Deleting character causes documentSymbol to fail with BadLocationException

[fbricon]

Always reproducible on vscode.
given:

public class Foo {
	public static void main(String[] args) {
		"foooooooo".substring(1);
	}
}

Every time you remove delete a character (also happens, less frequently on other actions, like completion), outline fails to be computed, log spits:

Params: {
    "type": 1,
    "message": "17-Sep-2018 4:28:27 PM 
null
org.eclipse.jface.text.BadLocationException
org.eclipse.jface.text.TreeLineTracker.fail(TreeLineTracker.java:1054)
org.eclipse.jface.text.TreeLineTracker.lineByOffset(TreeLineTracker.java:268)
org.eclipse.jface.text.TreeLineTracker.getLineNumberOfOffset(TreeLineTracker.java:1122)
org.eclipse.jface.text.AbstractLineTracker.getLineNumberOfOffset(AbstractLineTracker.java:154)
org.eclipse.jface.text.AbstractDocument.getLineOfOffset(AbstractDocument.java:871)
org.eclipse.core.internal.filebuffers.SynchronizableDocument.getLineOfOffset(SynchronizableDocument.java:334)
org.eclipse.jdt.ls.core.internal.handlers.JsonRpcHelpers.toLine(JsonRpcHelpers.java:60)
org.eclipse.jdt.ls.core.internal.JDTUtils.toRange(JDTUtils.java:533)
org.eclipse.jdt.ls.core.internal.JDTUtils.toLocation(JDTUtils.java:447)
org.eclipse.jdt.ls.core.internal.JDTUtils.toLocation(JDTUtils.java:393)
org.eclipse.jdt.ls.core.internal.handlers.DocumentSymbolHandler.getRange(DocumentSymbolHandler.java:174)
org.eclipse.jdt.ls.core.internal.handlers.DocumentSymbolHandler.toDocumentSymbol(DocumentSymbolHandler.java:148)
org.eclipse.jdt.ls.core.internal.handlers.DocumentSymbolHandler.lambda$2(DocumentSymbolHandler.java:127)
java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193) java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948) java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481) java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708) java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
org.eclipse.jdt.ls.core.internal.handlers.DocumentSymbolHandler.getHierarchicalOutline(DocumentSymbolHandler.java:127) org.eclipse.jdt.ls.core.internal.handlers.DocumentSymbolHandler.documentSymbol(DocumentSymbolHandler.java:72)
org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$13(JDTLanguageServer.java:556)
org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$26(JDTLanguageServer.java:762)...
}