Fix for Bulkcopy multi byte chars in char/varchar columns

src/main/java/com/microsoft/sqlserver/jdbc/IOBuffer.java

@@ -4018,8 +4018,7 @@ void writeStream(InputStream inputStream, long advertisedLength,
      * efficiency. As this method will only be used in bulk copy, it needs to be efficient. Note: Any changes in
      * algorithm/logic should propagate to both writeReader() and writeNonUnicodeReader().
      */
-    void writeNonUnicodeReader(Reader reader, long advertisedLength, boolean isDestBinary,
-            Charset charSet) throws SQLServerException {
+    void writeNonUnicodeReader(Reader reader, long advertisedLength, boolean isDestBinary) throws SQLServerException {
         assert DataTypes.UNKNOWN_STREAM_LENGTH == advertisedLength || advertisedLength >= 0;
 
         long actualLength = 0;
@@ -4057,6 +4056,9 @@ void writeNonUnicodeReader(Reader reader, long advertisedLength, boolean isDestB
                 // in this last round the only thing that is written is an int value of 0, which is the PLP Terminator
                 // token(0x00000000).
 
+                // collation from database is the collation used
+                Charset charSet = con.getDatabaseCollation().getCharset();
+
                 if (null == charSet) {
                     writeInt(charsToWrite);
 
@@ -4066,20 +4068,16 @@ void writeNonUnicodeReader(Reader reader, long advertisedLength, boolean isDestB
 
                     writeBytes(streamByteBuffer, 0, charsToWrite);
                 } else {
-                    // encoding as per collation
-                    int bytesPerChar = (int) (1 / (Charset.forName(charSet.name()).newDecoder().averageCharsPerByte()));
-                    writeInt(charsToWrite * bytesPerChar);
-
+                    bytesToWrite = 0;
+                    byte[] charBytes;
                     for (int charsCopied = 0; charsCopied < charsToWrite; ++charsCopied) {
-                        streamByteBuffer[bytesPerChar * charsCopied] = new String(streamCharBuffer[charsCopied] + "")
-                                .getBytes(charSet)[0];
-                        if (bytesPerChar > 1) {
-                            streamByteBuffer[bytesPerChar * charsCopied
-                                    + 1] = new String(streamCharBuffer[charsCopied] + "").getBytes(charSet)[1];
-                        }
+                        charBytes = new String(streamCharBuffer[charsCopied] + "").getBytes(charSet);
+                        System.arraycopy(charBytes, 0, streamByteBuffer, bytesToWrite, charBytes.length);
+                        bytesToWrite += charBytes.length;
                     }
 
-                    writeBytes(streamByteBuffer, 0, bytesPerChar * charsToWrite);
+                    writeInt(bytesToWrite);
+                    writeBytes(streamByteBuffer, 0, bytesToWrite);
                 }
             } else {
                 bytesToWrite = charsToWrite;
@@ -4994,7 +4992,7 @@ private void writeInternalTVPRowValues(JDBCType jdbcType, String currentColumnSt
                         // Null header for v*max types is 0xFFFFFFFFFFFFFFFF.
                         writeLong(0xFFFFFFFFFFFFFFFFL);
                     } else if (isSqlVariant) {
-                        // for now we send as bigger type, but is sendStringParameterAsUnicoe is set to false we can't
+                        // for now we send as bigger type, but is sendStringParameterAsUnicode is set to false we can't
                         // send nvarchar
                         // since we are writing as nvarchar we need to write as tdstype.bigvarchar value because if we
                         // want to supprot varchar(8000) it becomes as nvarchar, 8000*2 therefore we should send as

src/main/java/com/microsoft/sqlserver/jdbc/SQLServerBulkCopy.java

@@ -2270,16 +2270,15 @@ else if (null != sourceCryptoMeta) {
                                 } else {
                                     if ((SSType.BINARY == destSSType) || (SSType.VARBINARY == destSSType)
                                             || (SSType.VARBINARYMAX == destSSType) || (SSType.IMAGE == destSSType)) {
-                                        tdsWriter.writeNonUnicodeReader(reader, DataTypes.UNKNOWN_STREAM_LENGTH, true,
-                                                null);
+                                        tdsWriter.writeNonUnicodeReader(reader, DataTypes.UNKNOWN_STREAM_LENGTH, true);
                                     } else {
                                         SQLCollation destCollation = destColumnMetadata.get(destColOrdinal).collation;
                                         if (null != destCollation) {
                                             tdsWriter.writeNonUnicodeReader(reader, DataTypes.UNKNOWN_STREAM_LENGTH,
-                                                    false, destCollation.getCharset());
+                                                    false);
                                         } else {
                                             tdsWriter.writeNonUnicodeReader(reader, DataTypes.UNKNOWN_STREAM_LENGTH,
-                                                    false, null);
+                                                    false);
                                         }
                                     }
                                 }

src/test/java/com/microsoft/sqlserver/jdbc/bulkCopy/BulkCopyColumnMappingTest.java

@@ -551,7 +551,7 @@ private void validateMapping(String sourceType, String destType,
                 sourceStmt.executeUpdate("CREATE TABLE " + sourceTable + " (col " + sourceType + ");");
                 sourceStmt.executeUpdate("INSERT INTO " + sourceTable + " VALUES('" + data + "');");
 
-                destStmt.executeUpdate("CREATE TABLE " + destTable + " (col NCHAR(5));");
+                destStmt.executeUpdate("CREATE TABLE " + destTable + " (col CHAR(10));");
                 ResultSet sourceRs = sourceStmt.executeQuery("SELECT * FROM " + sourceTable);
                 bulkCopy.writeToServer(sourceRs);