Fix quoting logic to escape special characters in exec path (#890)

fixes microsoft/vscode-python-environments#876

Author: eleanorjboyd

src/features/execution/execUtils.ts

@@ -1,8 +1,14 @@
 export function quoteStringIfNecessary(arg: string): string {
-    if (arg.indexOf(' ') >= 0 && !(arg.startsWith('"') && arg.endsWith('"'))) {
-        return `"${arg}"`;
+    // Always return if already quoted to avoid double-quoting
+    if (arg.startsWith('"') && arg.endsWith('"')) {
+        return arg;
     }
-    return arg;
+
+    // Quote if contains common shell special characters that are problematic across multiple shells
+    // Includes: space, &, |, <, >, ;, ', ", `, (, ), [, ], {, }, $
+    const needsQuoting = /[\s&|<>;'"`()\[\]{}$]/.test(arg);
+
+    return needsQuoting ? `"${arg}"` : arg;
 }
 
 export function quoteArgs(args: string[]): string[] {