yearMonthDuration arithmetic bug

[Paul J. Lucas]

Given:

let $t := xs:date("1900-01-01")
return
    for $i in 1 to 75
    return $t + xs:yearMonthDuration('P1Y') * $i

one gets:

1901-01-01 1902-01-01 1903-01-01 1904-01-01 1905-01-01 1906-01-01 1907-01-01 1908-01-01 1909-01-01 1910-01-01 1911-01-01 1912-01-01 1913-01-01 1914-01-01 1915-01-01 1916-01-01 1917-01-01 1918-01-01 1919-01-01 1920-01-01 1921-01-01 1922-01-01 1923-01-01 1924-01-01 1925-01-01 1926-01-01 1927-01-01 1928-01-01 1929-01-01 1930-01-01 1931-01-01 1932-01-01 1933-01-01 1934-01-01 1935-01-01 1936-01-01 1937-01-01 1938-01-01 1939-01-01 1940-01-01 1941-01-01 1942-01-01 1943-01-01 1944-01-01 1945-01-01 1946-01-01 1947-01-01 1948-01-01 1949-01-01 1950-01-01 1951-01-01 1952-01-01 1953-01-01 1954-01-01 1955-01-01 1956-01-01 1957-01-01 1958-01-01 1959-01-01 1960-01-01 1961-01-01 1962-01-01 1963-01-01 1964-01-01 1965-01-01 1966-01-01 1967-01-01 1968-01-01 1969-01-01 1969-02-01 1969-02-01 1969-02-01 1969-02-01 1969-02-01 1969-02-01

Notice that it gets stuck on the year 1969 at the end (and that the month changes to 02).

Initial assignment to Matthias. Nicolae has the FOTS duration bugs assigned to him. Perhaps he should have this one assign too? Reassign as appropriate.

[Matthias Brantner (matthias-brantner)]

Assigning to Nicolae because it might be related to https://bugs.launchpad.net/zorba/+bug/1123836.

[Paul J. Lucas (paul-lucas)]

This may also affect FOTS tests format-date-005 and format-date-006.