debug: do not handle cancled errors as success cases

fixes #18772

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

@@ -687,10 +687,6 @@ export class DebugService implements debug.IDebugService {
 				supportsVariablePaging: true, // #9537
 				supportsRunInTerminalRequest: true // #10574
 			}).then((result: DebugProtocol.InitializeResponse) => {
-				if (session.disconnected) {
-					return TPromise.wrapError(new Error(nls.localize('debugAdapterCrash', "Debug adapter process has terminated unexpectedly")));
-				}
-
 				this.model.setExceptionBreakpoints(session.configuration.capabilities.exceptionBreakpointFilters);
 				return configuration.request === 'attach' ? session.attach(configuration) : session.launch(configuration);
 			}).then((result: DebugProtocol.Response) => {

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

@@ -140,8 +140,7 @@ export class RawDebugSession extends v8.V8Protocol implements debug.ISession {
 		}, err => {
 			this.cachedInitServer = null;
 			return TPromise.wrapError(err);
-		}
-		);
+		});
 
 		return this.cachedInitServer;
 	}
@@ -162,10 +161,6 @@ export class RawDebugSession extends v8.V8Protocol implements debug.ISession {
 						this.customTelemetryService.publicLog('debugProtocolErrorResponse', { error: telemetryMessage });
 					}
 				}
-				if (errors.isPromiseCanceledError(errorResponse) || (error && error.showUser === false)) {
-					// Do not show error message to user if showUser === false or 'canceled' error message #7906
-					return TPromise.as(null);
-				}
 
 				const userMessage = error ? debug.formatPII(error.format, false, error.variables) : errorMessage;
 				if (error && error.url) {