hook: add sample template for push-to-checkout
The template is a more-or-less exact translation to shell of the C code for the default behaviour for git's push-to-checkout hook defined in the push_to_deploy() function in builtin/receive-pack.c, to serve as a convenient starting point for modification. It also contains relevant text extracted from the git-config(1) and githooks(5) man pages. Signed-off-by: Adam Spiers <git@adamspiers.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Adam Spiers committed
Oct 15, 2020 at 23:54 UTC
e632c464d5dbbda72ae370ff6e9cbe31c01b0bb0
1 file changed
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templates/hooks--push-to-checkout.sample
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+#!/bin/sh
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+
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+# An example hook script to update a checked-out tree on a git push.
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+#
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+# This hook is invoked by git-receive-pack(1) when it reacts to git
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+# push and updates reference(s) in its repository, and when the push
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+# tries to update the branch that is currently checked out and the
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+# receive.denyCurrentBranch configuration variable is set to
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+# updateInstead.
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+#
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+# By default, such a push is refused if the working tree and the index
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+# of the remote repository has any difference from the currently
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+# checked out commit; when both the working tree and the index match
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+# the current commit, they are updated to match the newly pushed tip
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+# of the branch. This hook is to be used to override the default
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+# behaviour; however the code below reimplements the default behaviour
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+# as a starting point for convenient modification.
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+#
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+# The hook receives the commit with which the tip of the current
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+# branch is going to be updated:
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+commit=$1
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+
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+# It can exit with a non-zero status to refuse the push (when it does
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+# so, it must not modify the index or the working tree).
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+die () {
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+ echo >&2 "$*"
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+ exit 1
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+}
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+
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+# Or it can make any necessary changes to the working tree and to the
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+# index to bring them to the desired state when the tip of the current
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+# branch is updated to the new commit, and exit with a zero status.
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+#
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+# For example, the hook can simply run git read-tree -u -m HEAD "$1"
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+# in order to emulate git fetch that is run in the reverse direction
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+# with git push, as the two-tree form of git read-tree -u -m is
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+# essentially the same as git switch or git checkout that switches
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+# branches while keeping the local changes in the working tree that do
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+# not interfere with the difference between the branches.
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+
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+# The below is a more-or-less exact translation to shell of the C code
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+# for the default behaviour for git's push-to-checkout hook defined in
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+# the push_to_deploy() function in builtin/receive-pack.c.
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+#
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+# Note that the hook will be executed from the repository directory,
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+# not from the working tree, so if you want to perform operations on
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+# the working tree, you will have to adapt your code accordingly, e.g.
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+# by adding "cd .." or using relative paths.
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+
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+if ! git update-index -q --ignore-submodules --refresh
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+then
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+ die "Up-to-date check failed"
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+fi
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+
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+if ! git diff-files --quiet --ignore-submodules --
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+then
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+ die "Working directory has unstaged changes"
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+fi
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+
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+# This is a rough translation of:
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+#
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+# head_has_history() ? "HEAD" : EMPTY_TREE_SHA1_HEX
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+if git cat-file -e HEAD 2>/dev/null
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+then
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+ head=HEAD
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+else
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+ head=$(git hash-object -t tree --stdin </dev/null)
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+fi
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+
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+if ! git diff-index --quiet --cached --ignore-submodules $head --
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+then
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+ die "Working directory has staged changes"
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+fi
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+
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+if ! git read-tree -u -m "$commit"
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+then
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+ die "Could not update working tree to new HEAD"
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+fi