Stefan Beller <sbeller@xxxxxxxxxx> writes: > So I tried finding out more about this hack, > and found the patch that introduced the common tail trimming at > https://public-inbox.org/git/7vmysez0oa.fsf@xxxxxxxxxxxxxxxxxxxxxxxxxx/ > 913b45f51b (xdi_diff: trim common trailing lines, 2007-12-13) A relevant one that makes me hesitate to take this kind of change is this: https://public-inbox.org/git/alpine.LFD.0.9999.0712202009290.21557@xxxxxxxxxxxxxxxxxxxxxxxxxx/#t that resulted in this change: commit d2f82950a9226ae1102a7a97f03440a4bf8c6c09 Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Date: Thu Dec 20 20:22:46 2007 -0800 Re(-re)*fix trim_common_tail() The tar-ball and the git archive itself is fine, but yes, the diff from 2.6.23 to 2.6.24-rc6 is bad. It's the "trim_common_tail()" optimization that has caused way too much pain. Very interesting breakage. The patch was actually "correct" in a (rather limited) technical sense, but the context at the end was missing because while the trim_common_tail() code made sure to keep enough common context to allow a valid diff to be generated, the diff machinery itself could decide that it could generate the diff differently than the "obvious" solution. Thee sad fact is that the git optimization (which is very important for "git blame", which needs no context), is only really valid for that one case where we really don't need any context.
