Fix timestamp before epoch with micros/nanos (1.4)

This is a backport of the PR #377 to `v1.4-andium` stable branch.

This PR fixes the problem with converting `TIMESTAMP` values into
`LocalDateTime` where, when micros/nanos part was present, the
calculation may have been shifted by 1 second.

Fixes: #336

Author: staticlibs

src/main/java/org/duckdb/DuckDBTimestamp.java

@@ -40,13 +40,13 @@ private static Instant createInstant(long value, ChronoUnit unit) throws SQLExce
         case MILLIS:
             return Instant.ofEpochMilli(value);
         case MICROS: {
-            long epochSecond = value / 1_000_000;
-            int nanoAdjustment = nanosPartMicros(value);
+            long epochSecond = value / 1_000_000L;
+            long nanoAdjustment = (value % 1_000_000L) * 1000L;
             return Instant.ofEpochSecond(epochSecond, nanoAdjustment);
         }
         case NANOS: {
-            long epochSecond = value / 1_000_000_000;
-            long nanoAdjustment = nanosPartNanos(value);
+            long epochSecond = value / 1_000_000_000L;
+            long nanoAdjustment = value % 1_000_000_000L;
             return Instant.ofEpochSecond(epochSecond, nanoAdjustment);
         }
         default:
@@ -166,20 +166,4 @@ private static int nanosPartMicros(long micros) {
             return (int) ((1000_000L + (micros % 1000_000L)) * 1000);
         }
     }
-
-    private static long nanos2seconds(long nanos) {
-        if ((nanos % 1_000_000_000L) >= 0) {
-            return nanos / 1_000_000_000L;
-        } else {
-            return (nanos / 1_000_000_000L) - 1;
-        }
-    }
-
-    private static int nanosPartNanos(long nanos) {
-        if ((nanos % 1_000_000_000L) >= 0) {
-            return (int) ((nanos % 1_000_000_000L));
-        } else {
-            return (int) ((1_000_000_000L + (nanos % 1_000_000_000L)));
-        }
-    }
 }

src/test/java/org/duckdb/TestDuckDBJDBC.java

@@ -2283,7 +2283,7 @@ private static OffsetDateTime localDateTimeToOffset(LocalDateTime ldt) {
                                     localDateTimeToOffset(LocalDateTime.ofInstant(
                                         Instant.parse("+294247-01-10T04:00:54.775807Z"), ZoneId.systemDefault())),
                                     localDateTimeToOffset(LocalDateTime.ofInstant(
-                                        Instant.parse("-290308-12-21T19:59:06.224193Z"), ZoneId.systemDefault())),
+                                        Instant.parse("-290308-12-21T19:59:05.224193Z"), ZoneId.systemDefault())),
                                     null,
                                     localDateTimeToOffset(LocalDateTime.ofInstant(Instant.parse("2022-05-12T23:23:45Z"),
                                                                                   ZoneId.systemDefault()))));

src/test/java/org/duckdb/TestTimestamp.java

@@ -70,7 +70,7 @@ public static void test_timestamp_tz() throws Exception {
             OffsetDateTime odt1 = OffsetDateTime.of(2020, 10, 7, 13, 15, 7, 12345, ZoneOffset.ofHours(7));
             OffsetDateTime odt1Rounded = OffsetDateTime.of(2020, 10, 7, 13, 15, 7, 12000, ZoneOffset.ofHours(7));
             OffsetDateTime odt2 = OffsetDateTime.of(1878, 10, 2, 1, 15, 7, 12345, ZoneOffset.ofHours(-5));
-            OffsetDateTime odt2Rounded = OffsetDateTime.of(1878, 10, 2, 1, 15, 8, 13000, ZoneOffset.ofHours(-5));
+            OffsetDateTime odt2Rounded = OffsetDateTime.of(1878, 10, 2, 1, 15, 7, 13000, ZoneOffset.ofHours(-5));
             OffsetDateTime odt3 = OffsetDateTime.of(2022, 1, 1, 12, 11, 10, 0, ZoneOffset.ofHours(2));
             OffsetDateTime odt4 = OffsetDateTime.of(2022, 1, 1, 12, 11, 10, 0, ZoneOffset.ofHours(0));
             OffsetDateTime odt5 = OffsetDateTime.of(1900, 11, 27, 23, 59, 59, 0, ZoneOffset.ofHours(1));
@@ -102,7 +102,7 @@ public static void test_timestamp_tz() throws Exception {
                 // Metadata tests
                 assertEquals(Types.TIMESTAMP_WITH_TIMEZONE,
                              DuckDBResultSetMetaData.type_to_int(DuckDBColumnType.TIMESTAMP_WITH_TIME_ZONE));
-                assertTrue(OffsetDateTime.class.getName().equals(meta.getColumnClassName(2)));
+                assertEquals(OffsetDateTime.class.getName(), meta.getColumnClassName(2));
             }
         } finally {
             TimeZone.setDefault(defaultTimeZone);
@@ -296,7 +296,7 @@ public static void duckdb_timestamp_test() throws Exception {
                 ps.setTimestamp(1, Timestamp.valueOf("1905-11-02 07:59:58.12345"));
                 try (ResultSet rs6 = ps.executeQuery()) {
                     assertTrue(rs6.next());
-                    assertEquals(rs6.getTimestamp(1), Timestamp.valueOf("1905-11-02 07:59:59.12345"));
+                    assertEquals(rs6.getTimestamp(1), Timestamp.valueOf("1905-11-02 07:59:58.12345"));
                 }
             }
         }
@@ -555,4 +555,30 @@ public static void test_bug532_timestamp() throws Exception {
             }
         }
     }
+
+    public static void test_timestamp_before_epoch() throws Exception {
+        TimeZone defaultTimeZone = TimeZone.getDefault();
+        TimeZone activeTimeZone = TimeZone.getTimeZone("Europe/Sofia");
+        TimeZone.setDefault(activeTimeZone);
+        try (Connection conn = DriverManager.getConnection(JDBC_URL); Statement stmt = conn.createStatement()) {
+
+            try (ResultSet rs = stmt.executeQuery("SELECT TIMESTAMP '1969-01-01 00:00:00.123456'")) {
+                rs.next();
+                assertEquals(rs.getObject(1, LocalDateTime.class), LocalDateTime.of(1969, 1, 1, 0, 0, 0, 123456000));
+            }
+
+            try (ResultSet rs = stmt.executeQuery("SELECT TIMESTAMP_NS '1969-01-01 00:00:00.123456789'")) {
+                rs.next();
+                assertEquals(rs.getObject(1, LocalDateTime.class), LocalDateTime.of(1969, 1, 1, 0, 0, 0, 123456789));
+            }
+
+            try (ResultSet rs = stmt.executeQuery("SELECT TIMESTAMP WITH TIME ZONE '1969-01-01 00:00:00.123456Z'")) {
+                rs.next();
+                assertEquals(rs.getObject(1, LocalDateTime.class), LocalDateTime.of(1969, 1, 1, 2, 0, 0, 123456000));
+            }
+
+        } finally {
+            TimeZone.setDefault(defaultTimeZone);
+        }
+    }
 }