Merge from vscode 52dcb723a39ae75bee1bd56b3312d7fcdc87aeed (#6719)

src/vs/editor/common/viewModel/characterHardWrappingLineMapper.ts

@@ -136,6 +136,13 @@ export class CharacterHardWrappingLineMapperFactory implements ILineMapperFactor
 			let charCodeIsTab = (charCode === CharCode.Tab);
 			let charCodeClass = classifier.get(charCode);
 
+			if (strings.isLowSurrogate(charCode)/*  && i + 1 < len */) {
+				// A surrogate pair must always be considered as a single unit, so it is never to be broken
+				// => advance visibleColumn by 1 and advance to next char code...
+				visibleColumn = visibleColumn + 1;
+				continue;
+			}
+
 			if (charCodeClass === CharacterClass.BREAK_BEFORE) {
 				// This is a character that indicates that a break should happen before it
 				// Since we are certain the character before `i` fits, there's no extra checking needed,

src/vs/editor/common/viewModel/splitLinesCollection.ts

@@ -155,13 +155,13 @@ export class SplitLinesCollection implements IViewModelLinesCollection {
 	private columnsForFullWidthChar: number;
 	private wrappingIndent: WrappingIndent;
 	private tabSize: number;
-	private lines: ISplitLine[];
+	private lines!: ISplitLine[];
 
-	private prefixSumComputer: PrefixSumComputerWithCache;
+	private prefixSumComputer!: PrefixSumComputerWithCache;
 
 	private readonly linePositionMapperFactory: ILineMapperFactory;
 
-	private hiddenAreasIds: string[];
+	private hiddenAreasIds!: string[];
 
 	constructor(model: ITextModel, linePositionMapperFactory: ILineMapperFactory, tabSize: number, wrappingColumn: number, columnsForFullWidthChar: number, wrappingIndent: WrappingIndent) {
 		this.model = model;

src/vs/editor/common/viewModel/viewModelDecorations.ts

@@ -42,7 +42,8 @@ export class ViewModelDecorations implements IDisposable {
 		this._linesCollection = linesCollection;
 		this._coordinatesConverter = coordinatesConverter;
 		this._decorationsCache = Object.create(null);
-		this._clearCachedModelDecorationsResolver();
+		this._cachedModelDecorationsResolver = null;
+		this._cachedModelDecorationsResolverViewRange = null;
 	}
 
 	private _clearCachedModelDecorationsResolver(): void {