Merge 84919 - 2011-04-26 Ryosuke Niwa <rniwa@webkit.org>

Merge 84919 - 2011-04-26  Ryosuke Niwa  <rniwa@webkit.org>;

        Reviewed by Dan Bernstein.

        [RTL] Arabic/AB - after typing a date, cursors doesn't go back
        https://bugs.webkit.org/show_bug.cgi?id=49111

        Added a test to move left and right within Arabic numerals and Arabic letters.

        We still fail to set the position offset properly when we moving to the left from before B
        to before A in "ABC123" (logical order) in a LTR block where ABC and 123 are Arabic letters
        and numerals respectively. This bug is to be fixed in the followup bugs.

        * editing/selection/move-left-right-expected.txt:
        * editing/selection/move-left-right.html:
2011-04-26  Ryosuke Niwa  <rniwa@webkit.org>;

        Reviewed by Dan Bernstein.

        [RTL] Arabic/AB - after typing a date, cursors doesn't go back
        https://bugs.webkit.org/show_bug.cgi?id=49111

        Even when the offset corresponds to a position visually left of the box
        and there aren't any inline boxes on the left, the previous/next position
        may still correspond to some position in the same line.

        The bug was caused by our ignoring such cases. Fixed the bug by comparing
        previous/next position's inline box to the current box. If they match,
        then we stay on the same position because moving to the left visually at
        the left edge should not result in a position on the same line.

        Also fixed a bug that WebKit uses offsets that are not extrema when moved to
        the left edge or to the right edge, and a bug that WebKit could not move to
        the left from 12^3 CBA abc to 123 C^BA abc (there is no offset between 3 and C).

        Test cases are added to editing/selection/move-left-right.html

        * editing/VisiblePosition.cpp:
        (WebCore::VisiblePosition::leftVisuallyDistinctCandidate):
        (WebCore::VisiblePosition::rightVisuallyDistinctCandidate):
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=85552