I did a reverse bisect and found this to be the first 'bad' commit:
commit 45a78b88dba1db5758f68d0d3229d3cb42da6050
Author: Theodore Ts'o <email address hidden>
Date: Sun Apr 27 15:52:48 2014 -0400
resize2fs: refine minimum required blocks for flex_bg file systems
I did a reverse bisect and found this to be the first 'bad' commit: 758f68d0d3229d3 cb42da6050
commit 45a78b88dba1db5
Author: Theodore Ts'o <email address hidden>
Date: Sun Apr 27 15:52:48 2014 -0400
resize2fs: refine minimum required blocks for flex_bg file systems