Fix for Bug#23204652, Bug#71929 (18346501) and Bug#103612 (32902019).

Fix for Bug#23204652, CURSOR POSITIONING API'S DOESNOT CHECK THE VALIDITY OF RESULTSET.
Fix for Bug#71929 (18346501), Prefixing query with double comments cancels query DML validation.
Fix for Bug#103612 (32902019), Incorrectly identified WITH...SELECT as unsafe for read-only connections.

Author: fjssilva

CHANGES

@@ -3,6 +3,12 @@
 
 Version 8.0.27
 
+  - Fix for Bug#103612 (32902019), Incorrectly identified WITH...SELECT as unsafe for read-only connections.
+
+  - Fix for Bug#71929 (18346501), Prefixing query with double comments cancels query DML validation.
+
+  - Fix for Bug#23204652, CURSOR POSITIONING API'S DOESNOT CHECK THE VALIDITY OF RESULTSET.
+
   - Fix for Bug#28725534, MULTI HOST CONNECTION WOULD BLOCK IN CONNECTION POOLING.
 
   - Fix for Bug#95139 (29807572), CACHESERVERCONFIGURATION APPEARS TO THWART CHARSET DETECTION.

src/build/java/instrumentation/TranslateExceptions.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2020, Oracle and/or its affiliates.
+ * Copyright (c) 2015, 2021, Oracle and/or its affiliates.
  *
  * This program is free software; you can redistribute it and/or modify it under
  * the terms of the GNU General Public License, version 2.0, as published by the
@@ -292,7 +292,7 @@ public static void main(String[] args) throws Exception {
         /*
          * java.sql.PreparedStatement extends java.sql.Statement (java.sql.Statement extends java.sql.Wrapper)
          */
-        // com.mysql.cj.jdbc.PreparedStatement extends com.mysql.cj.jdbc.StatementImpl implements java.sql.PreparedStatement
+        // com.mysql.cj.jdbc.ClientPreparedStatement extends com.mysql.cj.jdbc.StatementImpl implements java.sql.PreparedStatement
         clazz = pool.get(ClientPreparedStatement.class.getName());
         instrumentJdbcMethods(clazz, java.sql.PreparedStatement.class, false, EXCEPTION_INTERCEPTOR_GETTER);
         instrumentJdbcMethods(clazz, JdbcStatement.class, true, EXCEPTION_INTERCEPTOR_GETTER);
@@ -318,7 +318,6 @@ public static void main(String[] args) throws Exception {
         catchRuntimeException(clazz, clazz.getDeclaredMethod("getParameterBindings", new CtClass[] {}), EXCEPTION_INTERCEPTOR_GETTER);
         catchRuntimeException(clazz, clazz.getDeclaredMethod("initializeFromParseInfo", new CtClass[] {}), EXCEPTION_INTERCEPTOR_GETTER);
         catchRuntimeException(clazz, clazz.getDeclaredMethod("isNull", new CtClass[] { CtClass.intType }), EXCEPTION_INTERCEPTOR_GETTER);
-        catchRuntimeException(clazz, clazz.getDeclaredMethod("isSelectQuery", new CtClass[] {}), EXCEPTION_INTERCEPTOR_GETTER);
         catchRuntimeException(clazz, clazz.getDeclaredMethod("prepareBatchedInsertSQL", new CtClass[] { ctJdbcConnection, CtClass.intType }),
                 EXCEPTION_INTERCEPTOR_GETTER);
         catchRuntimeException(clazz,
@@ -328,7 +327,7 @@ public static void main(String[] args) throws Exception {
         clazz.writeFile(args[0]);
 
         /*
-         * com.mysql.cj.jdbc.ServerPreparedStatement extends PreparedStatement
+         * com.mysql.cj.jdbc.ServerPreparedStatement extends ClientPreparedStatement
          */
         clazz = pool.get(ServerPreparedStatement.class.getName());
         instrumentJdbcMethods(clazz, java.sql.PreparedStatement.class, false, EXCEPTION_INTERCEPTOR_GETTER);

src/main/core-api/java/com/mysql/cj/ParseInfo.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, version 2.0, as published by the
+ * Free Software Foundation.
+ *
+ * This program is also distributed with certain software (including but not
+ * limited to OpenSSL) that is licensed under separate terms, as designated in a
+ * particular file or component or in included license documentation. The
+ * authors of MySQL hereby grant you an additional permission to link the
+ * program and your derivative works with the separately licensed software that
+ * they have included with MySQL.
+ *
+ * Without limiting anything contained in the foregoing, this file, which is
+ * part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
+ * version 1.0, a copy of which can be found at
+ * http://oss.oracle.com/licenses/universal-foss-exception.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0,
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
+ */
+
+package com.mysql.cj;
+
+/**
+ * The possible return types from executing queries.
+ */
+public enum QueryReturnType {
+    PRODUCES_RESULT_SET, MAY_PRODUCE_RESULT_SET, DOES_NOT_PRODUCE_RESULT_SET, NONE;
+}

src/main/core-api/java/com/mysql/cj/QueryReturnType.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2020, Oracle and/or its affiliates.
+ * Copyright (c) 2016, 2021, Oracle and/or its affiliates.
  *
  * This program is free software; you can redistribute it and/or modify it under
  * the terms of the GNU General Public License, version 2.0, as published by the
@@ -49,6 +49,7 @@
 import com.mysql.cj.exceptions.ExceptionFactory;
 import com.mysql.cj.exceptions.UnsupportedConnectionStringException;
 import com.mysql.cj.exceptions.WrongArgumentException;
+import com.mysql.cj.util.SearchMode;
 import com.mysql.cj.util.StringUtils;
 
 /**
@@ -178,7 +179,7 @@ private void parseAuthoritySection() {
         }
 
         List<String> authoritySegments = StringUtils.split(this.authority, HOSTS_SEPARATOR, HOSTS_LIST_OPENING_MARKERS, HOSTS_LIST_CLOSING_MARKERS, true,
-                StringUtils.SEARCH_MODE__MRK_WS);
+                SearchMode.__MRK_WS);
         for (String hi : authoritySegments) {
             parseAuthoritySegment(hi);
         }
@@ -354,7 +355,7 @@ private List<HostInfo> buildHostInfoResortingToSubHostsListParser(String user, S
         if (matcher.matches()) {
             String hosts = matcher.group("hosts");
             List<String> hostsList = StringUtils.split(hosts, HOSTS_SEPARATOR, HOSTS_LIST_OPENING_MARKERS, HOSTS_LIST_CLOSING_MARKERS, true,
-                    StringUtils.SEARCH_MODE__MRK_WS);
+                    SearchMode.__MRK_WS);
             // One single element could, in fact, be an IPv6 stripped from its delimiters.
             boolean maybeIPv6 = hostsList.size() == 1 && hostsList.get(0).matches("(?i)^[\\dabcdef:]+$");
             List<HostInfo> hostInfoList = new ArrayList<>();

src/main/core-api/java/com/mysql/cj/conf/ConnectionUrlParser.java

@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, version 2.0, as published by the
+ * Free Software Foundation.
+ *
+ * This program is also distributed with certain software (including but not
+ * limited to OpenSSL) that is licensed under separate terms, as designated in a
+ * particular file or component or in included license documentation. The
+ * authors of MySQL hereby grant you an additional permission to link the
+ * program and your derivative works with the separately licensed software that
+ * they have included with MySQL.
+ *
+ * Without limiting anything contained in the foregoing, this file, which is
+ * part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
+ * version 1.0, a copy of which can be found at
+ * http://oss.oracle.com/licenses/universal-foss-exception.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0,
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
+ */
+
+package com.mysql.cj.util;
+
+import java.util.Collections;
+import java.util.EnumSet;
+import java.util.Set;
+
+/**
+ * Search mode flags enumeration. Primarily used by {@link StringInspector}.
+ */
+public enum SearchMode {
+    /**
+     * Allow backslash escapes.
+     */
+    ALLOW_BACKSLASH_ESCAPE,
+    /**
+     * Skip between markers (quoted text, quoted identifiers, text between parentheses).
+     */
+    SKIP_BETWEEN_MARKERS,
+    /**
+     * Skip between block comments ("/* text... *\/") but not between hint blocks.
+     */
+    SKIP_BLOCK_COMMENTS,
+    /**
+     * Skip line comments ("-- text...", "# text...").
+     */
+    SKIP_LINE_COMMENTS,
+    /**
+     * Skip MySQL specific markers ("/*![12345]" and "*\/") but not their contents.
+     */
+    SKIP_MYSQL_MARKERS,
+    /**
+     * Skip hint blocks ("/*+ text... *\/").
+     */
+    SKIP_HINT_BLOCKS,
+    /**
+     * Skip white space.
+     */
+    SKIP_WHITE_SPACE,
+    /**
+     * Dummy search mode. Does nothing.
+     */
+    VOID;
+
+    /*
+     * Convenience EnumSets for several SearchMode combinations
+     */
+
+    /**
+     * Full search mode: allow backslash escape, skip between markers, skip block comments, skip line comments, skip MySQL markers, skip hint blocks and skip
+     * white space.
+     * This is technically equivalent to __BSE_MRK_COM_MYM_HNT_WS.
+     */
+    public static final Set<SearchMode> __FULL = Collections.unmodifiableSet(EnumSet.allOf(SearchMode.class));
+
+    /**
+     * Search mode: allow backslash escape, skip between markers, skip block comments, skip line comments, skip MySQL markers, skip hint blocks and skip
+     * white space.
+     */
+    public static final Set<SearchMode> __BSE_MRK_COM_MYM_HNT_WS = Collections.unmodifiableSet(EnumSet.of(ALLOW_BACKSLASH_ESCAPE, SKIP_BETWEEN_MARKERS,
+            SKIP_BLOCK_COMMENTS, SKIP_LINE_COMMENTS, SKIP_MYSQL_MARKERS, SKIP_HINT_BLOCKS, SKIP_WHITE_SPACE));
+
+    /**
+     * Search mode: skip between markers, skip block comments, skip line comments, skip MySQL markers, skip hint blocks and skip white space.
+     */
+    public static final Set<SearchMode> __MRK_COM_MYM_HNT_WS = Collections
+            .unmodifiableSet(EnumSet.of(SKIP_BETWEEN_MARKERS, SKIP_BLOCK_COMMENTS, SKIP_LINE_COMMENTS, SKIP_MYSQL_MARKERS, SKIP_HINT_BLOCKS, SKIP_WHITE_SPACE));
+
+    /**
+     * Search mode: allow backslash escape, skip block comments, skip line comments, skip MySQL markers, skip hint blocks and skip white space.
+     */
+    public static final Set<SearchMode> __BSE_COM_MYM_HNT_WS = Collections.unmodifiableSet(
+            EnumSet.of(ALLOW_BACKSLASH_ESCAPE, SKIP_BLOCK_COMMENTS, SKIP_LINE_COMMENTS, SKIP_MYSQL_MARKERS, SKIP_HINT_BLOCKS, SKIP_WHITE_SPACE));
+
+    /**
+     * Search mode: skip block comments, skip line comments, skip MySQL markers, skip hint blocks and skip white space.
+     */
+    public static final Set<SearchMode> __COM_MYM_HNT_WS = Collections
+            .unmodifiableSet(EnumSet.of(SKIP_BLOCK_COMMENTS, SKIP_LINE_COMMENTS, SKIP_MYSQL_MARKERS, SKIP_HINT_BLOCKS, SKIP_WHITE_SPACE));
+
+    /**
+     * Search mode: allow backslash escape, skip between markers and skip white space.
+     */
+    public static final Set<SearchMode> __BSE_MRK_WS = Collections.unmodifiableSet(EnumSet.of(ALLOW_BACKSLASH_ESCAPE, SKIP_BETWEEN_MARKERS, SKIP_WHITE_SPACE));
+
+    /**
+     * Search mode: skip between markers and skip white space.
+     */
+    public static final Set<SearchMode> __MRK_WS = Collections.unmodifiableSet(EnumSet.of(SKIP_BETWEEN_MARKERS, SKIP_WHITE_SPACE));
+
+    /**
+     * Empty search mode.
+     * There must be at least one element so that the Set may be later duplicated if needed.
+     */
+    public static final Set<SearchMode> __NONE = Collections.unmodifiableSet(EnumSet.of(VOID));
+}