use debug uri for relative paths; better fix for #61088

src/vs/workbench/parts/debug/browser/debugContentProvider.ts

@@ -56,20 +56,24 @@ export class DebugContentProvider implements IWorkbenchContribution, ITextModelC
 		if (!session) {
 			return Promise.reject(new Error(localize('unable', "Unable to resolve the resource without a debug session")));
 		}
-		const createErrModel = (message: string) => {
+		const createErrModel = (errMsg?: string) => {
 			this.debugService.sourceIsNotAvailable(resource);
 			const modePromise = this.modeService.getOrCreateMode(MIME_TEXT);
+			const message = errMsg
+				? localize('canNotResolveSourceWithError', "Could not load source '{0}': {1}.", resource.path, errMsg)
+				: localize('canNotResolveSource', "Could not load source '{0}'.", resource.path);
 			return this.modelService.createModel(message, modePromise, resource);
 		};
 
 		return session.loadSource(resource).then(response => {
-			if (!response) {
-				return createErrModel(localize('canNotResolveSource', "Could not resolve resource {0}, no response from debug extension.", resource.toString()));
-			}
 
+			if (response && response.body) {
 				const mime = response.body.mimeType || guessMimeTypes(resource.path)[0];
 				const modePromise = this.modeService.getOrCreateMode(mime);
 				return this.modelService.createModel(response.body.content, modePromise, resource);
+			}
+
+			return createErrModel();
 
 		}, (err: DebugProtocol.ErrorResponse) => createErrModel(err.message));
 	}

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

@@ -49,15 +49,16 @@ export class Source {
 		if (this.raw.sourceReference > 0) {
 			this.uri = uri.parse(`${DEBUG_SCHEME}:${encodeURIComponent(path)}?session=${encodeURIComponent(sessionId)}&ref=${this.raw.sourceReference}`);
 		} else {
-			if (isUri(path)) {
+			if (isUri(path)) {	// path looks like a uri
 				this.uri = uri.parse(path);
 			} else {
-				// assume path
+				// assume a filesystem path
 				if (paths.isAbsolute_posix(path) || paths.isAbsolute_win32(path)) {
 					this.uri = uri.file(path);
 				} else {
-					// path is relative: this is not supported but if it happens we create a bogus uri for backward compatibility
-					this.uri = uri.file(path);
+					// path is relative: since VS Code cannot deal with this by itself
+					// create a debug url that will result in a DAP 'source' request when the url is resolved.
+					this.uri = uri.parse(`${DEBUG_SCHEME}:${encodeURIComponent(path)}?session=${encodeURIComponent(sessionId)}`);
 				}
 			}
 		}