A DESCRIPTION OF THE PROBLEM :
toLocalDate() produces a result that is not the inverse of valueOf(LocalDate) for dates before year 1 A.D. In fact years in the B.C. eara are switched to the A.D. eara. So in the executable test case given below, the sqld1 is set to year 2 B.C., but when converted to LocalDate and back again sqld2 becomes year 2 A.D. (Converting year -1 to 2 B.C. is all right considering the Gregorian calendar in java.sql.Date does not have a year 0)

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
See source code for an executable test case.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
'0002-01-01 B.C.'.equals('0002-01-01 B.C.'): true, or similar
'-0001-01-01'.equals('-0001-01-01'): true

ACTUAL -
'0002-01-01'.equals('0002-01-01'): false
'-0001-01-01'.equals('0002-01-01'): false


---------- BEGIN SOURCE ----------
LocalDate ld = LocalDate.of(-1, Month.JANUARY, 1);
java.sql.Date sqld1 = java.sql.Date.valueOf(ld);
LocalDate ld1 = sqld1.toLocalDate();
java.sql.Date sqld2 = java.sql.Date.valueOf(ld1);
System.out.printf("'%s'.equals('%s'): %b", sqld2, sqld1, sqld2.equals(sqld1));
System.out.println();
System.out.printf("'%s'.equals('%s'): %b", ld, ld1, ld.equals(ld1));

---------- END SOURCE ----------

FREQUENCY : always