tdf#157696 a11y: Escape commas in IAccessible2 color text attribute

The IAccessible2 text attribute specification [1] says:

> These characters need to be escaped with a backslash:
> backslash, colon, comma, equals, and semicolon.

So adhere to this. Otherwise, the NVDA screen reader
is unable to announce the text foreground or background
color properly in local WIP branches of both LO and NVDA
to use IAccessible2 text attributes on Windows as well.

With this change in place, the backslashes are also
contained in the corresponding AT-SPI attributes when using
the qt6 VCL plugin on Linux.
That seems undesirable there (s. e.g. the ATK text
attribute spec [2] and how the Gtk variant of LO
and also the gtk4-demo "Hypertext" example" expose it),
but I think this should rather be handled in Qt's
AT-SPI adaptor's mapping of the IAccessible2 attributes
to the AT-SPI ones.
Pending Qt Gerrit change implementing this: [3]

(At least Orca still announces the colors just fine
with the additional backslash in place, so having
an extra platform-specific handling here doesn't
seem to be urgent for now.)

[1] https://wiki.linuxfoundation.org/accessibility/iaccessible2/textattributes#formatting
[2] https://gnome.pages.gitlab.gnome.org/atk/AtkText.html#AtkTextAttribute
[3] https://codereview.qt-project.org/c/qt/qtbase/+/511132

Change-Id: I51780f44930089249a769522d7130e97ac5446b7
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/157845
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

0 files changed, 0 insertions, 0 deletions