Fix negative timezone offset parsing.

We now correctly decode the localMinutesOffset by parsing the number as small int instead of unsigned short. Also, encode the offset correctly as smallint.

[resolves #208]

Signed-off-by: Mark Paluch <mpaluch@vmware.com>

Author: mp911de

src/main/java/io/r2dbc/mssql/codec/OffsetDateTimeCodec.java

@@ -98,7 +98,7 @@ OffsetDateTime doDecode(ByteBuf buffer, Length length, TypeInformation type, Cla
         LocalTime localTime = LocalTimeCodec.INSTANCE.doDecode(buffer, length, type, LocalTime.class);
         LocalDate localDate = LocalDateCodec.INSTANCE.doDecode(buffer, length, type, LocalDate.class);
 
-        int localMinutesOffset = Decode.uShort(buffer);
+        int localMinutesOffset = Decode.smallInt(buffer);
         ZoneOffset offset = ZoneOffset.ofTotalSeconds(localMinutesOffset * 60);
 
         return OffsetDateTime.of(localTime.atDate(localDate), offset).plusMinutes(localMinutesOffset);
@@ -111,7 +111,7 @@ static void doEncode(ByteBuf buffer, OffsetDateTime value) {
 
         int localMinutesOffset = value.getOffset().getTotalSeconds() / 60;
 
-        Encode.uShort(buffer, localMinutesOffset);
+        Encode.smallInt(buffer, localMinutesOffset);
     }
 
 }

src/main/java/io/r2dbc/mssql/message/tds/Encode.java

@@ -151,6 +151,16 @@ public static void smallInt(ByteBuf buffer, short value) {
         buffer.writeShortLE(value);
     }
 
+    /**
+     * Encode short number. SQL server type {@code SMALLINT}.
+     *
+     * @param buffer the data buffer.
+     * @param value  the value to encode.
+     */
+    public static void smallInt(ByteBuf buffer, int value) {
+        buffer.writeShortLE(value);
+    }
+
     /**
      * Encode integer number. SQL server type {@code INT}.
      *

src/test/java/io/r2dbc/mssql/CodecIntegrationTests.java

@@ -143,6 +143,7 @@ void shouldEncodeDateTime2() {
     @Test
     void shouldEncodeZonedDateTimeAsDatetimeoffset() {
         testType(connection, "DATETIMEOFFSET", ZonedDateTime.parse("2018-08-27T17:41:14.890+00:45"), ZonedDateTime.class, OffsetDateTime.parse("2018-08-27T17:41:14.890+00:45"));
+        testType(connection, "DATETIMEOFFSET", ZonedDateTime.parse("2018-08-27T17:41:14.890-01:45"), ZonedDateTime.class, OffsetDateTime.parse("2018-08-27T17:41:14.890-01:45"));
     }
 
     @Test

src/test/java/io/r2dbc/mssql/codec/OffsetDateTimeCodecUnitTests.java

@@ -49,6 +49,17 @@ void shouldEncodeDatetimeoffset() {
         assertThat(encoded.getFormalType()).isEqualTo("datetimeoffset");
     }
 
+    @Test
+    void shouldEncodeDatetimeOffsetNegativeTz() {
+
+        OffsetDateTime value = OffsetDateTime.parse("2018-08-27T17:41:14.890-00:45");
+
+        Encoded encoded = OffsetDateTimeCodec.INSTANCE.encode(TestByteBufAllocator.TEST, RpcParameterContext.out(), value);
+
+        EncodedAssert.assertThat(encoded).isEqualToHex("07 0a a0 74 84 8a 9a a4 3e 0b d3 ff");
+        assertThat(encoded.getFormalType()).isEqualTo("datetimeoffset");
+    }
+
     @Test
     void shouldEncodeNull() {
 
@@ -67,4 +78,15 @@ void shouldDecodeDateTimeOffset() {
 
         assertThat(decoded).isEqualTo("2018-08-27T17:41:14.890+00:45");
     }
+
+    @Test
+    void shouldDecodeDateTimeOffsetNegativeTz() {
+
+        ByteBuf buffer = HexUtils.decodeToByteBuf("0a a0 74 84 8a 9a a4 3e 0b d3 ff");
+
+        OffsetDateTime decoded = OffsetDateTimeCodec.INSTANCE.decode(buffer, ColumnUtil.createColumn(DATETIMEOFFSET), OffsetDateTime.class);
+
+        assertThat(decoded).isEqualTo("2018-08-27T17:41:14.890-00:45");
+    }
+
 }