd Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Tue, 11 May 2021 06:52:04 -0700
Subject: [PATCH 3/3] Trigger scroll when ignoring event

This is a less aggressive fix that doesn't regress tests
---
 src/browser/Viewport.ts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/browser/Viewport.ts b/src/browser/Viewport.ts
index 02f74ce8..162ed174 100644
--- a/src/browser/Viewport.ts
+++ b/src/browser/Viewport.ts
@@ -151,6 +151,8 @@ export class Viewport extends Disposable implements IViewport {
     // Ignore the event if it was flagged to ignore (when the source of the event is from Viewport)
     if (this._ignoreNextScrollEvent) {
       this._ignoreNextScrollEvent = false;
+      // Still trigger the scroll so lines get refreshed
+      this._scrollLines(0);
       return;
     }