From 9513c231c970c33f17b79f8b30a890e1687b19ad Mon Sep 17 00:00:00 2001
From: Tony Brix <tony@brix.ninja>
Date: Fri, 11 Sep 2020 00:42:18 -0500
Subject: [PATCH] fix: rerender hidden terminal when visible

---
 src/browser/services/RenderService.ts | 10 +++++++++-
 test/api/Terminal.api.ts              |  8 ++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/browser/services/RenderService.ts b/src/browser/services/RenderService.ts
index 5c91ebaf..6cd18738 100644
--- a/src/browser/services/RenderService.ts
+++ b/src/browser/services/RenderService.ts
@@ -24,6 +24,7 @@ export class RenderService extends Disposable implements IRenderService {
 
   private _renderDebouncer: RenderDebouncer;
   private _screenDprMonitor: ScreenDprMonitor;
+  private _charSizeService: ICharSizeService;
 
   private _isPaused: boolean = false;
   private _needsFullRefresh: boolean = false;
@@ -67,7 +68,9 @@ export class RenderService extends Disposable implements IRenderService {
 
     this.register(bufferService.onResize(e => this._fullRefresh()));
     this.register(optionsService.onOptionChange(() => this._renderer.onOptionsChanged()));
-    this.register(charSizeService.onCharSizeChange(() => this.onCharSizeChanged()));
+
+    this._charSizeService = charSizeService;
+    this.register(this._charSizeService.onCharSizeChange(() => this.onCharSizeChanged()));
 
     // No need to register this as renderer is explicitly disposed in RenderService.dispose
     this._renderer.onRequestRedraw(e => this.refreshRows(e.start, e.end, true));
@@ -91,6 +94,11 @@ export class RenderService extends Disposable implements IRenderService {
       this.refreshRows(0, this._rowCount - 1);
       this._needsFullRefresh = false;
     }
+
+    // Terminal was hidden on open
+    if (!this._isPaused && !this._charSizeService.hasValidSize) {
+      this._charSizeService.measure();
+    }
   }
 
   public refreshRows(start: number, end: number, isRedrawOnly: boolean = false): void {
diff --git a/test/api/Terminal.api.ts b/test/api/Terminal.api.ts
index 99cb9b2a..c5ce8f92 100644
--- a/test/api/Terminal.api.ts
+++ b/test/api/Terminal.api.ts
@@ -572,6 +572,14 @@ describe('API Integration Tests', function(): void {
     assert.equal(await page.evaluate(`window.term._core._isDisposed`), true);
   });
 
+  it('render when visible after hidden', async () => {
+    await page.evaluate(`document.querySelector('#terminal-container').style.display='none'`);
+    await page.evaluate(`window.term = new Terminal()`);
+    await page.evaluate(`window.term.open(document.querySelector('#terminal-container'))`);
+    await page.evaluate(`document.querySelector('#terminal-container').style.display=''`);
+    await pollFor(page, `window.term._core._renderService.dimensions.actualCellWidth > 0`, true);
+  });
+
   describe('registerLinkProvider', () => {
     it('should fire provideLinks when hovering cells', async () => {
       await openTerminal(page, { rendererType: 'dom' });