Pass flag to PTVSD to ensure file path case sensitivity is preserved (#936)

Fixes #935

Author: DonJayamanne

src/client/debugger/mainV2.ts

@@ -21,6 +21,7 @@ import { DebugProtocol } from 'vscode-debugprotocol';
 import '../../client/common/extensions';
 import { noop, sleep } from '../common/core.utils';
 import { createDeferred, Deferred, isNotInstalledError } from '../common/helpers';
+import { IPlatformService } from '../common/platform/types';
 import { ICurrentProcess } from '../common/types';
 import { IServiceContainer } from '../ioc/types';
 import { AttachRequestArguments, LaunchRequestArguments } from './Common/Contracts';
@@ -333,7 +334,9 @@ class DebugManager implements Disposable {
 
         // Send PTVSD a bogus launch request, and wait for it to respond.
         // This needs to be done, so PTVSD can keep track of how it was launched (whether it as for attach or launch).
-        this.sendMessage(await this.launchRequest, this.ptvsdSocket);
+        const launchRequest = await this.launchRequest;
+        (launchRequest.arguments as any).fixFilePathCase = this.serviceContainer.get<IPlatformService>(IPlatformService).isWindows;
+        this.sendMessage(launchRequest, this.ptvsdSocket);
         await new Promise(resolve => debugSoketProtocolParser.once('response_launch', resolve));
 
         // The PTVSD process has launched, now send the initialize request to it (required by PTVSD).