I performed some reverse commit bisect and thus tested some 4.X kernels. Here's the result:
1) The bug is present in all 4.4.X kernels until kernel "4.5.7-yakkety" (build 4.5.7-040507-generic), which's the last one carrying the bad commit.
Starting on kernel "4.6-rc1" (build 4.6.0-040600rc1-generic), the bug is gone.
Hence, a "good commit" removed the bad commit on 4.6-rc1.
I performed some reverse commit bisect and thus tested some 4.X kernels. Here's the result:
1) The bug is present in all 4.4.X kernels until kernel "4.5.7-yakkety" (build 4.5.7-040507- generic) , which's the last one carrying the bad commit.
Starting on kernel "4.6-rc1" (build 4.6.0-040600rc1 -generic) , the bug is gone.
Hence, a "good commit" removed the bad commit on 4.6-rc1.