which we weren't treating right.
* $limit in wfDebugBacktrace() is the number of returned frames,
we thus need to take into account the wfDebugBacktrace() frame, which
is sliced from debug_backtrace().
* wfGetCaller() needs to add a level for itself.
* MWDebug::warning() was logging itself as the warning issuer,
which is useless (the call a few lines before was right, though)
MWDebugTest.php changed accordingly.
* Removed double call to wfGetCaller( $callerOffset + 1 )
* Documented the meaning of wfGetCaller() parameter
* Added unit test
Change-Id: Ief50f4c810bad8b03bb2bf9dc6d945d9acb29851
Some other test could have added their own logs, for example
deprecated notice. In that case, the first test will fail because
the log array already has some content :-b
The first ones were failing because the test suite ran on gallium without
MWDebug being initialized. This is now the case since r109033.
The second part was failling because PHPUnit on gallium does not have
the assertCount() method. Use a assertEquals() / count() workaround instead.
Tests added by 108873
Reverts r108877
