On 15 June 2017 at 10:12, Eric Engestrom <eric.engest...@imgtec.com> wrote: > On Thursday, 2017-06-15 09:56:55 +0100, Emil Velikov wrote: >> Hi Brian, >> >> On 15 June 2017 at 04:46, Brian Paul <bri...@vmware.com> wrote: >> > The SCons build has been using 10 digits of the git hash id for the >> > MESA_GIT_SHA1 string in git_sha1.h for about a year now. I bumped it >> > up after running into a case where a 7-digit hash ID was ambiguous. >> > >> > This patch makes the same change for the autotools build. >> > >> > The command "git log | grep "^commit" | cut -b 8-14 | sort | uniq -d" >> > shows there are currently 17 cases where 7 digits of hash id are >> > ambiguous on master (probably quite a few more if we'd consider other >> > branches). >> > >> > Instead of using "git log -n 1 --oneline" use >> > "git rev-parse --short=10 HEAD" to get the HEAD hash id. >> >> The current command produces 11 digit SHA > > That would depend on your git version (it used to be 7 until early 2.x > and is 10 on my 2.13.1), and your core.abbrev config :) > Hmm that may explain some of it - using 2.13.0 here. Local/global/system core.abbrev on the other hand is empty.
>> and size will grow automatically as needed. > > Ack, but only after the collision happens, I think the point is to be > big enough that the hash stored will be unique compared to (reasonably) > all the future versions. Being explicit about the min length does that. > Having it future proof sounds reasonable - thanks did not think of that. Not sure about the growth algo. See the following: $ for i in `seq 14 20`; do \ echo -n "SHA digits $[$i-8+1] -- conflicts "; \ git log | grep "^commit" | cut -b 8-$i | sort | uniq -d | wc -l; \ done SHA digits 7 -- conflicts 17 SHA digits 8 -- conflicts 1 SHA digits 9 -- conflicts 0 SHA digits 10 -- conflicts 0 SHA digits 11 -- conflicts 0 SHA digits 12 -- conflicts 0 SHA digits 13 -- conflicts 0 $ git log -n 1 --oneline 18d4a6f964c (HEAD -> master) i965: gen4_blorp_exec.h to the sources list -Emil _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
