fix(@angular/cli): allow build output in outDir outside of project

Author: hansl

packages/@angular/cli/models/webpack-configs/common.ts

@@ -99,11 +99,12 @@ export function getCommonConfig(wco: WebpackConfigOptions) {
       // specify a configuration flag.
       // Also prevent writing outside the project path. That is not overridable.
       const fullOutputPath = path.resolve(buildOptions.outputPath, asset.output);
-      if (!fullOutputPath.startsWith(projectRoot)) {
-        const message = 'An asset cannot be written to a location outside the project.';
-        throw new SilentError(message);
-      }
       if (!fullOutputPath.startsWith(path.resolve(buildOptions.outputPath))) {
+        if (!fullOutputPath.startsWith(projectRoot)) {
+          const message = 'An asset cannot be written to a location outside the project.';
+          throw new SilentError(message);
+        }
+
         if (!asset.allowOutsideOutDir) {
           const message = 'An asset cannot be written to a location outside of the output path. '
                         + 'You can override this message by setting the `allowOutsideOutDir` '

tests/e2e/tests/build/assets.ts

@@ -55,6 +55,21 @@ export default function () {
     }))
     .then(() => expectToFail(() => ng('build')))
 
+    // This asset will not fail with the exception above.
+    .then(() => updateJsonFile('.angular-cli.json', configJson => {
+      const app = configJson['apps'][0];
+      app['outDir'] = '../../temp';
+      app['assets'] = [
+        { 'glob': '**/*', 'input': '../node_modules/some-package/', 'output': '../../temp',
+          'allowOutsideOutDir': true }
+      ];
+    }))
+    .then(() => ng('build'))
+    .then(() => updateJsonFile('.angular-cli.json', configJson => {
+      const app = configJson['apps'][0];
+      app['outDir'] = 'dist';
+    })
+
     // This asset should also fail from reading from outside the project.
     .then(() => updateJsonFile('.angular-cli.json', configJson => {
       const app = configJson['apps'][0];