From 873750609f4c81f14bfe061e0e211ea85daa7eb5 Mon Sep 17 00:00:00 2001
From: Marc Laval <mlaval@amadeus.com>
Date: Fri, 18 Jan 2019 14:16:41 +0100
Subject: [PATCH] fix(ivy): calling ChangeDetectorRef.detectChanges() from
 onChanges should not go infinite loop (#28239)

PR Close #28239
---
 packages/core/src/render3/instructions.ts     |  3 +
 .../test/render3/change_detection_spec.ts     | 60 ++++++++++++++++++-
 2 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/packages/core/src/render3/instructions.ts b/packages/core/src/render3/instructions.ts
index f7bdef173c..2caf10d34f 100644
--- a/packages/core/src/render3/instructions.ts
+++ b/packages/core/src/render3/instructions.ts
@@ -68,6 +68,9 @@ export function refreshDescendantViews(lView: LView) {
   tView.firstTemplatePass = false;
   setFirstTemplatePass(false);
 
+  // Resetting the bindingIndex of the current LView as the next steps may trigger change detection.
+  lView[BINDING_INDEX] = tView.bindingStartIndex;
+
   // If this is a creation pass, we should not call lifecycle hooks or evaluate bindings.
   // This will be done in the update pass.
   if (!isCreationMode(lView)) {
diff --git a/packages/core/test/render3/change_detection_spec.ts b/packages/core/test/render3/change_detection_spec.ts
index 3f65e9fc25..1a7909caf7 100644
--- a/packages/core/test/render3/change_detection_spec.ts
+++ b/packages/core/test/render3/change_detection_spec.ts
@@ -11,7 +11,7 @@ import {withBody} from '@angular/private/testing';
 
 import {ChangeDetectionStrategy, ChangeDetectorRef, DoCheck, RendererType2} from '../../src/core';
 import {whenRendered} from '../../src/render3/component';
-import {LifecycleHooksFeature, defineComponent, defineDirective, getRenderedText, templateRefExtractor} from '../../src/render3/index';
+import {LifecycleHooksFeature, NgOnChangesFeature, defineComponent, defineDirective, getRenderedText, templateRefExtractor} from '../../src/render3/index';
 
 import {bind, container, containerRefreshEnd, containerRefreshStart, detectChanges, directiveInject, element, elementEnd, elementProperty, elementStart, embeddedViewEnd, embeddedViewStart, interpolation1, interpolation2, listener, markDirty, reference, text, template, textBinding, tick} from '../../src/render3/instructions';
 import {RenderFlags} from '../../src/render3/interfaces/definition';
@@ -562,6 +562,64 @@ describe('change detection', () => {
         expect(getRenderedText(comp)).toEqual('1');
       });
 
+
+      it('should not go infinite loop when recursively called from children\'s ngOnChanges', () => {
+        class ChildComp {
+          // @Input
+          inp = '';
+
+          count = 0;
+          constructor(public parentComp: ParentComp) {}
+
+          ngOnChanges() {
+            this.count++;
+            if (this.count > 1) throw new Error(`ngOnChanges should be called only once!`);
+            this.parentComp.triggerChangeDetection();
+          }
+
+          static ngComponentDef = defineComponent({
+            type: ChildComp,
+            selectors: [['child-comp']],
+            factory: () => new ChildComp(directiveInject(ParentComp as any)),
+            consts: 1,
+            vars: 0,
+            template: (rf: RenderFlags, ctx: ChildComp) => {
+              if (rf & RenderFlags.Create) {
+                text(0, 'foo');
+              }
+            },
+            inputs: {inp: 'inp'},
+            features: [NgOnChangesFeature]
+          });
+        }
+
+        class ParentComp {
+          constructor(public cdr: ChangeDetectorRef) {}
+
+          triggerChangeDetection() { this.cdr.detectChanges(); }
+
+          static ngComponentDef = defineComponent({
+            type: ParentComp,
+            selectors: [['parent-comp']],
+            factory: () => new ParentComp(directiveInject(ChangeDetectorRef as any)),
+            consts: 1,
+            vars: 1,
+            /** {{ value }} */
+            template: (rf: RenderFlags, ctx: ParentComp) => {
+              if (rf & RenderFlags.Create) {
+                element(0, 'child-comp');
+              }
+              if (rf & RenderFlags.Update) {
+                elementProperty(0, 'inp', bind(true));
+              }
+            },
+            directives: [ChildComp]
+          });
+        }
+
+        expect(() => renderComponent(ParentComp)).not.toThrow();
+      });
+
       it('should support call in ngDoCheck', () => {
         class DetectChangesComp {
           doCheckCount = 0;