diff --git a/pgjdbc/src/main/java/org/postgresql/core/PGStream.java b/pgjdbc/src/main/java/org/postgresql/core/PGStream.java
index 3f41803a44..7ed6fc3e55 100644
--- a/pgjdbc/src/main/java/org/postgresql/core/PGStream.java
+++ b/pgjdbc/src/main/java/org/postgresql/core/PGStream.java
@@ -423,8 +423,7 @@ public String receiveString() throws IOException {
    * @throws IOException if a data I/O error occurs
    */
   public byte[][] receiveTupleV3() throws IOException, OutOfMemoryError {
-    // TODO: use msgSize
-    int msgSize = receiveInteger4();
+    receiveInteger4(); // MESSAGE SIZE
     int nf = receiveInteger2();
     byte[][] answer = new byte[nf][];
 
diff --git a/pgjdbc/src/main/java/org/postgresql/core/v3/QueryExecutorImpl.java b/pgjdbc/src/main/java/org/postgresql/core/v3/QueryExecutorImpl.java
index 8bfd65eeb5..f43bb78b56 100644
--- a/pgjdbc/src/main/java/org/postgresql/core/v3/QueryExecutorImpl.java
+++ b/pgjdbc/src/main/java/org/postgresql/core/v3/QueryExecutorImpl.java
@@ -2413,7 +2413,7 @@ public void handleCommandStatus(String status, int updateCount, long insertOID)
    * Receive the field descriptions from the back end.
    */
   private Field[] receiveFields() throws IOException {
-    int msgSize = pgStream.receiveInteger4();
+    pgStream.receiveInteger4(); // MESSAGE SIZE
     int size = pgStream.receiveInteger2();
     Field[] fields = new Field[size];
 
@@ -2440,7 +2440,7 @@ private Field[] receiveFields() throws IOException {
   }
 
   private void receiveAsyncNotify() throws IOException {
-    int msglen = pgStream.receiveInteger4();
+    pgStream.receiveInteger4(); // MESSAGE SIZE
     int pid = pgStream.receiveInteger4();
     String msg = pgStream.receiveString();
     String param = pgStream.receiveString();
@@ -2611,7 +2611,7 @@ public void readStartupMessages() throws IOException, SQLException {
 
   public void receiveParameterStatus() throws IOException, SQLException {
     // ParameterStatus
-    int len = pgStream.receiveInteger4();
+    pgStream.receiveInteger4(); // MESSAGE SIZE
     String name = pgStream.receiveString();
     String value = pgStream.receiveString();
 
diff --git a/pgjdbc/src/main/java/org/postgresql/jdbc/EscapedFunctions2.java b/pgjdbc/src/main/java/org/postgresql/jdbc/EscapedFunctions2.java
index 449aef03ba..65205f47e5 100644
--- a/pgjdbc/src/main/java/org/postgresql/jdbc/EscapedFunctions2.java
+++ b/pgjdbc/src/main/java/org/postgresql/jdbc/EscapedFunctions2.java
@@ -60,8 +60,9 @@ public static Method getFunction(String functionName) {
     if (method != null) {
       return method;
     }
+    //FIXME: this probably should not use the US locale
     String nameLower = functionName.toLowerCase(Locale.US);
-    if (nameLower == functionName) {
+    if (nameLower.equals(functionName)) {
       // Input name was in lower case, the function is not there
       return null;
     }
diff --git a/pgjdbc/src/main/java/org/postgresql/jdbc/PgArray.java b/pgjdbc/src/main/java/org/postgresql/jdbc/PgArray.java
index d7668a0349..190d96ad42 100644
--- a/pgjdbc/src/main/java/org/postgresql/jdbc/PgArray.java
+++ b/pgjdbc/src/main/java/org/postgresql/jdbc/PgArray.java
@@ -906,7 +906,8 @@ public String toString() {
 
         final PrimitiveArraySupport arraySupport = PrimitiveArraySupport.getArraySupport(array);
         if (arraySupport != null) {
-          fieldString = arraySupport.toArrayString(connection.getTypeInfo().getArrayDelimiter(oid), array);
+          fieldString =
+            arraySupport.toArrayString(connection.getTypeInfo().getArrayDelimiter(oid), array);
         } else {
           java.sql.Array tmpArray = connection.createArrayOf(getBaseTypeName(), (Object[]) array);
           fieldString = tmpArray.toString();
@@ -914,6 +915,9 @@ public String toString() {
       } catch (SQLException e) {
         fieldString = "NULL"; // punt
       }
+    } else {
+      // avoid returning null
+      fieldString = "NULL";
     }
     return fieldString;
   }
diff --git a/pgjdbc/src/main/java/org/postgresql/jdbc/TimestampUtils.java b/pgjdbc/src/main/java/org/postgresql/jdbc/TimestampUtils.java
index 30e9f2a06a..dc5240fde3 100644
--- a/pgjdbc/src/main/java/org/postgresql/jdbc/TimestampUtils.java
+++ b/pgjdbc/src/main/java/org/postgresql/jdbc/TimestampUtils.java
@@ -511,7 +511,7 @@ public synchronized Time toTime(Calendar cal, String s) throws SQLException {
     }
 
     // 2) Truncate date part so in given time zone the date would be formatted as 01/01/1970
-    return convertToTime(timeMillis, useCal == null ? null : useCal.getTimeZone());
+    return convertToTime(timeMillis, useCal.getTimeZone());
   }
 
   public synchronized Date toDate(Calendar cal, String s) throws SQLException {
@@ -1362,7 +1362,7 @@ private static long toPgSecs(long secs) {
         int years = (int) ((secs + 15773356800L) / -3155823050L);
         years++;
         years -= years / 4;
-        secs += years * 86400;
+        secs += years * 86400L;
       }
     }
 
diff --git a/pgjdbc/src/main/java/org/postgresql/largeobject/LargeObjectManager.java b/pgjdbc/src/main/java/org/postgresql/largeobject/LargeObjectManager.java
index 95b94714e5..bb7b156ce3 100644
--- a/pgjdbc/src/main/java/org/postgresql/largeobject/LargeObjectManager.java
+++ b/pgjdbc/src/main/java/org/postgresql/largeobject/LargeObjectManager.java
@@ -132,11 +132,6 @@ public LargeObjectManager(BaseConnection conn) throws SQLException {
     Statement stmt = conn.createStatement();
     ResultSet res = stmt.executeQuery(sql);
 
-    if (res == null) { // NOSONAR
-      throw new PSQLException(GT.tr("Failed to initialize LargeObject API"),
-          PSQLState.SYSTEM_ERROR);
-    }
-
     fp.addFunctions(res);
     res.close();
     stmt.close();
diff --git a/pgjdbc/src/main/java/org/postgresql/ssl/SingleCertValidatingFactory.java b/pgjdbc/src/main/java/org/postgresql/ssl/SingleCertValidatingFactory.java
index ff45925c2d..633aa6802a 100644
--- a/pgjdbc/src/main/java/org/postgresql/ssl/SingleCertValidatingFactory.java
+++ b/pgjdbc/src/main/java/org/postgresql/ssl/SingleCertValidatingFactory.java
@@ -142,7 +142,7 @@ public SingleCertValidatingFactory(String sslFactoryArg) throws GeneralSecurityE
     }
   }
 
-  public class SingleCertTrustManager implements X509TrustManager {
+  public static class SingleCertTrustManager implements X509TrustManager {
     X509Certificate cert;
     X509TrustManager trustManager;