[VS4Mac][Editor] Break editor after paste large text.

[wcoder]

Steps:

1. Write:

   var str = "";
   Byte[] bytes = Convert.FromBase64String(str);

2. Paste large text to str (length: 2214888);
3. Editor be broken (look at images below).

Actual:

After selection:

Expected:

Screen from SublimeText:

System info:

=== Visual Studio Community 2019 for Mac ===

Version 8.5.1 (build 42)
Installation UUID: 718c9426-9b34-4dad-a550-66605f1e5527
    GTK+ 2.24.23 (Raleigh theme)
    Xamarin.Mac 6.14.1.39 (d16-5 / 30e8706b4)

    Package version: 608000123

=== Mono Framework MDK ===

Runtime:
    Mono 6.8.0.123 (2019-10/1d0d939dc30) (64-bit)
    Package version: 608000123

=== Roslyn (Language Service) ===

3.5.0-beta4-20125-04+1baa0b3063238ed752ad1f0368b1df6b6901373e

=== NuGet ===

Version: 5.4.0.6315

=== .NET Core SDK ===

SDK: /usr/local/share/dotnet/sdk/3.1.200/Sdks
SDK Versions:
    3.1.200
    3.1.102
MSBuild SDKs: /Library/Frameworks/Mono.framework/Versions/6.8.0/lib/mono/msbuild/Current/bin/Sdks

=== .NET Core Runtime ===

Runtime: /usr/local/share/dotnet/dotnet
Runtime Versions:
    3.1.2
    2.1.16

=== Xamarin.Profiler ===

Version: 1.6.13.11
Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler

=== Updater ===

Version: 11

=== Apple Developer Tools ===

Xcode 11.4 (16134)
Build 11E146

=== Xamarin.Mac ===

Version: 6.16.0.11 (Visual Studio Community)
Hash: aa73e4125
Branch: d16-5-xcode11.4
Build date: 2020-03-25 11:04:02-0400

=== Xamarin.iOS ===

Version: 13.16.0.11 (Visual Studio Community)
Hash: aa73e4125
Branch: d16-5-xcode11.4
Build date: 2020-03-25 11:04:03-0400

=== Xamarin.Android ===

Version: 10.2.0.100 (Visual Studio Community)
Commit: xamarin-android/d16-5/988c811
Android SDK: /Users/yauhenipakala/Library/Developer/Xamarin/android-sdk-macosx
    Supported Android versions:
        7.0 (API level 24)
        8.0 (API level 26)
        8.1 (API level 27)

SDK Tools Version: 26.1.1
SDK Platform Tools Version: 29.0.6
SDK Build Tools Version: 29.0.3

Build Information: 
Mono: c0c5c78
Java.Interop: xamarin/java.interop/d16-5@fc18c54
ProGuard: xamarin/proguard/master@905836d
SQLite: xamarin/sqlite/3.28.0@46204c4
Xamarin.Android Tools: xamarin/xamarin-android-tools/d16-5@9f4ed4b

=== Microsoft Mobile OpenJDK ===

Java SDK: /Users/yauhenipakala/Library/Developer/Xamarin/jdk/microsoft_dist_openjdk_1.8.0.25
1.8.0-25
Android Designer EPL code available here:
https://github.com/xamarin/AndroidDesigner.EPL

=== Android SDK Manager ===

Version: 16.5.0.39
Hash: 6fb4c79
Branch: remotes/origin/d16-5
Build date: 2020-03-28 00:48:52 UTC

=== Android Device Manager ===

Version: 16.5.0.71
Hash: 49194e8
Branch: remotes/origin/d16-5~1
Build date: 2020-03-28 00:49:12 UTC

=== Xamarin Inspector ===

Version: 1.4.3
Hash: db27525
Branch: 1.4-release
Build date: Mon, 09 Jul 2018 21:20:18 GMT
Client compatibility: 1

=== Xamarin Designer ===

Version: 16.5.0.471
Hash: 35aa4889d
Branch: remotes/origin/d16-5
Build date: 2020-02-25 00:52:08 UTC

=== Build Information ===

Release ID: 805010042
Git revision: 926c6e86370a6d68fc930f0600932e0a9192e3da
Build date: 2020-03-30 17:14:37-04
Build branch: release-8.5
Xamarin extensions: 926c6e86370a6d68fc930f0600932e0a9192e3da

=== Operating System ===

Mac OS X 10.15.4
Darwin 19.4.0 Darwin Kernel Version 19.4.0
    Wed Mar  4 22:28:40 PST 2020
    root:xnu-6153.101.6~15/RELEASE_X86_64 x86_64

=== Enabled user installed extensions ===

BinObjCleaner 1.5
MonoDevelop.TouchBar 1.0.3
DT.VS4Mac.SolutionName 1.2
Code Coverage 2.0.1-alpha

[sandyarmstrong]

@wcoder would you mind filing this bug at https://developercommunity.visualstudio.com/content/problem/post.html?space=41 ?

[wcoder]

Sure, linked: https://developercommunity.visualstudio.com/content/problem/981023/vs4maceditor-break-editor-after-paste-large-text.html