From d0ef1c1f867a6f9a6ecabec2a3f4df4b44bd9365 Mon Sep 17 00:00:00 2001
From: Bruno Leroux <bruno.leroux@gmail.com>
Date: Tue, 18 Mar 2025 07:48:21 +0100
Subject: [PATCH] [Android] Fix crash on some key repeat events (#165307)

## Description

This PR fixes a crash on Android related to specific keyboard events.
It is very similar to http://github.com/flutter/engine/issues/35924
which was related to down events. This PR fixes the similar logic
related to repeat events.

## Related Issue

Fixes [Flutter 3.29 Fatal crash with
java.lang.AssertionError](https://github.com/flutter/flutter/issues/164626)

## Tests

Adds 1 test.
---
 .../android/KeyEmbedderResponder.java         |  2 +-
 .../android/KeyboardManagerTest.java          | 62 +++++++++++++++++++
 2 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/engine/src/flutter/shell/platform/android/io/flutter/embedding/android/KeyEmbedderResponder.java b/engine/src/flutter/shell/platform/android/io/flutter/embedding/android/KeyEmbedderResponder.java
index de5af6b0ff..520f55ab6c 100644
--- a/engine/src/flutter/shell/platform/android/io/flutter/embedding/android/KeyEmbedderResponder.java
+++ b/engine/src/flutter/shell/platform/android/io/flutter/embedding/android/KeyEmbedderResponder.java
@@ -183,7 +183,7 @@ public class KeyEmbedderResponder implements KeyboardManager.Responder {
               postSynchronize.add(
                   () ->
                       synthesizeEvent(
-                          false, key.logicalKey, key.physicalKey, event.getEventTime()));
+                          false, key.logicalKey, eventPhysicalKey, event.getEventTime()));
             }
             preEventStates[keyIdx] = nowStates[keyIdx];
             postEventAnyPressed = true;
diff --git a/engine/src/flutter/shell/platform/android/test/io/flutter/embedding/android/KeyboardManagerTest.java b/engine/src/flutter/shell/platform/android/test/io/flutter/embedding/android/KeyboardManagerTest.java
index 4c7b3ee3dc..2dfa602c3e 100644
--- a/engine/src/flutter/shell/platform/android/test/io/flutter/embedding/android/KeyboardManagerTest.java
+++ b/engine/src/flutter/shell/platform/android/test/io/flutter/embedding/android/KeyboardManagerTest.java
@@ -1669,6 +1669,68 @@ public class KeyboardManagerTest {
     calls.clear();
   }
 
+  // Regression test for https://github.com/flutter/flutter/issues/164626.
+  @Test
+  public void synchronizeModifiersForZeroedScanCodeOnRepeatEvent() {
+    // Test if ShiftLeft can be correctly synchronized during down events of
+    // ShiftLeft that have 0 for their metaState and 0 for their scanCode.
+    final KeyboardTester tester = new KeyboardTester();
+    final ArrayList<CallRecord> calls = new ArrayList<>();
+
+    tester.recordEmbedderCallsTo(calls);
+    tester.respondToTextInputWith(true); // Suppress redispatching
+
+    // Test: repeat event when the meta state is 0 and scanCode is 0.
+    final KeyEvent shiftLeftKeyEvent =
+        new FakeKeyEvent(ACTION_DOWN, 0, KEYCODE_SHIFT_LEFT, 1, '\0', 0);
+    // Compute physicalKey in the same way as KeyboardManager.getPhysicalKey.
+    final Long shiftLeftPhysicalKey = KEYCODE_SHIFT_LEFT | KeyboardMap.kAndroidPlane;
+
+    assertEquals(tester.keyboardManager.handleEvent(shiftLeftKeyEvent), true);
+    assertEquals(calls.size(), 2);
+    assertEmbedderEventEquals(
+        calls.get(0).keyData,
+        Type.kDown,
+        shiftLeftPhysicalKey,
+        LOGICAL_SHIFT_LEFT,
+        null,
+        false,
+        DeviceType.kKeyboard);
+    assertEmbedderEventEquals(
+        calls.get(1).keyData,
+        Type.kUp,
+        shiftLeftPhysicalKey,
+        LOGICAL_SHIFT_LEFT,
+        null,
+        true,
+        DeviceType.kKeyboard);
+    calls.clear();
+
+    // Similar check for AltLeft.
+    final KeyEvent altLeftKeyEvent = new FakeKeyEvent(ACTION_DOWN, 0, KEYCODE_ALT_LEFT, 1, '\0', 0);
+    final Long altLeftPhysicalKey = KEYCODE_ALT_LEFT | KeyboardMap.kAndroidPlane;
+
+    assertEquals(tester.keyboardManager.handleEvent(altLeftKeyEvent), true);
+    assertEquals(calls.size(), 2);
+    assertEmbedderEventEquals(
+        calls.get(0).keyData,
+        Type.kDown,
+        altLeftPhysicalKey,
+        LOGICAL_ALT_LEFT,
+        null,
+        false,
+        DeviceType.kKeyboard);
+    assertEmbedderEventEquals(
+        calls.get(1).keyData,
+        Type.kUp,
+        altLeftPhysicalKey,
+        LOGICAL_ALT_LEFT,
+        null,
+        true,
+        DeviceType.kKeyboard);
+    calls.clear();
+  }
+
   @Test
   public void normalCapsLockEvents() {
     final KeyboardTester tester = new KeyboardTester();