From b3a4decda677012b8f7cfea39b7741d707c82693 Mon Sep 17 00:00:00 2001
From: Kate Lovett <katelovett@google.com>
Date: Wed, 2 Aug 2023 19:18:13 -0500
Subject: [PATCH] Assert against infinite values of control points in
 CatmullRomSpline (#131820)

When providing infinite values for the control points of CatmullRomSpline, a StackOverflowError occurs. This asserts against that and provides a helpful error message.

Fixes https://github.com/flutter/flutter/issues/131246
---
 .../flutter/lib/src/animation/curves.dart     | 21 ++++++++++
 .../flutter/test/animation/curves_test.dart   | 40 +++++++++++++++++++
 2 files changed, 61 insertions(+)

diff --git a/packages/flutter/lib/src/animation/curves.dart b/packages/flutter/lib/src/animation/curves.dart
index d824c8221ac..0c54a653f03 100644
--- a/packages/flutter/lib/src/animation/curves.dart
+++ b/packages/flutter/lib/src/animation/curves.dart
@@ -705,6 +705,27 @@ class CatmullRomSpline extends Curve2D {
     Offset? startHandle,
     Offset? endHandle,
   }) {
+    assert(
+      startHandle == null || startHandle.isFinite,
+      'The provided startHandle of CatmullRomSpline must be finite. The '
+      'startHandle given was $startHandle.'
+    );
+    assert(
+      endHandle == null || endHandle.isFinite,
+      'The provided endHandle of CatmullRomSpline must be finite. The endHandle '
+      'given was $endHandle.'
+    );
+    assert(() {
+      for (int index = 0; index < controlPoints.length; index++) {
+        if (!controlPoints[index].isFinite) {
+          throw FlutterError(
+            'The provided CatmullRomSpline control point at index $index is not '
+            'finite. The control point given was ${controlPoints[index]}.'
+          );
+        }
+      }
+      return true;
+    }());
     // If not specified, select the first and last control points (which are
     // handles: they are not intersected by the resulting curve) so that they
     // extend the first and last segments, respectively.
diff --git a/packages/flutter/test/animation/curves_test.dart b/packages/flutter/test/animation/curves_test.dart
index 62f426870f5..f7b0757fd5d 100644
--- a/packages/flutter/test/animation/curves_test.dart
+++ b/packages/flutter/test/animation/curves_test.dart
@@ -305,6 +305,28 @@ void main() {
     expect(() {
       CatmullRomSpline(const <Offset>[Offset.zero, Offset.zero, Offset.zero, Offset.zero], tension: 2.0);
     }, throwsAssertionError);
+    expect(() {
+      CatmullRomSpline(
+        const <Offset>[Offset(double.infinity, 0.0), Offset.zero, Offset.zero, Offset.zero],
+      ).generateSamples();
+    }, throwsAssertionError);
+    expect(() {
+      CatmullRomSpline(
+        const <Offset>[Offset(0.0, double.infinity), Offset.zero, Offset.zero, Offset.zero],
+      ).generateSamples();
+    }, throwsAssertionError);
+    expect(() {
+      CatmullRomSpline(
+        startHandle: const Offset(0.0, double.infinity),
+        const <Offset>[Offset.zero, Offset.zero, Offset.zero, Offset.zero],
+      ).generateSamples();
+    }, throwsAssertionError);
+    expect(() {
+      CatmullRomSpline(
+        endHandle: const Offset(0.0, double.infinity),
+        const <Offset>[Offset.zero, Offset.zero, Offset.zero, Offset.zero],
+      ).generateSamples();
+    }, throwsAssertionError);
   });
 
   test('CatmullRomSpline interpolates values properly when precomputed', () {
@@ -353,6 +375,24 @@ void main() {
     expect(() {
       CatmullRomSpline.precompute(const <Offset>[Offset.zero, Offset.zero, Offset.zero, Offset.zero], tension: 2.0);
     }, throwsAssertionError);
+    expect(() {
+      CatmullRomSpline.precompute(const <Offset>[Offset(double.infinity, 0.0), Offset.zero, Offset.zero, Offset.zero]);
+    }, throwsAssertionError);
+    expect(() {
+      CatmullRomSpline.precompute(const <Offset>[Offset(0.0, double.infinity), Offset.zero, Offset.zero, Offset.zero]);
+    }, throwsAssertionError);
+    expect(() {
+      CatmullRomSpline.precompute(
+        startHandle: const Offset(0.0, double.infinity),
+        const <Offset>[Offset.zero, Offset.zero, Offset.zero, Offset.zero],
+      );
+    }, throwsAssertionError);
+    expect(() {
+      CatmullRomSpline.precompute(
+        endHandle: const Offset(0.0, double.infinity),
+        const <Offset>[Offset.zero, Offset.zero, Offset.zero, Offset.zero],
+      );
+    }, throwsAssertionError);
   });
 
   test('CatmullRomCurve interpolates given points correctly', () {