debug: make sure to send a breakpoints request when all bps have been removed

fixes #1985

src/vs/workbench/parts/debug/common/debugSource.ts

@@ -36,13 +36,15 @@ export class Source {
 	}
 
 	public static toRawSource(uri: uri, model: IModel): DebugProtocol.Source {
-		// first try to find the raw source amongst the stack frames - since that represenation has more data (source reference),
-		const threads = model.getThreads();
-		for (let threadId in threads) {
-			if (threads.hasOwnProperty(threadId) && threads[threadId].callStack) {
-				const found = threads[threadId].callStack.filter(sf => sf.source.uri.toString() === uri.toString()).pop();
-				if (found) {
-					return found.source.raw;
+		if (model) {
+			// first try to find the raw source amongst the stack frames - since that represenation has more data (source reference),
+			const threads = model.getThreads();
+			for (let threadId in threads) {
+				if (threads.hasOwnProperty(threadId) && threads[threadId].callStack) {
+					const found = threads[threadId].callStack.filter(sf => sf.source.uri.toString() === uri.toString()).pop();
+					if (found) {
+						return found.source.raw;
+					}
 				}
 			}
 		}

src/vs/workbench/parts/debug/electron-browser/debugService.ts

@@ -782,15 +782,17 @@ export class DebugService extends ee.EventEmitter implements debug.IDebugService
 	}
 
 	private sendBreakpoints(modelUri: uri): Promise {
+		if (!this.session || !this.session.readyForBreakpoints) {
+			return Promise.as(null);
+		}
+
 		const breakpointsToSend = arrays.distinct(
 			this.model.getBreakpoints().filter(bp => this.model.areBreakpointsActivated() && bp.enabled && bp.source.uri.toString() === modelUri.toString()),
 			bp => `${ bp.desiredLineNumber }`
 		);
-		if (!this.session || !this.session.readyForBreakpoints || breakpointsToSend.length === 0) {
-			return Promise.as(null);
-		}
+		const rawSource = breakpointsToSend.length > 0 ? breakpointsToSend[0].source.raw : Source.toRawSource(modelUri, null);
 
-		return this.session.setBreakpoints({ source: breakpointsToSend[0].source.raw, lines: breakpointsToSend.map(bp => bp.desiredLineNumber),
+		return this.session.setBreakpoints({ source: rawSource, lines: breakpointsToSend.map(bp => bp.desiredLineNumber),
 			breakpoints: breakpointsToSend.map(bp => ({ line: bp.desiredLineNumber, condition: bp.condition })) }).then(response => {
 
 			const data: {[id: string]: { line: number, verified: boolean } } = { };