Rebasage d'une branche comprenant tous ses enfants

J'ai la topologie de référentiel Git suivante:

A-B-F (master)
   \   D (feature-a)
    \ /
     C (feature)
      \
       E (feature-b)

En rebasant la featurebranche, je m'attendais à rebaser tout le sous-arbre (y compris les branches enfants):

$ git rebase feature master

A-B-F (master)
     \   D (feature-a)
      \ /
       C (feature)
        \
         E (feature-b)

Cependant, voici le résultat réel:

      C' (feature)
     /
A-B-F (master)
   \   D (feature-a)
    \ /
     C
      \
       E (feature-b)

Je sais que je peux facilement le réparer manuellement en exécutant:

$ git rebase --onto feature C feature-a
$ git rebase --onto feature C feature-b

Mais existe-t-il un moyen de rebaser automatiquement la branche, y compris tous ses enfants / descendants?

git branch --contains C | \
xargs -n 1 \
git rebase --committer-date-is-author-date --preserve-merges --onto B C^

Il y a quelques années, j'ai écrit quelque chose pour gérer ce genre de choses. (Les commentaires d'amélioration sont bien sûr les bienvenus, mais ne jugez pas trop - c'était il y a longtemps! Je ne connaissais même pas encore Perl!)

Il est destiné à des situations plus statiques - vous le configurez en définissant les paramètres de configuration du formulaire branch.<branch>.autorebaseparent. Il ne touchera aucune branche qui n'a pas ce jeu de paramètres de configuration. Si ce n'est pas ce que vous voulez, vous pouvez probablement le pirater là où vous le souhaitez sans trop de problèmes. Je ne l'ai pas vraiment utilisé au cours des deux dernières années, mais quand je l'ai utilisé, il semblait toujours assez sûr et stable, dans la mesure où cela est possible avec un rebasage automatisé en masse.

Alors voilà. Utilisez-le en l'enregistrant dans un fichier appelé git-auto-rebasedans votre PATH. C'est probablement aussi une bonne idée d'utiliser l' -noption dry run ( ) avant de l'essayer pour de vrai. C'est peut-être un peu plus de détails que vous ne le souhaitez vraiment, mais cela vous montrera ce qu'il va essayer de rebaser, et sur quoi. Cela pourrait vous épargner du chagrin.

#!/bin/bash

CACHE_DIR=.git/auto-rebase
TODO=$CACHE_DIR/todo
TODO_BACKUP=$CACHE_DIR/todo.backup
COMPLETED=$CACHE_DIR/completed
ORIGINAL_BRANCH=$CACHE_DIR/original_branch
REF_NAMESPACE=refs/pre-auto-rebase

print_help() {
    echo "Usage:  git auto-rebase [opts]"
    echo "Options:"
    echo "    -n   dry run"
    echo "    -c   continue previous auto-rebase"
    echo "    -a   abort previous auto-rebase"
    echo "         (leaves completed rebases intact)"
}

cleanup_autorebase() {
    rm -rf $CACHE_DIR
    if [ -n "$dry_run" ]; then
        # The dry run should do nothing here. It doesn't create refs, and won't
        # run unless auto-rebase is empty. Leave this here to catch programming
        # errors, and for possible future -f option.
        git for-each-ref --format="%(refname)" $REF_NAMESPACE |
        while read ref; do
            echo git update-ref -d $ref
        done
    else
        git for-each-ref --format="%(refname)" $REF_NAMESPACE |
        while read ref; do
            git update-ref -d $ref
        done
    fi
}

# Get the rebase relationships from branch.*.autorebaseparent
get_config_relationships() {
    mkdir -p .git/auto-rebase
    # We cannot simply read the indicated parents and blindly follow their
    # instructions; they must form a directed acyclic graph (like git!) which
    # furthermore has no sources with two sinks (i.e. a branch may not be
    # rebased onto two others).
    # 
    # The awk script checks for cycles and double-parents, then sorts first by
    # depth of hierarchy (how many parents it takes to get to a top-level
    # parent), then by parent name. This means that all rebasing onto a given
    # parent happens in a row - convenient for removal of cached refs.
    IFS=$'\n'
    git config --get-regexp 'branch\..+\.autorebaseparent' | \
    awk '{
        child=$1
        sub("^branch[.]","",child)
        sub("[.]autorebaseparent$","",child)
        if (parent[child] != 0) {
            print "Error: branch "child" has more than one parent specified."
            error=1
            exit 1
        }
        parent[child]=$2
    }
    END {
        if ( error != 0 )
            exit error
        # check for cycles
        for (child in parent) {
            delete cache
            depth=0
            cache[child]=1
            cur=child
            while ( parent[cur] != 0 ) {
                depth++
                cur=parent[cur]
                if ( cache[cur] != 0 ) {
                    print "Error: cycle in branch."child".autorebaseparent hierarchy detected"
                    exit 1
                } else {
                    cache[cur]=1
                }
            }
            depths[child]=depth" "parent[child]" "child
        }
        n=asort(depths, children)
        for (i=1; i<=n; i++) {
            sub(".* ","",children[i])
        }
        for (i=1; i<=n; i++) {
            if (parent[children[i]] != 0)
                print parent[children[i]],children[i]
        }
    }' > $TODO

    # Check for any errors. If the awk script's good, this should really check
    # exit codes.
    if grep -q '^Error:' $TODO; then
        cat $TODO
        rm -rf $CACHE_DIR
        exit 1
    fi

    cp $TODO $TODO_BACKUP
}

# Get relationships from config, or if continuing, verify validity of cache
get_relationships() {
    if [ -n "$continue" ]; then
        if [ ! -d $CACHE_DIR ]; then
            echo "Error: You requested to continue a previous auto-rebase, but"
            echo "$CACHE_DIR does not exist."
            exit 1
        fi
        if [ -f $TODO -a -f $TODO_BACKUP -a -f $ORIGINAL_BRANCH ]; then
            if ! cat $COMPLETED $TODO | diff - $TODO_BACKUP; then
                echo "Error: You requested to continue a previous auto-rebase, but the cache appears"
                echo "to be invalid (completed rebases + todo rebases != planned rebases)."
                echo "You may attempt to manually continue from what is stored in $CACHE_DIR"
                echo "or remove it with \"git auto-rebase -a\""
                exit 1
            fi
        else
            echo "Error: You requested to continue a previous auto-rebase, but some cached files"
            echo "are missing."
            echo "You may attempt to manually continue from what is stored in $CACHE_DIR"
            echo "or remove it with \"git auto-rebase -a\""
            exit 1
        fi
    elif [ -d $CACHE_DIR ]; then
        echo "A previous auto-rebase appears to have been left unfinished."
        echo "Either continue it with \"git auto-rebase -c\" or remove the cache with"
        echo "\"git auto-rebase -a\""
        exit 1
    else
        get_config_relationships
    fi
}

# Verify that desired branches exist, and pre-refs do not.
check_ref_existence() {
    local parent child
    for pair in "${pairs[@]}"; do
        parent="${pair% *}"
        if ! git show-ref -q --verify "refs/heads/$parent" > /dev/null ; then
            if ! git show-ref -q --verify "refs/remotes/$parent" > /dev/null; then
                child="${pair#* }"
                echo "Error: specified parent branch $parent of branch $child does not exist"
                exit 1
            fi
        fi
        if [ -z "$continue" ]; then
            if git show-ref -q --verify "$REF_NAMESPACE/$parent" > /dev/null; then
                echo "Error: ref $REF_NAMESPACE/$parent already exists"
                echo "Most likely a previous git-auto-rebase did not complete; if you have fixed all"
                echo "necessary rebases, you may try again after removing it with:"
                echo
                echo "git update-ref -d $REF_NAMESPACE/$parent"
                echo
                exit 1
            fi
        else
            if ! git show-ref -q --verify "$REF_NAMESPACE/$parent" > /dev/null; then
                echo "Error: You requested to continue a previous auto-rebase, but the required"
                echo "cached ref $REF_NAMESPACE/$parent is missing."
                echo "You may attempt to manually continue from the contents of $CACHE_DIR"
                echo "and whatever refs in refs/$REF_NAMESPACE still exist, or abort the previous"
                echo "auto-rebase with \"git auto-rebase -a\""
                exit 1
            fi
        fi
    done
}

# Create the pre-refs, storing original position of rebased parents
create_pre_refs() {
    local parent prev_parent
    for pair in "${pairs[@]}"; do
        parent="${pair% *}"
        if [ "$prev_parent" != "$parent" ]; then
            if [ -n "$dry_run" ]; then
                echo git update-ref "$REF_NAMESPACE/$parent" "$parent" \"\"
            else
                if ! git update-ref "$REF_NAMESPACE/$parent" "$parent" ""; then
                    echo "Error: cannot create ref $REF_NAMESPACE/$parent"
                    exit 1
                fi
            fi
        fi

        prev_parent="$parent"
    done
}

# Perform the rebases, updating todo/completed as we go
perform_rebases() {
    local prev_parent parent child
    for pair in "${pairs[@]}"; do
        parent="${pair% *}"
        child="${pair#* }"

        # We do this *before* rebasing, assuming most likely any failures will be
        # fixed with rebase --continue, and therefore should not be attempted again
        head -n 1 $TODO >> $COMPLETED
        sed -i '1d' $TODO

        if [ -n "$dry_run" ]; then
            echo git rebase --onto "$parent" "$REF_NAMESPACE/$parent" "$child"
            echo "Successfully rebased $child onto $parent"
        else
            echo git rebase --onto "$parent" "$REF_NAMESPACE/$parent" "$child"
            if ( git merge-ff -q "$child" "$parent" 2> /dev/null && echo "Fast-forwarded $child to $parent." ) || \
                git rebase --onto "$parent" "$REF_NAMESPACE/$parent" "$child"; then
                echo "Successfully rebased $child onto $parent"
            else
                echo "Error rebasing $child onto $parent."
                echo 'You should either fix it (end with git rebase --continue) or abort it, then use'
                echo '"git auto-rebase -c" to continue. You may also use "git auto-rebase -a" to'
                echo 'abort the auto-rebase. Note that this will not undo already-completed rebases.'
                exit 1
            fi
        fi

        prev_parent="$parent"
    done
}

rebase_all_intelligent() {
    if ! git rev-parse --show-git-dir &> /dev/null; then
        echo "Error: git-auto-rebase must be run from inside a git repository"
        exit 1
    fi

    SUBDIRECTORY_OK=1
    . "$(git --exec-path | sed 's/:/\n/' | grep -m 1 git-core)"/git-sh-setup
    cd_to_toplevel


    # Figure out what we need to do (continue, or read from config)
    get_relationships

    # Read the resulting todo list
    OLDIFS="$IFS"
    IFS=$'\n'
    pairs=($(cat $TODO))
    IFS="$OLDIFS"

    # Store the original branch
    if [ -z "$continue" ]; then
        git symbolic-ref HEAD | sed 's@refs/heads/@@' > $ORIGINAL_BRANCH
    fi

    check_ref_existence
    # These three depend on the pairs array
    if [ -z "$continue" ]; then
        create_pre_refs
    fi
    perform_rebases

    echo "Returning to original branch"
    if [ -n "$dry_run" ]; then
        echo git checkout $(cat $ORIGINAL_BRANCH)
    else
        git checkout $(cat $ORIGINAL_BRANCH) > /dev/null
    fi

    if diff -q $COMPLETED $TODO_BACKUP ; then
        if [ "$(wc -l $TODO | cut -d" " -f1)" -eq 0 ]; then
            cleanup_autorebase
            echo "Auto-rebase complete"
        else
            echo "Error: todo-rebases not empty, but completed and planned rebases match."
            echo "This should not be possible, unless you hand-edited a cached file."
            echo "Examine $TODO, $TODO_BACKUP, and $COMPLETED to determine what went wrong."
            exit 1
        fi
    else
        echo "Error: completed rebases don't match planned rebases."
        echo "Examine $TODO_BACKUP and $COMPLETED to determine what went wrong."
        exit 1
    fi
}


while getopts "nca" opt; do
    case $opt in
        n ) dry_run=1;;
        c ) continue=1;;
        a ) abort=1;;
        * )
            echo "git-auto-rebase is too dangerous to run with invalid options; exiting"
            print_help
            exit 1
    esac
done
shift $((OPTIND-1))


case $# in
    0 )
        if [ -n "$abort" ]; then
            cleanup_autorebase
        else
            rebase_all_intelligent
        fi
        ;;

    * )
        print_help
        exit 1
        ;;
esac

Une chose que j'ai trouvée, depuis que j'ai abordé cette question à l'origine, est que parfois la réponse est que vous ne vouliez pas du tout rebaser! Il y a quelque chose à dire pour commencer les branches de sujet au bon ancêtre commun en premier lieu, et ne pas essayer de les faire avancer par la suite. Mais c'est entre vous et votre flux de travail.

S'il est nécessaire de mettre à jour une date de validation , la GIT_COMMITTER_DATEvariable d'environnement peut être utilisée ( manuel ). Utilisez également l' --formatoption pour obtenir un nom de branche sans mise en forme supplémentaire.

export GIT_COMMITTER_DATE=$( date -Iseconds )
git branch --format='%(refname)' --contains C | xargs -n 1 | git rebase -p --onto master C^
unset GIT_COMMITTER_DATE
# don't forget to unset this variable to avoid effect for the further work

NB: il est nécessaire de définir soit --committer-date-is-author-dateou GIT_COMMITTER_DATEde garantir la même somme de contrôle pour C', Ca'et Cb'commits (lors du rebasage de la fonction , de la fonction-a et de la fonction-b en conséquence).