Rainbow Braces: Possible crash with References window

[tomasr]

Possible repro:

• Ensure Reference Window is closed (not just hidden) when VS is started
• Open CS project
• Right click a function in a code file and select Find all References command

Aparent exception:

    <record>920</record>
    <time>2018/05/28 22:19:07.187</time>
    <type>Error</type>
    <source>Editor or Editor Extension</source>
    <description>System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.&#x000D;&#x000A;Parameter name: position&#x000D;&#x000A;   at Microsoft.VisualStudio.Text.SnapshotPoint..ctor(ITextSnapshot snapshot, Int32 position)&#x000D;&#x000A;   at Winterdom.Viasfora.Rainbow.RainbowProvider.UpdateBraceList(SnapshotPoint startPoint, Boolean notifyUpdate)&#x000D;&#x000A;   at Winterdom.Viasfora.Rainbow.RainbowProvider.UpdateBraceList(ITextSnapshot snapshot, INormalizedTextChangeCollection changes)&#x000D;&#x000A;   at Winterdom.Viasfora.Rainbow.RainbowProvider.BufferChanged(Object sender, TextContentChangedEventArgs e)&#x000D;&#x000A;   at Microsoft.VisualStudio.Text.Utilities.GuardedOperations.RaiseEvent[TArgs](Object sender, EventHandler`1 eventHandlers, TArgs args)&#x000D;&#x000A;--- End of stack trace from previous location where exception was thrown ---&#x000D;&#x000A;   at Microsoft.VisualStudio.Telemetry.WindowsErrorReporting.WatsonReport.GetClrWatsonExceptionInfo(Exception exceptionObject)</description>
  </entry>

[tomasr]

This was caused by the tooltips in the Reference Windows. When you moved from one line to the other, the TextView and TextBuffer gets reused, but the buffer first is reduced to an empty buffer.