Reland: Support multi-line environment variables

A standard Fedora install comes with 2 multiple line environment variables.
Since `env` was previously split by '\n' this would break them, causing
errors in the output pane and in terminals launched through the file
explorer (see #3495).

The original commit didn't work on OSX since `env` does not support the --null
arg. This version can fail if a command line arg's 1+th line looks like an
environment variable. There is no easy way to prevent this since `process.env`
cannot be leveraged. Since the likelyhood of this happening is small, plus the
chance of it causing any significant issue is also small it's a reasonable
compromise for the time being.

Fixes #3928
Fixes #4672

src/vs/base/node/env.ts

@@ -35,23 +35,45 @@ export function getUserEnvironment(): TPromise<IEnv> {
 				return c({});
 			}
 
-			let result: IEnv = Object.create(null);
+			c(parseEnvOutput(buffer));
+		});
+	});
+}
 
-			buffer.split('\n').forEach(line => {
-				let pos = line.indexOf('=');
-				if (pos > 0) {
-					let key = line.substring(0, pos);
-					let value = line.substring(pos + 1);
+/**
+ * Parse output from `env`, attempting to retain any multiple-line variables.
+ */
+export function parseEnvOutput(output): IEnv {
+	let result: IEnv = Object.create(null);
+	let vars = output.split('\n');
 
-					if (!key || typeof result[key] === 'string') {
-						return;
-					}
+	// Rejoin lines to the preceeding line if it doesn't look like the line is a new variable
+	let current = 0;
+	for (let i = 1; i < vars.length; i++) {
+		if (vars[i].match(/^[\w_][\w\d_]*=/) === null) {
+			vars[current] += `\n${vars[i]}`;
+		} else {
+			vars[++current] = vars[i];
+		}
+	}
 
-					result[key] = value;
-				}
-			});
+	// Trim any remaining vars that had been moved
+	vars.length = current + 1;
 
-			c(result);
-		});
+	// Turn the array into a map
+	vars.forEach(line => {
+		let pos = line.indexOf('=');
+		if (pos > 0) {
+			let key = line.substring(0, pos);
+			let value = line.substring(pos + 1);
+
+			if (!key || typeof result[key] === 'string') {
+				return;
+			}
+
+			result[key] = value;
+		}
 	});
+
+	return result;
 }

src/vs/base/test/node/env.test.ts

+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+import * as assert from 'assert';
+import env = require('vs/base/node/env');
+
+suite('Env', () => {
+	test('Parses multi-line environment variables at end of env', function(done: () => void) {
+		let vars = env.parseEnvOutput("a=first\nb=multiple\nlines");
+
+		assert.equal(Object.keys(vars).length, 2);
+		assert.equal(vars['a'], "first");
+		assert.equal(vars['b'], "multiple\nlines");
+
+		done();
+	});
+
+	test('Parses multi-line environment variables at start of env', function(done: () => void) {
+		let vars = env.parseEnvOutput("a=multiple\nlines\nb=second");
+
+		assert.equal(Object.keys(vars).length, 2);
+		assert.equal(vars['a'], "multiple\nlines");
+		assert.equal(vars['b'], "second");
+
+		done();
+	});
+
+	test('Parses complex multi-line environment variables', function(done: () => void) {
+		let vars = env.parseEnvOutput("a=1\nb=\n23 =4\n_5c=56\n d=7\nE =8");
+
+		assert.equal(Object.keys(vars).length, 3);
+		assert.equal(vars['a'], "1");
+		assert.equal(vars['b'], "\n23 =4");
+		assert.equal(vars['_5c'], "56\n d=7\nE =8");
+
+		done();
+	});
+});
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