Such files do not exist (as per QFileInfo::exists), but on some
platforms that rely on realpath(), QFileInfo::canonicalFilePath did
not return the empty string.
Use the same logic on macOS as we already did on Android, and include
a test case. Remove the unnecessary dynamic memory allocation and
use a stack-allocated array instead, unless we use modern POSIX in
which case realpath() will alloc the memory for the result for us.
Change-Id: Ide987c68ebf00cbb7b1a66c2e9245a12c7807128
Fixes: QTBUG-44242
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
bd55a9d912