fix: align CREATE and ALTER index option boundaries

src/main/java/net/sf/jsqlparser/statement/create/table/TableOption.java

@@ -21,7 +21,7 @@
 public class TableOption implements Serializable {
 
     public enum Kind {
-        ENGINE, CHARACTER_SET, COLLATE, COMMENT, AUTO_INCREMENT, STATS_AUTO_RECALC, STATS_PERSISTENT, STATS_SAMPLE_PAGES, UNION, ENCRYPTION, PASSWORD, DATA_DIRECTORY, INDEX_DIRECTORY, OTHER
+        ENGINE, CHARACTER_SET, COLLATE, COMMENT, AUTO_INCREMENT, STATS_AUTO_RECALC, STATS_PERSISTENT, STATS_SAMPLE_PAGES, UNION, ENCRYPTION, PASSWORD, DATA_DIRECTORY, INDEX_DIRECTORY, ENGINE_ATTRIBUTE, SECONDARY_ENGINE_ATTRIBUTE, OTHER
     }
 
     private Kind kind = Kind.OTHER;

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

@@ -1555,9 +1555,13 @@ public class CCJSqlParser extends AbstractJSqlParser<CCJSqlParser> {
                 || "STATS_SAMPLE_PAGES".equalsIgnoreCase(name);
     }
 
+    private boolean isMySqlEngineAttributeAhead() {
+        return isKeywordAhead("ENGINE_ATTRIBUTE") || isKeywordAhead("SECONDARY_ENGINE_ATTRIBUTE");
+    }
+
     private boolean isMySqlScalarTableOptionAhead() {
         int kind = getToken(1).kind;
-        return kind == K_ENCRYPTION || kind == K_PASSWORD || kind == K_AUTO_INCREMENT
+        return isMySqlEngineAttributeAhead() || kind == K_ENCRYPTION || kind == K_PASSWORD || kind == K_AUTO_INCREMENT
                 || (kind == K_DATA || kind == K_INDEX) && getToken(2).kind == K_DIRECTORY;
     }
 
@@ -15237,6 +15241,9 @@ TableOption MySqlTableOption(): {
                     "Expected DEFAULT, 0, or 1 for " + name);
         }
         |
+        LOOKAHEAD({ isMySqlScalarTableOptionAhead() }) option=MySqlScalarTableOption()
+        { return option; }
+        |
         tk=<K_ENGINE> {
             name = tk.image;
             kind = TableOption.Kind.ENGINE;
@@ -15271,9 +15278,6 @@ TableOption MySqlTableOption(): {
         }
         [ "=" { useEquals = true; } ]
         value=MySqlTableOptionValue()
-        |
-        LOOKAHEAD({ isMySqlScalarTableOptionAhead() }) option=MySqlScalarTableOption()
-        { return option; }
     )
     {
         option = new TableOption(kind, name, value, useEquals);
@@ -15301,6 +15305,10 @@ TableOption MySqlScalarTableOption():
             | <K_PASSWORD> { name = "PASSWORD"; kind = TableOption.Kind.PASSWORD; }
             | <K_DATA> <K_DIRECTORY> { name = "DATA DIRECTORY"; kind = TableOption.Kind.DATA_DIRECTORY; }
             | <K_INDEX> <K_DIRECTORY> { name = "INDEX DIRECTORY"; kind = TableOption.Kind.INDEX_DIRECTORY; }
+            | LOOKAHEAD({ isMySqlEngineAttributeAhead() }) token=<S_IDENTIFIER> {
+                name = token.image.toUpperCase(Locale.ROOT);
+                kind = TableOption.Kind.valueOf(name);
+            }
         )
         [ "=" { useEquals = true; } ] token=<S_CHAR_LITERAL> { value = token.image; }
     )
@@ -16676,7 +16684,8 @@ void IndexOptionList(List<String> list) :
 {}
 {
     (
-       LOOKAHEAD(2) IndexOption(list)
+       LOOKAHEAD(2, { !(getToken(1).kind == K_USING && getToken(2).kind == K_INDEX) })
+       IndexOption(list)
     )*
 }
 
@@ -16697,9 +16706,13 @@ void IndexOption(List<String> list) :
     Token tk2 = null;
     String sk1 = null;
     boolean useEqual = false;
+    TableOption attribute;
 }
 {
     (
+      LOOKAHEAD({ isMySqlEngineAttributeAhead() }) attribute=MySqlScalarTableOption()
+      { list.addAll(attribute.getTokens()); }
+    |
       tk1=<K_KEY_BLOCK_SIZE> ["=" { useEqual = true; } ] tk2=<S_LONG>
       {
         list.add("KEY_BLOCK_SIZE" +  (useEqual ? " = " : "") + tk2.image);

src/test/java/net/sf/jsqlparser/statement/alter/IndexOptionBoundaryTest.java

@@ -0,0 +1,75 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2026 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.statement.alter;
+
+import static org.junit.jupiter.api.Assertions.*;
+import net.sf.jsqlparser.JSQLParserException;
+import net.sf.jsqlparser.parser.AbstractJSqlParser.Dialect;
+import net.sf.jsqlparser.parser.CCJSqlParserUtil;
+import net.sf.jsqlparser.statement.Statement;
+import net.sf.jsqlparser.statement.create.table.Index;
+import net.sf.jsqlparser.statement.create.table.TableOption;
+import net.sf.jsqlparser.util.deparser.StatementDeParser;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+class IndexOptionBoundaryTest {
+    @ParameterizedTest
+    @ValueSource(strings = {"UNIQUE", "PRIMARY KEY"})
+    void tablespaceBelongsToConstraintOptions(String key) throws JSQLParserException {
+        Alter alter = (Alter) parse("ALTER TABLE t ADD CONSTRAINT k " + key
+                + " (id) USING INDEX TABLESPACE pg_default DEFERRABLE", Dialect.POSTGRESQL);
+        Index index = alter.getAlterExpressions().get(0).getIndex();
+        assertEquals("pg_default", index.getTableSpace());
+        assertNull(index.getUsing());
+        assertTrue(index.getConstraintAttributes().getDeferrable());
+        index.setTableSpace("other_space");
+        assertEquals("ALTER TABLE t ADD CONSTRAINT k " + key
+                + " (id) USING INDEX TABLESPACE other_space DEFERRABLE", alter.toString());
+        assertRoundTrip(alter, Dialect.POSTGRESQL);
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"SECONDARY_ENGINE_ATTRIBUTE = '{}'",
+            "SECONDARY_ENGINE_ATTRIBUTE '{\"key\": \"value\"}'",
+            "SECONDARY_ENGINE_ATTRIBUTE = '{}' VISIBLE COMMENT 'index'"})
+    void mysqlAddIndexAttributes(String options) throws JSQLParserException {
+        Alter alter = (Alter) parse("ALTER TABLE t ADD INDEX ix (id) " + options, Dialect.MYSQL);
+        assertEquals("ix", alter.getAlterExpressions().get(0).getIndex().getName());
+        assertEquals("ALTER TABLE t ADD  INDEX ix (id) " + options, alter.toString());
+        assertRoundTrip(alter, Dialect.MYSQL);
+    }
+
+    @Test
+    void sharedTableAttributeRemainsMutable() throws JSQLParserException {
+        Alter alter =
+                (Alter) parse("ALTER TABLE t SECONDARY_ENGINE_ATTRIBUTE = '{}'", Dialect.MYSQL);
+        AlterExpressionTableOption action =
+                (AlterExpressionTableOption) alter.getAlterExpressions().get(0);
+        TableOption option = action.getStructuredTableOption();
+        assertEquals(TableOption.Kind.SECONDARY_ENGINE_ATTRIBUTE, option.getKind());
+        option.setValue("'{\"key\":1}'");
+        assertEquals("ALTER TABLE t SECONDARY_ENGINE_ATTRIBUTE = '{\"key\":1}'", alter.toString());
+        assertRoundTrip(alter, Dialect.MYSQL);
+    }
+
+    private static Statement parse(String sql, Dialect dialect) throws JSQLParserException {
+        return CCJSqlParserUtil.parse(sql, p -> p.withDialect(dialect));
+    }
+
+    private static void assertRoundTrip(Statement statement, Dialect dialect)
+            throws JSQLParserException {
+        StringBuilder sql = new StringBuilder();
+        statement.accept(new StatementDeParser(sql), null);
+        assertEquals(statement.toString(), sql.toString());
+        assertEquals(statement.toString(), parse(sql.toString(), dialect).toString());
+    }
+}