Fix for Bug#101389 (32089018), GETWARNINGS SHOULD CHECK WARNING COUNT

BEFORE SENDING SHOW.

Author: soklakov

CHANGES

@@ -3,6 +3,8 @@
 
 Version 8.0.28
 
+  - Fix for Bug#101389 (32089018), GETWARNINGS SHOULD CHECK WARNING COUNT BEFORE SENDING SHOW.
+
   - Fix for Bug#33488091, Remove all references to xdevapi.useAsyncProtocol from properties and code.
 
   - WL#14805, Remove support for TLS 1.0 and 1.1.

src/main/protocol-impl/java/com/mysql/cj/protocol/a/NativeProtocol.java

@@ -1935,7 +1935,7 @@ public void unsetStreamingData(ResultsetRows streamer) {
     public void scanForAndThrowDataTruncation() {
         if (this.streamingData == null && this.propertySet.getBooleanProperty(PropertyKey.jdbcCompliantTruncation).getValue() && getWarningCount() > 0) {
             int warningCountOld = getWarningCount();
-            convertShowWarningsToSQLWarnings(getWarningCount(), true);
+            convertShowWarningsToSQLWarnings(true);
             setWarningCount(warningCountOld);
         }
     }
@@ -2085,14 +2085,16 @@ private StringBuilder appendResultSetSlashGStyle(StringBuilder appendTo, Results
      * If 'forTruncationOnly' is true, only looks for truncation warnings, and
      * actually throws DataTruncation as an exception.
      * 
-     * @param warningCountIfKnown
-     *            the warning count (if known), otherwise set it to 0.
      * @param forTruncationOnly
      *            if this method should only scan for data truncation warnings
      * 
      * @return the SQLWarning chain (or null if no warnings)
      */
-    public SQLWarning convertShowWarningsToSQLWarnings(int warningCountIfKnown, boolean forTruncationOnly) {
+    public SQLWarning convertShowWarningsToSQLWarnings(boolean forTruncationOnly) {
+        if (this.warningCount == 0) {
+            return null;
+        }
+
         SQLWarning currentWarning = null;
         ResultsetRows rows = null;
 
@@ -2106,7 +2108,7 @@ public SQLWarning convertShowWarningsToSQLWarnings(int warningCountIfKnown, bool
              */
             NativePacketPayload resultPacket = sendCommand(getCommandBuilder().buildComQuery(getSharedSendPacket(), "SHOW WARNINGS"), false, 0);
 
-            Resultset warnRs = readAllResults(-1, warningCountIfKnown > 99 /* stream large warning counts */, resultPacket, false, null,
+            Resultset warnRs = readAllResults(-1, this.warningCount > 99 /* stream large warning counts */, resultPacket, false, null,
                     new ResultsetFactory(Type.FORWARD_ONLY, Concurrency.READ_ONLY));
 
             int codeFieldIndex = warnRs.getColumnDefinition().findColumn("Code", false, 1) - 1;

src/main/user-impl/java/com/mysql/cj/jdbc/StatementImpl.java

@@ -1735,7 +1735,7 @@ public java.sql.SQLWarning getWarnings() throws SQLException {
                 return null;
             }
 
-            SQLWarning pendingWarningsFromServer = this.session.getProtocol().convertShowWarningsToSQLWarnings(0, false);
+            SQLWarning pendingWarningsFromServer = this.session.getProtocol().convertShowWarningsToSQLWarnings(false);
 
             if (this.warningChain != null) {
                 this.warningChain.setNextWarning(pendingWarningsFromServer);

src/test/java/testsuite/regression/ConnectionRegressionTest.java

@@ -9894,25 +9894,37 @@ public void testBug88227() throws Exception {
         props.setProperty(PropertyKey.sslMode.getKeyName(), SslMode.DISABLED.name());
         props.setProperty(PropertyKey.allowPublicKeyRetrieval.getKeyName(), "true");
         props.setProperty(PropertyKey.queryInterceptors.getKeyName(), Bug88227QueryInterceptor.class.getName());
+        Bug88227QueryInterceptor.enabled = false; // some warnings are expected here when running against old server versions
         java.sql.Connection testConn = getConnectionWithProps(props);
-        Bug88227QueryInterceptor.mayHaveWarnings = false;
+        Bug88227QueryInterceptor.enabled = true;
         testConn.getTransactionIsolation();
         testConn.isReadOnly();
         testConn.close();
     }
 
     public static class Bug88227QueryInterceptor extends BaseQueryInterceptor {
-        public static boolean mayHaveWarnings = true;
+        public static boolean enabled = false;
 
         @Override
         public <T extends Resultset> T preProcess(Supplier<String> sql, Query interceptedQuery) {
-            assertFalse(sql.get().contains("SHOW WARNINGS"), "Unexpected [SHOW WARNINGS] was issued");
+            if (enabled) {
+                assertFalse(sql.get().contains("SHOW WARNINGS"), "Unexpected [SHOW WARNINGS] was issued");
+            }
             return super.preProcess(sql, interceptedQuery);
         }
 
+        @Override
+        public <M extends Message> M preProcess(M queryPacket) {
+            if (enabled) {
+                String sql = StringUtils.toString(queryPacket.getByteBuffer(), 1, (queryPacket.getPosition() - 1));
+                assertFalse(sql.contains("SHOW WARNINGS"), "Unexpected [SHOW WARNINGS] was issued");
+            }
+            return super.preProcess(queryPacket);
+        }
+
         @Override
         public <T extends Resultset> T postProcess(Supplier<String> sql, Query interceptedQuery, T originalResultSet, ServerSession serverSession) {
-            if (!mayHaveWarnings) {
+            if (enabled) {
                 assertEquals(0, ((NativeSession) interceptedQuery.getSession()).getProtocol().getWarningCount(), "Warnings while executing [" + sql + "]");
             }
             return super.postProcess(sql, interceptedQuery, originalResultSet, serverSession);

src/test/java/testsuite/regression/StatementRegressionTest.java

@@ -142,11 +142,13 @@
 import com.mysql.cj.jdbc.result.ResultSetInternalMethods;
 import com.mysql.cj.log.Log;
 import com.mysql.cj.protocol.ColumnDefinition;
+import com.mysql.cj.protocol.Message;
 import com.mysql.cj.protocol.Resultset;
 import com.mysql.cj.protocol.ResultsetRows;
 import com.mysql.cj.protocol.ServerSession;
 import com.mysql.cj.protocol.a.NativeServerSession;
 import com.mysql.cj.util.LRUCache;
+import com.mysql.cj.util.StringUtils;
 import com.mysql.cj.util.TimeUtil;
 
 import testsuite.BaseQueryInterceptor;
@@ -11675,4 +11677,58 @@ public void testBug103612() throws Exception {
             testConn.close();
         } while ((useSPS = !useSPS) || (readOnly = !readOnly));
     }
+
+    /**
+     * Tests fix for Bug#101389 (32089018), GETWARNINGS SHOULD CHECK WARNING COUNT BEFORE SENDING SHOW.
+     * 
+     * @throws Exception
+     */
+    @Test
+    public void testBug101389() throws Exception {
+        Properties props = new Properties();
+        props.setProperty(PropertyKey.sslMode.getKeyName(), SslMode.DISABLED.name());
+        props.setProperty(PropertyKey.allowPublicKeyRetrieval.getKeyName(), "true");
+        props.setProperty(PropertyKey.queryInterceptors.getKeyName(), Bug101389QueryInterceptor.class.getName());
+
+        boolean useSPS = false;
+        do {
+            props.setProperty(PropertyKey.useServerPrepStmts.getKeyName(), Boolean.toString(useSPS));
+
+            Bug101389QueryInterceptor.enabled = false; // some warnings are expected here when running against old server versions
+            java.sql.Connection testConn = getConnectionWithProps(props);
+
+            Bug101389QueryInterceptor.enabled = true;
+            Statement st = testConn.createStatement();
+            st.executeQuery("SELECT 1 FROM dual;");
+            st.getWarnings();
+
+            PreparedStatement ps = testConn.prepareStatement("SELECT 1 FROM dual;");
+            ps.execute();
+            ps.getWarnings();
+
+            testConn.close();
+        } while ((useSPS = !useSPS));
+
+    }
+
+    public static class Bug101389QueryInterceptor extends BaseQueryInterceptor {
+        public static boolean enabled = false;
+
+        @Override
+        public <T extends Resultset> T preProcess(Supplier<String> sql, Query interceptedQuery) {
+            if (enabled) {
+                assertFalse(sql.get().contains("SHOW WARNINGS"), "Unexpected [SHOW WARNINGS] was issued");
+            }
+            return super.preProcess(sql, interceptedQuery);
+        }
+
+        @Override
+        public <M extends Message> M preProcess(M queryPacket) {
+            if (enabled) {
+                String sql = StringUtils.toString(queryPacket.getByteBuffer(), 1, (queryPacket.getPosition() - 1));
+                assertFalse(sql.contains("SHOW WARNINGS"), "Unexpected [SHOW WARNINGS] was issued");
+            }
+            return super.preProcess(queryPacket);
+        }
+    }
 }

src/test/java/testsuite/regression/SyntaxRegressionTest.java

@@ -1237,7 +1237,6 @@ public void testHints() throws Exception {
         }
     }
 
-    @Test
     private void testHintsSyntax(String query, boolean processesHint, boolean warningExpected) throws Exception {
         this.stmt.clearWarnings();
         this.rs = this.stmt.executeQuery(query);