[2372] handle unbalanced parentheses.

src/lib/dns/master_lexer.cc

@@ -230,7 +230,11 @@ Start::handle(MasterLexer& lexer, MasterLexer::Options& options) const {
             ++getLexerImpl(lexer)->paren_count_;
             continue;
         } else if (c == ')') {
-            // TBD: unbalanced case
+            getLexerImpl(lexer)->last_was_eol_ = false;
+            if (getLexerImpl(lexer)->paren_count_ == 0) {
+                getLexerImpl(lexer)->token_ = Token(Token::UNBALANCED_PAREN);
+                return (NULL);
+            }
             --getLexerImpl(lexer)->paren_count_;
             if (getLexerImpl(lexer)->paren_count_ == 0) {
                 options = getLexerImpl(lexer)->orig_options_;

src/lib/dns/tests/master_lexer_state_unittest.cc

@@ -142,7 +142,6 @@ TEST_F(MasterLexerStateTest, parentheses) {
 
 TEST_F(MasterLexerStateTest, nestedParentheses) {
     // This is an unusual, but allowed (in this implementation) case.
-
     ss << "(a(b)c)";
     EXPECT_EQ(&s_string, s_start.handle(lexer, options)); // consume '(a'
     EXPECT_EQ(&s_string, s_start.handle(lexer, options)); // consume '(b'
@@ -162,4 +161,22 @@ TEST_F(MasterLexerStateTest, nestedParentheses) {
     EXPECT_TRUE((options & MasterLexer::INITIAL_WS) != 0);
 }
 
+TEST_F(MasterLexerStateTest, unbalancedParentheses) {
+    // Only closing paren is provided.  We prepend a \n to check if it's
+    // correctly canceled after detecting the error.
+    ss << "\n)";
+
+    EXPECT_EQ(s_null, s_start.handle(lexer, options)); // consume '\n'
+    EXPECT_TRUE(s_start.wasLastEOL(lexer)); // this \n was remembered
+
+    // Now checking ')'.  The result should be error, count shouldn't be
+    // changed.  "last EOL" should be canceled.
+    EXPECT_EQ(0, s_start.getParenCount(lexer));
+    EXPECT_EQ(s_null, s_start.handle(lexer, options));
+    EXPECT_EQ(0, s_start.getParenCount(lexer));
+    ASSERT_EQ(Token::ERROR, s_start.getToken(lexer).getType());
+    EXPECT_EQ(Token::UNBALANCED_PAREN, s_start.getToken(lexer).getErrorCode());
+    EXPECT_FALSE(s_start.wasLastEOL(lexer));
+}
+
 }