From: Phil Pennock <pdp@exim.org>
Date: Wed, 18 Jan 2017 16:39:24 +0000 (-0500)
Subject: Recording merge technique in git history
X-Git-Tag: exim-4_89_RC1~40
X-Git-Url: https://git.exim.org/exim.git/commitdiff_plain/585546e0a422f5fe172258c9054a7840697d9ec0

Recording merge technique in git history

This is an empty commit which exists for this commit message,
documenting how I handled GitHub PR 52, which was 228 separate commits,
each fixing the spelling of one word.  The submitter's approach made it
easy to consider and approve/reject each independently, so was valuable,
but I didn't want so many commits in our history.

A few aspects of the shell commands rely upon Zsh: `read -q` for
getting a single Y/N response; `$IFS` containing ASCII NUL (and
builtins handling NUL inside strings) for parsing `.git/MERGE_RR`;
anonymous function calls so that I could abort cleanly if I wanted to.

    git log --pretty=tformat:%h master..github/pr/52  > ../1.consider
    touch ../2.keep
    for F in $(<../1.consider); do git show $F | cat -v; read -q "keep?Keep $F ? " && echo $F >> ../2.keep; echo; echo =============================; done

That let me iterate through each, selecting 214/228 commits to apply in
one pass.  Two PR commits were held for a separate commit, because they
fixed behavioural bugs.  So 216/228 were accepted.  A couple warranted
minor post-fixing as part of the first PR.

    for F in $(<../2.keep ) ; do (){ git cherry-pick -n $F && continue; for junk fn in $(<.git/MERGE_RR); do [[ -n $fn ]] || break; if vi $fn; then git add $fn; else return 1; fi; done } || break; done
    vi src/src/filter.c && git add src/src/filter.c
    vi src/src/dns.c && git add src/src/dns.c
    GIT_AUTHOR_NAME='Josh Soref' GIT_AUTHOR_EMAIL='jsoref@users.noreply.github.com' git commit

and similarly for the second commit.

One more commit from the PR requires chasing with a contributor whose
name is natively in a non-Roman alphabet and who appears to have changed
the Romanisation, to check how they'd like it handled.  I will chase
under separate cover.
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