Fix multiple linter support (#2571) (#3702)

Author: nullie

news/2 Fixes/2571.md

@@ -0,0 +1,2 @@
+Fix bug affecting multiple linters used in a workspace.
+(thanks [Ilia Novoselov](https://github.com/nullie))

src/client/common/process/proc.ts

@@ -168,17 +168,20 @@ export class ProcessService implements IProcessService {
     }
 
     private getDefaultOptions<T extends (ShellOptions | SpawnOptions)>(options: T) : T {
-        const execOptions = options as SpawnOptions;
-        const defaultOptions = JSON.parse(JSON.stringify(options));
+        const defaultOptions = { ...options };
+        const execOptions = defaultOptions as SpawnOptions;
         if (execOptions)
         {
             const encoding = execOptions.encoding = typeof execOptions.encoding === 'string' && execOptions.encoding.length > 0 ? execOptions.encoding : DEFAULT_ENCODING;
             delete execOptions.encoding;
-            defaultOptions.encoding = encoding;
+            execOptions.encoding = encoding;
+            execOptions.token = execOptions.token;
         }
-        if (!defaultOptions.env || Object.keys(defaultOptions).length === 0) {
+        if (!defaultOptions.env || Object.keys(defaultOptions.env).length === 0) {
             const env = this.env ? this.env : process.env;
             defaultOptions.env = { ...env };
+        } else {
+            defaultOptions.env = { ...defaultOptions.env };
         }
 
         // Always ensure we have unbuffered output.

src/test/linters/lint.test.ts

@@ -271,17 +271,6 @@ suite('Linting - General Tests', () => {
     });
     // tslint:disable-next-line:no-function-expression
     test('Multiple linters', async function () {
-        //      Unreliable test being skipped until we can sort it out.  See gh-2609.
-        //          - Fails about 1/3 of runs on Windows
-        //          - Symptom: lintingEngine::lintOpenPythonFiles returns values *after* command await resolves in lint.tests
-        //          - lintOpenPythonFiles returns 3 sets of values, not what I expect (1).
-        //          - Haven't yet found a way to await on this properly.
-        const skipped = true;
-        if (skipped) {
-            // tslint:disable-next-line:no-invalid-this
-            return this.skip();
-        }
-
         await closeActiveWindows();
         const document = await workspace.openTextDocument(path.join(pythoFilesPath, 'print.py'));
         await window.showTextDocument(document);