fix: require end of input when parsing a single statement (#2733)

- `Statement()` lost its `<EOF>` validation in 063d244 ("feat: return any `UnsupportedStatement`
  content"), which replaced `[ <ST_SEMICOLON> ] <EOF>` with `( <ST_SEMICOLON> | <EOF> )`; ever
  since, input holding more than one statement silently returned a truncated AST instead of
  failing, so callers such as PageHelper's count SQL parser reuse the full parameter mappings
  against a partial statement
- `ST_SEMICOLON` also matches blank line runs such as `"\n\n\n"`, which makes the silent
  truncation reachable from ordinary formatted SQL that has no semicolon at all
- restore the pre-063d2442 contract with `( <ST_SEMICOLON> )* <EOF>` in both `Statement()`
  branches, keeping trailing separators and comments legal while rejecting any unconsumed
  statement
- `Statements()` (which kept its trailing `<EOF>`) and `SingleStatement()` are untouched; walking
  a script statement by statement stays the incremental API's job
- rewrite the routine boundary test that asserted the lenient behaviour to drive the parser with
  `SingleStatement()`, which is how `streamStatements` consumes multi statement scripts

Author: MoshiCoCo

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -3293,13 +3293,14 @@ Statement Statement() #Statement:
                            ifElseStatement.setUsingSemicolonForIfStatement(true);
                      }
                  ]
+                 <EOF>
             )
             |
             (
                 (stm = SingleStatement()
                     | stm = Block())
 
-                ( <ST_SEMICOLON> | <EOF> )
+                ( <ST_SEMICOLON> )* <EOF>
             )
             |
             LOOKAHEAD( { stm==null && getAsBoolean(Feature.allowUnsupportedStatements) } ) stm = UnsupportedStatement()

src/test/java/net/sf/jsqlparser/parser/CCJSqlParserUtilTest.java

@@ -525,6 +525,36 @@ void testParseEmpty() {
         assertThrows(JSQLParserException.class, () -> CCJSqlParserUtil.parse((String) null));
     }
 
+    @Test
+    void testParseRejectsUnconsumedInput() throws Exception {
+        // "\n\n\n" separates statements exactly like ";" does, so both inputs below hold
+        // two statements; a single statement parse must not silently return the first only
+        String newlineSeparated = "SELECT a FROM dual WHERE x = ?\n\n\n AND y = ?";
+        String semicolonSeparated = "SELECT a FROM dual; SELECT b FROM dual";
+
+        assertThrows(JSQLParserException.class, () -> CCJSqlParserUtil.parse(newlineSeparated));
+        assertThrows(JSQLParserException.class, () -> CCJSqlParserUtil.parse(semicolonSeparated));
+        assertThrows(ParseException.class,
+                () -> CCJSqlParserUtil.newParser(newlineSeparated).Statement());
+        assertThrows(JSQLParserException.class, () -> CCJSqlParserUtil
+                .parse(new ByteArrayInputStream(
+                        newlineSeparated.getBytes(StandardCharsets.UTF_8))));
+        assertThrows(JSQLParserException.class, () -> CCJSqlParserUtil.parseAST(newlineSeparated));
+
+        // trailing separators and comments do not make a statement incomplete
+        assertEquals("SELECT a FROM dual",
+                CCJSqlParserUtil.parse("SELECT a FROM dual;").toString());
+        assertEquals("SELECT a FROM dual",
+                CCJSqlParserUtil.parse("SELECT a FROM dual\n\n\n").toString());
+        assertEquals("SELECT a FROM dual",
+                CCJSqlParserUtil.parse("SELECT a FROM dual -- done").toString());
+
+        // the multi statement API keeps working
+        assertEquals(2, CCJSqlParserUtil.parseStatements(semicolonSeparated).size());
+        assertEquals(3, CCJSqlParserUtil.parseStatements(
+                "SELECT * FROM DUAL\n\n\nSELECT * FROM DUAL\n\n\n\nSELECT * FROM dual").size());
+    }
+
     @Test
     void testSingleStatementWithEmptyLines() throws JSQLParserException {
         String sqlStr = "update shop_info set title=?,\n"

src/test/java/net/sf/jsqlparser/statement/create/SqlRoutineBodyBoundaryTest.java

@@ -107,12 +107,16 @@ void preservesRoutineBodyAndFollowingStatement(Dialect dialect, String sql) thro
     }
 
     @Test
-    void directStatementParserLeavesFollowingStatementAvailable() throws Exception {
+    void directSingleStatementParserLeavesFollowingStatementAvailable() throws Exception {
+        // walking a script statement by statement is SingleStatement()'s job; Statement() reads
+        // the input as exactly one statement and rejects whatever is left over
         CCJSqlParser parser = parser("CREATE FUNCTION f() RETURNS int LANGUAGE SQL RETURN 1; "
                 + FOLLOWING + ";", Dialect.POSTGRESQL);
-        assertThat(parser.Statement()).isInstanceOf(CreateFunction.class);
+        assertThat(parser.SingleStatement()).isInstanceOf(CreateFunction.class);
+        assertThat(parser.getNextToken().kind).isEqualTo(CCJSqlParserConstants.ST_SEMICOLON);
         assertThat(parser.getToken(1).kind).isEqualTo(CCJSqlParserConstants.K_SELECT);
-        assertThat(parser.Statement().toString()).isEqualTo(FOLLOWING);
+        assertThat(parser.SingleStatement().toString()).isEqualTo(FOLLOWING);
+        assertThat(parser.getNextToken().kind).isEqualTo(CCJSqlParserConstants.ST_SEMICOLON);
         assertThat(parser.getToken(1).kind).isEqualTo(CCJSqlParserConstants.EOF);
     }