diff --git a/templates/hooks--push-to-checkout.sample b/templates/hooks--push-to-checkout.sample new file mode 100755 index 00000000000..af5a0c0018b --- /dev/null +++ b/templates/hooks--push-to-checkout.sample @@ -0,0 +1,78 @@ +#!/bin/sh + +# An example hook script to update a checked-out tree on a git push. +# +# This hook is invoked by git-receive-pack(1) when it reacts to git +# push and updates reference(s) in its repository, and when the push +# tries to update the branch that is currently checked out and the +# receive.denyCurrentBranch configuration variable is set to +# updateInstead. +# +# By default, such a push is refused if the working tree and the index +# of the remote repository has any difference from the currently +# checked out commit; when both the working tree and the index match +# the current commit, they are updated to match the newly pushed tip +# of the branch. This hook is to be used to override the default +# behaviour; however the code below reimplements the default behaviour +# as a starting point for convenient modification. +# +# The hook receives the commit with which the tip of the current +# branch is going to be updated: +commit=$1 + +# It can exit with a non-zero status to refuse the push (when it does +# so, it must not modify the index or the working tree). +die () { + echo >&2 "$*" + exit 1 +} + +# Or it can make any necessary changes to the working tree and to the +# index to bring them to the desired state when the tip of the current +# branch is updated to the new commit, and exit with a zero status. +# +# For example, the hook can simply run git read-tree -u -m HEAD "$1" +# in order to emulate git fetch that is run in the reverse direction +# with git push, as the two-tree form of git read-tree -u -m is +# essentially the same as git switch or git checkout that switches +# branches while keeping the local changes in the working tree that do +# not interfere with the difference between the branches. + +# The below is a more-or-less exact translation to shell of the C code +# for the default behaviour for git's push-to-checkout hook defined in +# the push_to_deploy() function in builtin/receive-pack.c. +# +# Note that the hook will be executed from the repository directory, +# not from the working tree, so if you want to perform operations on +# the working tree, you will have to adapt your code accordingly, e.g. +# by adding "cd .." or using relative paths. + +if ! git update-index -q --ignore-submodules --refresh +then + die "Up-to-date check failed" +fi + +if ! git diff-files --quiet --ignore-submodules -- +then + die "Working directory has unstaged changes" +fi + +# This is a rough translation of: +# +# head_has_history() ? "HEAD" : EMPTY_TREE_SHA1_HEX +if git cat-file -e HEAD 2>/dev/null +then + head=HEAD +else + head=$(git hash-object -t tree --stdin