a11y tests: Don't assume that child on top has higher child index HEADmaster

An accessible can have multiple children at the same point. As the
XAccessibleComponent::getAccessibleAtPoint doc says:

@return
If there is one child which is rendered so that its bounding box
contains the test point then a reference to that object is
returned.  If there is more than one child which satisfies that
condition then a reference to that one is returned that is
painted on top of the others.  If there is no child which is
rendered at the test point an empty reference is returned.

So far, XAccessibleComponentTester::testAccessibleAtPoint was making
the assumption that if multiple children are at the same point, the
one on top has the higher child index. Otherwise, the test would fail.

The reason for that assumption is unclear. Replace that by checking
whether the accessible returned by XAccessibleComponent::getAccessibleAtPoint
is a direct child (by checking its parent) and actually contains the
point instead.

Without this, the test was seen failing in a WIP branch that converts
the AccessibleDropDownListBox JUnit test to a cppunit test.
Related failure output:

Found 2 children
* Found child: (0x562c20b3b7b8) role=TEXT name="" description=""
states: ENABLED | SENSITIVE
component: 0x562c20b3b770
bounds: X: 0, Y: 0, Width: 100, Height: 21
bounds: 100x21+0+0
finding the point which lies on the component
Child found at point +0+0
* Found child: (0x562c20b30028) role=LIST name="" description=""
states: ENABLED | FOCUSABLE | MANAGES_DESCENDANTS | SENSITIVE
component: 0x562c20b30010
bounds: X: 0, Y: 20, Width: 100, Height: 88
bounds: 100x88+0+20
finding the point which lies on the component
Child found at point +0+20
The child found ((0x562c20b3b7b8) role=TEXT name="" description="") is not the expected one ((0x562c20b30028) role=LIST name="" description="")
/home/michi/development/git/libreoffice/test/source/a11y/XAccessibleComponentTester.cxx:204:AccessibleDropDownListBox::TestBody
equality assertion failed
- Expected: (0x562c20b30028) role=LIST name="" description=""
- Actual  : (0x562c20b3b7b8) role=TEXT name="" description=""
- The child found is NOT the expected one

Change-Id: I8bc01c333ff0b3b9e90948bfd21b5abb86989687
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/182968
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
Tested-by: Jenkins

0 files changed, 0 insertions, 0 deletions