From f8eaab4fdc70a01e42ea232fc83702cb7b43eb58 Mon Sep 17 00:00:00 2001
From: Joshua Gross <joshuagross@fb.com>
Date: Thu, 22 Oct 2020 13:50:46 -0700
Subject: [PATCH] Workaround for T76236115 and swallow crash while using
 TextEdit

Summary:
There's a crash for a small number of users that looks like it is happening when cutting the text via a context menu, or deleting content near the end.

This is only happening because we cache the Spannable and it detects changes due to the cache mechanism itself. I'm making a minor change that will hopefully result
in Spannables being copied instead of the same Spannable instances being used for display on the View and measurement; and also swallowing this error, since it should
not be considered as a fatal, unrecoverable error for now. Hopefully we can delete entirely in the future.

Changelog: [Internal]

Reviewed By: shergin

Differential Revision: D24430622

fbshipit-source-id: 495458b3d85733e46a7e62b5c954b7cb6b00470b
---
 .../react/views/textinput/ReactEditText.java  | 37 ++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactEditText.java b/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactEditText.java
index 4d4147215d8..db843323724 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactEditText.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactEditText.java
@@ -41,6 +41,7 @@ import androidx.core.view.ViewCompat;
 import com.facebook.common.logging.FLog;
 import com.facebook.infer.annotation.Assertions;
 import com.facebook.react.bridge.ReactContext;
+import com.facebook.react.bridge.ReactSoftException;
 import com.facebook.react.common.build.ReactBuildConfig;
 import com.facebook.react.uimanager.FabricViewStateManager;
 import com.facebook.react.uimanager.UIManagerModule;
@@ -992,7 +993,41 @@ public class ReactEditText extends AppCompatEditText
     // can modify the spans of sb/currentText, impact the text or spans visible on screen, and
     // also call the TextChangeWatcher methods.
     if (haveText) {
-      sb.append(currentText);
+      // This is here as a workaround for T76236115, which looks like this:
+      // Hopefully we can delete all this stuff if we can get rid of the soft errors.
+      // - android.text.SpannableStringBuilder.charAt (SpannableStringBuilder.java:123)
+      // - android.text.CharSequenceCharacterIterator.current
+      // (CharSequenceCharacterIterator.java:58)
+      // - android.text.CharSequenceCharacterIterator.setIndex
+      // (CharSequenceCharacterIterator.java:83)
+      // - android.icu.text.RuleBasedBreakIterator.CISetIndex32 (RuleBasedBreakIterator.java:1126)
+      // - android.icu.text.RuleBasedBreakIterator.isBoundary (RuleBasedBreakIterator.java:503)
+      // - android.text.method.WordIterator.isBoundary (WordIterator.java:95)
+      // - android.widget.Editor$SelectionHandleView.positionAtCursorOffset (Editor.java:6666)
+      // - android.widget.Editor$HandleView.invalidate (Editor.java:5241)
+      // - android.widget.Editor$SelectionModifierCursorController.invalidateHandles
+      // (Editor.java:7442)
+      // - android.widget.Editor.invalidateHandlesAndActionMode (Editor.java:2112)
+      // - android.widget.TextView.spanChange (TextView.java:11189)
+      // - android.widget.TextView$ChangeWatcher.onSpanAdded (TextView.java:14189)
+      // - android.text.SpannableStringBuilder.sendSpanAdded (SpannableStringBuilder.java:1283)
+      // - android.text.SpannableStringBuilder.sendToSpanWatchers (SpannableStringBuilder.java:663)
+      // - android.text.SpannableStringBuilder.replace (SpannableStringBuilder.java:579)
+      // - android.text.SpannableStringBuilder.append (SpannableStringBuilder.java:269)
+      // - ReactEditText.updateCachedSpannable (ReactEditText.java:995)
+      // - ReactEditText$TextWatcherDelegator.onTextChanged (ReactEditText.java:1044)
+      // - android.widget.TextView.sendOnTextChanged (TextView.java:10972)
+      // ...
+      // - android.text.method.BaseKeyListener.onKeyDown (BaseKeyListener.java:479)
+      // - android.text.method.QwertyKeyListener.onKeyDown (QwertyKeyListener.java:362)
+      // - ReactEditText$InternalKeyListener.onKeyDown (ReactEditText.java:1094)
+      // ...
+      // - android.app.Activity.dispatchKeyEvent (Activity.java:3447)
+      try {
+        sb.append(currentText.subSequence(0, currentText.length()));
+      } catch (IndexOutOfBoundsException e) {
+        ReactSoftException.logSoftException(TAG, e);
+      }
     }
 
     // If we don't have text, make sure we have *something* to measure.