Code review comment for lp:~gordallott/unity/fix-937421

Without knowing precicely what the bad pixbuf is, a test is meaningless, it may or may not be testing what you thought it was and it certainly does not verrify that the bug itself is fixed

What we need is an application guarunteed to cause the bug, so we can look at the real reason as to why a bad pixbuf is generated in the first place and potentially build ap tests using that application.

I really can't think of a way of testing this change that doesn't basically just boil down to writing EXPECT_EQ(GDK_IS_PIXBUF(NULL), FALSE);