Add enclosing group to alternations in globs

Fixes BurntSushi#391.

globset/src/glob.rs

@@ -659,9 +659,18 @@ impl Tokens {
                     for pat in patterns {
                         let mut altre = String::new();
                         self.tokens_to_regex(options, &pat, &mut altre);
-                        parts.push(altre);
+                        if !altre.is_empty() {
+                            parts.push(altre);
+                        }
+                    }
+
+                    // It is possible to have an empty set in which case the
+                    // resulting alternation '()' would be an error.
+                    if !parts.is_empty() {
+                        re.push('(');
+                        re.push_str(&parts.join("|"));
+                        re.push(')');
                     }
-                    re.push_str(&parts.join("|"));
                 }
             }
         }

tests/tests.rs

@@ -1326,6 +1326,27 @@ fn regression_270() {
     assert_eq!(lines, path("foo:-test\n"));
 }
 
+// See: https://github.com/BurntSushi/ripgrep/issues/391
+#[test]
+fn regression_391() {
+    let wd = WorkDir::new("regression_391");
+    wd.create_dir(".git");
+    wd.create("lock", "");
+    wd.create("bar.py", "");
+    wd.create(".git/packed-refs", "");
+    wd.create(".git/description", "");
+
+    let mut cmd = wd.command();
+    cmd.arg("--no-ignore").arg("--hidden").arg("--follow").arg("--files")
+        .arg("--glob")
+        .arg("!{.git,node_modules,plugged}/**")
+        .arg("--glob")
+        .arg("*.{js,json,php,md,styl,scss,sass,pug,html,config,py,cpp,c,go,hs}");
+
+    let lines: String = wd.stdout(&mut cmd);
+    assert_eq!(lines, "bar.py\n");
+}
+
 #[test]
 fn type_list() {
     let wd = WorkDir::new("type_list");