folding: handle view states without provider

src/vs/editor/contrib/folding/folding.ts

@@ -29,9 +29,9 @@ import { LanguageConfigurationRegistry } from 'vs/editor/common/modes/languageCo
 import { IndentRangeProvider } from 'vs/editor/contrib/folding/indentRangeProvider';
 import { IPosition } from 'vs/editor/common/core/position';
 import { FoldingRangeProviderRegistry, FoldingRangeKind } from 'vs/editor/common/modes';
-import { SyntaxRangeProvider } from './syntaxRangeProvider';
+import { SyntaxRangeProvider, ID_SYNTAX_PROVIDER } from './syntaxRangeProvider';
 import { CancellationToken } from 'vs/base/common/cancellation';
-import { InitializingRangeProvider } from 'vs/editor/contrib/folding/intializingRangeProvider';
+import { InitializingRangeProvider, ID_INIT_PROVIDER } from 'vs/editor/contrib/folding/intializingRangeProvider';
 
 export const ID = 'editor.contrib.folding';
 
@@ -155,7 +155,7 @@ export class FoldingController implements IEditorContribution {
 			return;
 		}
 
-		if (state.provider !== 'indent') {
+		if (state.provider === ID_SYNTAX_PROVIDER || state.provider === ID_INIT_PROVIDER) {
 			this.foldingStateMemento = state;
 		}
 

src/vs/editor/contrib/folding/indentRangeProvider.ts

@@ -16,8 +16,10 @@ import { CancellationToken } from 'vs/base/common/cancellation';
 
 const MAX_FOLDING_REGIONS_FOR_INDENT_LIMIT = 5000;
 
+export const ID_INDENT_PROVIDER = 'indent';
+
 export class IndentRangeProvider implements RangeProvider {
-	readonly id = 'indent';
+	readonly id = ID_INDENT_PROVIDER;
 
 	readonly decorations;
 

src/vs/editor/contrib/folding/intializingRangeProvider.ts

@@ -12,8 +12,10 @@ import { TPromise } from 'vs/base/common/winjs.base';
 import { CancellationToken } from 'vs/base/common/cancellation';
 import { IFoldingRangeData, sanitizeRanges } from 'vs/editor/contrib/folding/syntaxRangeProvider';
 
+export const ID_INIT_PROVIDER = 'init';
+
 export class InitializingRangeProvider implements RangeProvider {
-	readonly id = 'init';
+	readonly id = ID_INIT_PROVIDER;
 
 	private decorationIds: string[] | undefined;
 	private timeout: number;

src/vs/editor/contrib/folding/syntaxRangeProvider.ts

@@ -23,9 +23,11 @@ export interface IFoldingRangeData extends FoldingRange {
 const foldingContext: FoldingContext = {
 };
 
+export const ID_SYNTAX_PROVIDER = 'syntax';
+
 export class SyntaxRangeProvider implements RangeProvider {
 
-	readonly id = 'syntax';
+	readonly id = ID_SYNTAX_PROVIDER;
 
 	constructor(private editorModel: ITextModel, private providers: FoldingRangeProvider[], private limit = MAX_FOLDING_REGIONS) {
 	}