findExecutable should check PATH in a case-insensitive way

Fix #109863

src/vs/base/common/objects.ts

@@ -220,3 +220,9 @@ export function distinct(base: obj, target: obj): obj {
 
 	return result;
 }
+
+export function getCaseInsensitive(target: obj, key: string): any {
+	const lowercaseKey = key.toLowerCase();
+	const equivalentKey = Object.keys(target).find(k => k.toLowerCase() === lowercaseKey);
+	return equivalentKey ? target[equivalentKey] : target[key];
+}

src/vs/base/test/common/objects.test.ts

@@ -212,4 +212,17 @@ suite('Objects', () => {
 		diff = objects.distinct(base, obj);
 		assert.deepEqual(diff, obj);
 	});
-});
\ No newline at end of file
+
+	test('getCaseInsensitive', () => {
+		const obj1 = {
+			lowercase: 123,
+			mIxEdCaSe: 456
+		};
+
+		assert.equal(obj1.lowercase, objects.getCaseInsensitive(obj1, 'lowercase'));
+		assert.equal(obj1.lowercase, objects.getCaseInsensitive(obj1, 'lOwErCaSe'));
+
+		assert.equal(obj1.mIxEdCaSe, objects.getCaseInsensitive(obj1, 'MIXEDCASE'));
+		assert.equal(obj1.mIxEdCaSe, objects.getCaseInsensitive(obj1, 'mixedcase'));
+	});
+});

src/vs/workbench/contrib/terminal/node/terminalEnvironment.ts

@@ -7,6 +7,7 @@ import { IProcessEnvironment, isLinux, isMacintosh, isWindows } from 'vs/base/co
 import { readFile, exists } from 'vs/base/node/pfs';
 import * as path from 'vs/base/common/path';
 import { isString } from 'vs/base/common/types';
+import { getCaseInsensitive } from 'vs/base/common/objects';
 
 let mainProcessParentEnv: IProcessEnvironment | undefined;
 
@@ -94,8 +95,9 @@ export async function findExecutable(command: string, cwd?: string, paths?: stri
 		const fullPath = path.join(cwd, command);
 		return await exists(fullPath) ? fullPath : undefined;
 	}
-	if (paths === undefined && isString(env.PATH)) {
-		paths = env.PATH.split(path.delimiter);
+	const envPath = getCaseInsensitive(env, 'PATH');
+	if (paths === undefined && isString(envPath)) {
+		paths = envPath.split(path.delimiter);
 	}
 	// No PATH environment. Make path absolute to the cwd.
 	if (paths === undefined || paths.length === 0) {