Git 1.7.8-rc3
[gitweb.git] / git-rebase--interactive.sh
old mode 100755 (executable)
new mode 100644 (file)
index 314cd36..804001b
 # The original idea comes from Eric W. Biederman, in
 # http://article.gmane.org/gmane.comp.version-control.git/22407
 
-OPTIONS_KEEPDASHDASH=
-OPTIONS_SPEC="\
-git-rebase [-i] [options] [--] <upstream> [<branch>]
-git-rebase [-i] (--continue | --abort | --skip)
---
- Available options are
-v,verbose          display a diffstat of what changed upstream
-onto=              rebase onto given branch instead of upstream
-p,preserve-merges  try to recreate merges instead of ignoring them
-s,strategy=        use the given merge strategy
-m,merge            always used (no-op)
-i,interactive      always used (no-op)
- Actions:
-continue           continue rebasing process
-abort              abort rebasing process and restore original branch
-skip               skip current patch and continue rebasing process
-no-verify          override pre-rebase hook from stopping the operation
-root               rebase all reachable commmits up to the root(s)
-"
-
 . git-sh-setup
-require_work_tree
-
-DOTEST="$GIT_DIR/rebase-merge"
-TODO="$DOTEST"/git-rebase-todo
-DONE="$DOTEST"/done
-MSG="$DOTEST"/message
-SQUASH_MSG="$DOTEST"/message-squash
-REWRITTEN="$DOTEST"/rewritten
-DROPPED="$DOTEST"/dropped
-PRESERVE_MERGES=
-STRATEGY=
-ONTO=
-VERBOSE=
-OK_TO_SKIP_PRE_REBASE=
-REBASE_ROOT=
-
-GIT_CHERRY_PICK_HELP="  After resolving the conflicts,
-mark the corrected paths with 'git add <paths>', and
-run 'git rebase --continue'"
+
+# The file containing rebase commands, comments, and empty lines.
+# This file is created by "git rebase -i" then edited by the user.  As
+# the lines are processed, they are removed from the front of this
+# file and written to the tail of $done.
+todo="$state_dir"/git-rebase-todo
+
+# The rebase command lines that have already been processed.  A line
+# is moved here when it is first handled, before any associated user
+# actions.
+done="$state_dir"/done
+
+# The commit message that is planned to be used for any changes that
+# need to be committed following a user interaction.
+msg="$state_dir"/message
+
+# The file into which is accumulated the suggested commit message for
+# squash/fixup commands.  When the first of a series of squash/fixups
+# is seen, the file is created and the commit message from the
+# previous commit and from the first squash/fixup commit are written
+# to it.  The commit message for each subsequent squash/fixup commit
+# is appended to the file as it is processed.
+#
+# The first line of the file is of the form
+#     # This is a combination of $count commits.
+# where $count is the number of commits whose messages have been
+# written to the file so far (including the initial "pick" commit).
+# Each time that a commit message is processed, this line is read and
+# updated.  It is deleted just before the combined commit is made.
+squash_msg="$state_dir"/message-squash
+
+# If the current series of squash/fixups has not yet included a squash
+# command, then this file exists and holds the commit message of the
+# original "pick" commit.  (If the series ends without a "squash"
+# command, then this can be used as the commit message of the combined
+# commit without opening the editor.)
+fixup_msg="$state_dir"/message-fixup
+
+# $rewritten is the name of a directory containing files for each
+# commit that is reachable by at least one merge base of $head and
+# $upstream. They are not necessarily rewritten, but their children
+# might be.  This ensures that commits on merged, but otherwise
+# unrelated side branches are left alone. (Think "X" in the man page's
+# example.)
+rewritten="$state_dir"/rewritten
+
+dropped="$state_dir"/dropped
+
+# A script to set the GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
+# GIT_AUTHOR_DATE that will be used for the commit that is currently
+# being rebased.
+author_script="$state_dir"/author-script
+
+# When an "edit" rebase command is being processed, the SHA1 of the
+# commit to be edited is recorded in this file.  When "git rebase
+# --continue" is executed, if there are any staged changes then they
+# will be amended to the HEAD commit, but only provided the HEAD
+# commit is still the commit to be edited.  When any other rebase
+# command is processed, this file is deleted.
+amend="$state_dir"/amend
+
+# For the post-rewrite hook, we make a list of rewritten commits and
+# their new sha1s.  The rewritten-pending list keeps the sha1s of
+# commits that have been processed, but not committed yet,
+# e.g. because they are waiting for a 'squash' command.
+rewritten_list="$state_dir"/rewritten-list
+rewritten_pending="$state_dir"/rewritten-pending
+
+GIT_CHERRY_PICK_HELP="$resolvemsg"
 export GIT_CHERRY_PICK_HELP
 
 warn () {
-       echo "$*" >&2
-}
-
-output () {
-       case "$VERBOSE" in
-       '')
-               output=$("$@" 2>&1 )
-               status=$?
-               test $status != 0 && printf "%s\n" "$output"
-               return $status
-               ;;
-       *)
-               "$@"
-               ;;
-       esac
+       printf '%s\n' "$*" >&2
 }
 
-run_pre_rebase_hook () {
-       if test -z "$OK_TO_SKIP_PRE_REBASE" &&
-          test -x "$GIT_DIR/hooks/pre-rebase"
-       then
-               "$GIT_DIR/hooks/pre-rebase" ${1+"$@"} || {
-                       echo >&2 "The pre-rebase hook refused to rebase."
-                       exit 1
-               }
-       fi
+# Output the commit message for the specified commit.
+commit_message () {
+       git cat-file commit "$1" | sed "1,/^$/d"
 }
 
-require_clean_work_tree () {
-       # test if working tree is dirty
-       git rev-parse --verify HEAD > /dev/null &&
-       git update-index --ignore-submodules --refresh &&
-       git diff-files --quiet --ignore-submodules &&
-       git diff-index --cached --quiet HEAD --ignore-submodules -- ||
-       die "Working tree is dirty"
-}
-
-ORIG_REFLOG_ACTION="$GIT_REFLOG_ACTION"
+orig_reflog_action="$GIT_REFLOG_ACTION"
 
 comment_for_reflog () {
-       case "$ORIG_REFLOG_ACTION" in
+       case "$orig_reflog_action" in
        ''|rebase*)
                GIT_REFLOG_ACTION="rebase -i ($1)"
                export GIT_REFLOG_ACTION
@@ -103,16 +104,16 @@ comment_for_reflog () {
 
 last_count=
 mark_action_done () {
-       sed -e 1q < "$TODO" >> "$DONE"
-       sed -e 1d < "$TODO" >> "$TODO".new
-       mv -f "$TODO".new "$TODO"
-       count=$(grep -c '^[^#]' < "$DONE")
-       total=$(($count+$(grep -c '^[^#]' < "$TODO")))
-       if test "$last_count" != "$count"
+       sed -e 1q < "$todo" >> "$done"
+       sed -e 1d < "$todo" >> "$todo".new
+       mv -f "$todo".new "$todo"
+       new_count=$(sane_grep -c '^[^#]' < "$done")
+       total=$(($new_count+$(sane_grep -c '^[^#]' < "$todo")))
+       if test "$last_count" != "$new_count"
        then
-               last_count=$count
-               printf "Rebasing (%d/%d)\r" $count $total
-               test -z "$VERBOSE" || echo
+               last_count=$new_count
+               printf "Rebasing (%d/%d)\r" $new_count $total
+               test -z "$verbose" || echo
        fi
 }
 
@@ -128,50 +129,59 @@ make_patch () {
        *)
                echo "Root commit"
                ;;
-       esac > "$DOTEST"/patch
-       test -f "$DOTEST"/message ||
-               git cat-file commit "$1" | sed "1,/^$/d" > "$DOTEST"/message
-       test -f "$DOTEST"/author-script ||
-               get_author_ident_from_commit "$1" > "$DOTEST"/author-script
+       esac > "$state_dir"/patch
+       test -f "$msg" ||
+               commit_message "$1" > "$msg"
+       test -f "$author_script" ||
+               get_author_ident_from_commit "$1" > "$author_script"
 }
 
 die_with_patch () {
+       echo "$1" > "$state_dir"/stopped-sha
        make_patch "$1"
        git rerere
        die "$2"
 }
 
 die_abort () {
-       rm -rf "$DOTEST"
+       rm -rf "$state_dir"
        die "$1"
 }
 
 has_action () {
-       grep '^[^#]' "$1" >/dev/null
+       sane_grep '^[^#]' "$1" >/dev/null
+}
+
+# Run command with GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
+# GIT_AUTHOR_DATE exported from the current environment.
+do_with_author () {
+       (
+               export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE
+               "$@"
+       )
+}
+
+git_sequence_editor () {
+       if test -z "$GIT_SEQUENCE_EDITOR"
+       then
+               GIT_SEQUENCE_EDITOR="$(git config sequence.editor)"
+               if [ -z "$GIT_SEQUENCE_EDITOR" ]
+               then
+                       GIT_SEQUENCE_EDITOR="$(git var GIT_EDITOR)" || return $?
+               fi
+       fi
+
+       eval "$GIT_SEQUENCE_EDITOR" '"$@"'
 }
 
 pick_one () {
-       no_ff=
-       case "$1" in -n) sha1=$2; no_ff=t ;; *) sha1=$1 ;; esac
+       ff=--ff
+       case "$1" in -n) sha1=$2; ff= ;; *) sha1=$1 ;; esac
+       case "$force_rebase" in '') ;; ?*) ff= ;; esac
        output git rev-parse --verify $sha1 || die "Invalid commit name: $sha1"
-       test -d "$REWRITTEN" &&
+       test -d "$rewritten" &&
                pick_one_preserving_merges "$@" && return
-       if test ! -z "$REBASE_ROOT"
-       then
-               output git cherry-pick "$@"
-               return
-       fi
-       parent_sha1=$(git rev-parse --verify $sha1^) ||
-               die "Could not get the parent of $sha1"
-       current_sha1=$(git rev-parse --verify HEAD)
-       if test "$no_ff$current_sha1" = "$parent_sha1"; then
-               output git reset --hard $sha1
-               test "a$1" = a-n && output git reset --soft $current_sha1
-               sha1=$(git rev-parse --short $sha1)
-               output warn Fast forward to $sha1
-       else
-               output git cherry-pick "$@"
-       fi
+       output git cherry-pick $ff "$@"
 }
 
 pick_one_preserving_merges () {
@@ -187,20 +197,20 @@ pick_one_preserving_merges () {
        esac
        sha1=$(git rev-parse $sha1)
 
-       if test -f "$DOTEST"/current-commit
+       if test -f "$state_dir"/current-commit
        then
                if test "$fast_forward" = t
                then
-                       cat "$DOTEST"/current-commit | while read current_commit
+                       while read current_commit
                        do
-                               git rev-parse HEAD > "$REWRITTEN"/$current_commit
-                       done
-                       rm "$DOTEST"/current-commit ||
+                               git rev-parse HEAD > "$rewritten"/$current_commit
+                       done <"$state_dir"/current-commit
+                       rm "$state_dir"/current-commit ||
                        die "Cannot write current commit's replacement sha1"
                fi
        fi
 
-       echo $sha1 >> "$DOTEST"/current-commit
+       echo $sha1 >> "$state_dir"/current-commit
 
        # rewrite parents; if none were rewritten, we can fast-forward.
        new_parents=
@@ -214,9 +224,9 @@ pick_one_preserving_merges () {
                p=$(expr "$pend" : ' \([^ ]*\)')
                pend="${pend# $p}"
 
-               if test -f "$REWRITTEN"/$p
+               if test -f "$rewritten"/$p
                then
-                       new_p=$(cat "$REWRITTEN"/$p)
+                       new_p=$(cat "$rewritten"/$p)
 
                        # If the todo reordered commits, and our parent is marked for
                        # rewriting, but hasn't been gotten to yet, assume the user meant to
@@ -235,10 +245,10 @@ pick_one_preserving_merges () {
                                ;;
                        esac
                else
-                       if test -f "$DROPPED"/$p
+                       if test -f "$dropped"/$p
                        then
                                fast_forward=f
-                               replacement="$(cat "$DROPPED"/$p)"
+                               replacement="$(cat "$dropped"/$p)"
                                test -z "$replacement" && replacement=root
                                pend=" $replacement$pend"
                        else
@@ -248,9 +258,9 @@ pick_one_preserving_merges () {
        done
        case $fast_forward in
        t)
-               output warn "Fast forward to $sha1"
+               output warn "Fast-forward to $sha1"
                output git reset --hard $sha1 ||
-                       die "Cannot fast forward to $sha1"
+                       die "Cannot fast-forward to $sha1"
                ;;
        f)
                first_parent=$(expr "$new_parents" : ' \([^ ]*\)')
@@ -267,20 +277,19 @@ pick_one_preserving_merges () {
                        test "a$1" = a-n && die "Refusing to squash a merge: $sha1"
 
                        # redo merge
-                       author_script=$(get_author_ident_from_commit $sha1)
-                       eval "$author_script"
-                       msg="$(git cat-file commit $sha1 | sed -e '1,/^$/d')"
+                       author_script_content=$(get_author_ident_from_commit $sha1)
+                       eval "$author_script_content"
+                       msg_content="$(commit_message $sha1)"
                        # No point in merging the first parent, that's HEAD
                        new_parents=${new_parents# $first_parent}
-                       if ! GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
-                               GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
-                               GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
-                               output git merge $STRATEGY -m "$msg" \
-                                       $new_parents
+                       if ! do_with_author output \
+                               git merge --no-ff ${strategy:+-s $strategy} -m \
+                                       "$msg_content" $new_parents
                        then
-                               printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
+                               printf "%s\n" "$msg_content" > "$GIT_DIR"/MERGE_MSG
                                die_with_patch $sha1 "Error redoing merge $sha1"
                        fi
+                       echo "$sha1 $(git rev-parse HEAD^0)" >> "$rewritten_list"
                        ;;
                *)
                        output git cherry-pick "$@" ||
@@ -300,35 +309,87 @@ nth_string () {
        esac
 }
 
-make_squash_message () {
-       if test -f "$SQUASH_MSG"; then
-               COUNT=$(($(sed -n "s/^# This is [^0-9]*\([1-9][0-9]*\).*/\1/p" \
-                       < "$SQUASH_MSG" | sed -ne '$p')+1))
-               echo "# This is a combination of $COUNT commits."
-               sed -e 1d -e '2,/^./{
-                       /^$/d
-               }' <"$SQUASH_MSG"
+update_squash_messages () {
+       if test -f "$squash_msg"; then
+               mv "$squash_msg" "$squash_msg".bak || exit
+               count=$(($(sed -n \
+                       -e "1s/^# This is a combination of \(.*\) commits\./\1/p" \
+                       -e "q" < "$squash_msg".bak)+1))
+               {
+                       echo "# This is a combination of $count commits."
+                       sed -e 1d -e '2,/^./{
+                               /^$/d
+                       }' <"$squash_msg".bak
+               } >"$squash_msg"
        else
-               COUNT=2
-               echo "# This is a combination of two commits."
-               echo "# The first commit's message is:"
-               echo
-               git cat-file commit HEAD | sed -e '1,/^$/d'
+               commit_message HEAD > "$fixup_msg" || die "Cannot write $fixup_msg"
+               count=2
+               {
+                       echo "# This is a combination of 2 commits."
+                       echo "# The first commit's message is:"
+                       echo
+                       cat "$fixup_msg"
+               } >"$squash_msg"
        fi
-       echo
-       echo "# This is the $(nth_string $COUNT) commit message:"
-       echo
-       git cat-file commit $1 | sed -e '1,/^$/d'
+       case $1 in
+       squash)
+               rm -f "$fixup_msg"
+               echo
+               echo "# This is the $(nth_string $count) commit message:"
+               echo
+               commit_message $2
+               ;;
+       fixup)
+               echo
+               echo "# The $(nth_string $count) commit message will be skipped:"
+               echo
+               commit_message $2 | sed -e 's/^/#       /'
+               ;;
+       esac >>"$squash_msg"
 }
 
 peek_next_command () {
-       sed -n "1s/ .*$//p" < "$TODO"
+       sed -n -e "/^#/d" -e '/^$/d' -e "s/ .*//p" -e "q" < "$todo"
+}
+
+# A squash/fixup has failed.  Prepare the long version of the squash
+# commit message, then die_with_patch.  This code path requires the
+# user to edit the combined commit message for all commits that have
+# been squashed/fixedup so far.  So also erase the old squash
+# messages, effectively causing the combined commit to be used as the
+# new basis for any further squash/fixups.  Args: sha1 rest
+die_failed_squash() {
+       mv "$squash_msg" "$msg" || exit
+       rm -f "$fixup_msg"
+       cp "$msg" "$GIT_DIR"/MERGE_MSG || exit
+       warn
+       warn "Could not apply $1... $2"
+       die_with_patch $1 ""
+}
+
+flush_rewritten_pending() {
+       test -s "$rewritten_pending" || return
+       newsha1="$(git rev-parse HEAD^0)"
+       sed "s/$/ $newsha1/" < "$rewritten_pending" >> "$rewritten_list"
+       rm -f "$rewritten_pending"
+}
+
+record_in_rewritten() {
+       oldsha1="$(git rev-parse $1)"
+       echo "$oldsha1" >> "$rewritten_pending"
+
+       case "$(peek_next_command)" in
+       squash|s|fixup|f)
+               ;;
+       *)
+               flush_rewritten_pending
+               ;;
+       esac
 }
 
 do_next () {
-       rm -f "$DOTEST"/message "$DOTEST"/author-script \
-               "$DOTEST"/amend || exit
-       read command sha1 rest < "$TODO"
+       rm -f "$msg" "$author_script" "$amend" || exit
+       read -r command sha1 rest < "$todo"
        case "$command" in
        '#'*|''|noop)
                mark_action_done
@@ -339,6 +400,16 @@ do_next () {
                mark_action_done
                pick_one $sha1 ||
                        die_with_patch $sha1 "Could not apply $sha1... $rest"
+               record_in_rewritten $sha1
+               ;;
+       reword|r)
+               comment_for_reflog reword
+
+               mark_action_done
+               pick_one $sha1 ||
+                       die_with_patch $sha1 "Could not apply $sha1... $rest"
+               git commit --amend --no-post-rewrite
+               record_in_rewritten $sha1
                ;;
        edit|e)
                comment_for_reflog edit
@@ -346,8 +417,9 @@ do_next () {
                mark_action_done
                pick_one $sha1 ||
                        die_with_patch $sha1 "Could not apply $sha1... $rest"
+               echo "$sha1" > "$state_dir"/stopped-sha
                make_patch $sha1
-               git rev-parse --verify HEAD > "$DOTEST"/amend
+               git rev-parse --verify HEAD > "$amend"
                warn "Stopped at $sha1... $rest"
                warn "You can amend the commit now, with"
                warn
@@ -359,78 +431,125 @@ do_next () {
                warn
                exit 0
                ;;
-       squash|s)
-               comment_for_reflog squash
+       squash|s|fixup|f)
+               case "$command" in
+               squash|s)
+                       squash_style=squash
+                       ;;
+               fixup|f)
+                       squash_style=fixup
+                       ;;
+               esac
+               comment_for_reflog $squash_style
 
-               test -f "$DONE" && has_action "$DONE" ||
-                       die "Cannot 'squash' without a previous commit"
+               test -f "$done" && has_action "$done" ||
+                       die "Cannot '$squash_style' without a previous commit"
 
                mark_action_done
-               make_squash_message $sha1 > "$MSG"
-               failed=f
-               author_script=$(get_author_ident_from_commit HEAD)
+               update_squash_messages $squash_style $sha1
+               author_script_content=$(get_author_ident_from_commit HEAD)
+               echo "$author_script_content" > "$author_script"
+               eval "$author_script_content"
                output git reset --soft HEAD^
-               pick_one -n $sha1 || failed=t
+               pick_one -n $sha1 || die_failed_squash $sha1 "$rest"
                case "$(peek_next_command)" in
-               squash|s)
-                       USE_OUTPUT=output
-                       MSG_OPT=-F
-                       EDIT_OR_FILE="$MSG"
-                       cp "$MSG" "$SQUASH_MSG"
+               squash|s|fixup|f)
+                       # This is an intermediate commit; its message will only be
+                       # used in case of trouble.  So use the long version:
+                       do_with_author output git commit --no-verify -F "$squash_msg" ||
+                               die_failed_squash $sha1 "$rest"
                        ;;
                *)
-                       USE_OUTPUT=
-                       MSG_OPT=
-                       EDIT_OR_FILE=-e
-                       rm -f "$SQUASH_MSG" || exit
-                       cp "$MSG" "$GIT_DIR"/SQUASH_MSG
-                       rm -f "$GIT_DIR"/MERGE_MSG || exit
+                       # This is the final command of this squash/fixup group
+                       if test -f "$fixup_msg"
+                       then
+                               do_with_author git commit --no-verify -F "$fixup_msg" ||
+                                       die_failed_squash $sha1 "$rest"
+                       else
+                               cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
+                               rm -f "$GIT_DIR"/MERGE_MSG
+                               do_with_author git commit --no-verify -e ||
+                                       die_failed_squash $sha1 "$rest"
+                       fi
+                       rm -f "$squash_msg" "$fixup_msg"
                        ;;
                esac
-               echo "$author_script" > "$DOTEST"/author-script
-               if test $failed = f
+               record_in_rewritten $sha1
+               ;;
+       x|"exec")
+               read -r command rest < "$todo"
+               mark_action_done
+               printf 'Executing: %s\n' "$rest"
+               # "exec" command doesn't take a sha1 in the todo-list.
+               # => can't just use $sha1 here.
+               git rev-parse --verify HEAD > "$state_dir"/stopped-sha
+               ${SHELL:-@SHELL_PATH@} -c "$rest" # Actual execution
+               status=$?
+               # Run in subshell because require_clean_work_tree can die.
+               dirty=f
+               (require_clean_work_tree "rebase" 2>/dev/null) || dirty=t
+               if test "$status" -ne 0
                then
-                       # This is like --amend, but with a different message
-                       eval "$author_script"
-                       GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
-                       GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
-                       GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
-                       $USE_OUTPUT git commit --no-verify \
-                               $MSG_OPT "$EDIT_OR_FILE" || failed=t
-               fi
-               if test $failed = t
+                       warn "Execution failed: $rest"
+                       test "$dirty" = f ||
+                       warn "and made changes to the index and/or the working tree"
+
+                       warn "You can fix the problem, and then run"
+                       warn
+                       warn "  git rebase --continue"
+                       warn
+                       exit "$status"
+               elif test "$dirty" = t
                then
-                       cp "$MSG" "$GIT_DIR"/MERGE_MSG
+                       warn "Execution succeeded: $rest"
+                       warn "but left changes to the index and/or the working tree"
+                       warn "Commit or stash your changes, and then run"
+                       warn
+                       warn "  git rebase --continue"
                        warn
-                       warn "Could not apply $sha1... $rest"
-                       die_with_patch $sha1 ""
+                       exit 1
                fi
                ;;
        *)
                warn "Unknown command: $command $sha1 $rest"
-               die_with_patch $sha1 "Please fix this in the file $TODO."
+               if git rev-parse --verify -q "$sha1" >/dev/null
+               then
+                       die_with_patch $sha1 "Please fix this in the file $todo."
+               else
+                       die "Please fix this in the file $todo."
+               fi
                ;;
        esac
-       test -s "$TODO" && return
+       test -s "$todo" && return
 
        comment_for_reflog finish &&
-       HEADNAME=$(cat "$DOTEST"/head-name) &&
-       OLDHEAD=$(cat "$DOTEST"/head) &&
-       SHORTONTO=$(git rev-parse --short $(cat "$DOTEST"/onto)) &&
-       NEWHEAD=$(git rev-parse HEAD) &&
-       case $HEADNAME in
+       shortonto=$(git rev-parse --short $onto) &&
+       newhead=$(git rev-parse HEAD) &&
+       case $head_name in
        refs/*)
-               message="$GIT_REFLOG_ACTION: $HEADNAME onto $SHORTONTO)" &&
-               git update-ref -m "$message" $HEADNAME $NEWHEAD $OLDHEAD &&
-               git symbolic-ref HEAD $HEADNAME
+               message="$GIT_REFLOG_ACTION: $head_name onto $shortonto" &&
+               git update-ref -m "$message" $head_name $newhead $orig_head &&
+               git symbolic-ref \
+                 -m "$GIT_REFLOG_ACTION: returning to $head_name" \
+                 HEAD $head_name
                ;;
        esac && {
-               test ! -f "$DOTEST"/verbose ||
-                       git diff-tree --stat $(cat "$DOTEST"/head)..HEAD
+               test ! -f "$state_dir"/verbose ||
+                       git diff-tree --stat $orig_head..HEAD
+       } &&
+       {
+               test -s "$rewritten_list" &&
+               git notes copy --for-rewrite=rebase < "$rewritten_list" ||
+               true # we don't care if this copying failed
        } &&
-       rm -rf "$DOTEST" &&
+       if test -x "$GIT_DIR"/hooks/post-rewrite &&
+               test -s "$rewritten_list"; then
+               "$GIT_DIR"/hooks/post-rewrite rebase < "$rewritten_list"
+               true # we don't care if this hook failed
+       fi &&
+       rm -rf "$state_dir" &&
        git gc --auto &&
-       warn "Successfully rebased and updated $HEADNAME."
+       warn "Successfully rebased and updated $head_name."
 
        exit
 }
@@ -445,336 +564,295 @@ do_rest () {
 # skip picking commits whose parents are unchanged
 skip_unnecessary_picks () {
        fd=3
-       while read command sha1 rest
+       while read -r command rest
        do
                # fd=3 means we skip the command
-               case "$fd,$command,$(git rev-parse --verify --quiet $sha1^)" in
-               3,pick,"$ONTO"*|3,p,"$ONTO"*)
-                       # pick a commit whose parent is current $ONTO -> skip
-                       ONTO=$sha1
+               case "$fd,$command" in
+               3,pick|3,p)
+                       # pick a commit whose parent is current $onto -> skip
+                       sha1=${rest%% *}
+                       case "$(git rev-parse --verify --quiet "$sha1"^)" in
+                       "$onto"*)
+                               onto=$sha1
+                               ;;
+                       *)
+                               fd=1
+                               ;;
+                       esac
                        ;;
-               3,#*|3,,*)
+               3,#*|3,)
                        # copy comments
                        ;;
                *)
                        fd=1
                        ;;
                esac
-               echo "$command${sha1:+ }$sha1${rest:+ }$rest" >&$fd
-       done <"$TODO" >"$TODO.new" 3>>"$DONE" &&
-       mv -f "$TODO".new "$TODO" ||
+               printf '%s\n' "$command${rest:+ }$rest" >&$fd
+       done <"$todo" >"$todo.new" 3>>"$done" &&
+       mv -f "$todo".new "$todo" &&
+       case "$(peek_next_command)" in
+       squash|s|fixup|f)
+               record_in_rewritten "$onto"
+               ;;
+       esac ||
        die "Could not skip unnecessary pick commands"
 }
 
-# check if no other options are set
-is_standalone () {
-       test $# -eq 2 -a "$2" = '--' &&
-       test -z "$ONTO" &&
-       test -z "$PRESERVE_MERGES" &&
-       test -z "$STRATEGY" &&
-       test -z "$VERBOSE"
-}
+# Rearrange the todo list that has both "pick sha1 msg" and
+# "pick sha1 fixup!/squash! msg" appears in it so that the latter
+# comes immediately after the former, and change "pick" to
+# "fixup"/"squash".
+rearrange_squash () {
+       # extract fixup!/squash! lines and resolve any referenced sha1's
+       while read -r pick sha1 message
+       do
+               case "$message" in
+               "squash! "*|"fixup! "*)
+                       action="${message%%!*}"
+                       rest="${message#*! }"
+                       echo "$sha1 $action $rest"
+                       # if it's a single word, try to resolve to a full sha1 and
+                       # emit a second copy. This allows us to match on both message
+                       # and on sha1 prefix
+                       if test "${rest#* }" = "$rest"; then
+                               fullsha="$(git rev-parse -q --verify "$rest" 2>/dev/null)"
+                               if test -n "$fullsha"; then
+                                       # prefix the action to uniquely identify this line as
+                                       # intended for full sha1 match
+                                       echo "$sha1 +$action $fullsha"
+                               fi
+                       fi
+               esac
+       done >"$1.sq" <"$1"
+       test -s "$1.sq" || return
 
-get_saved_options () {
-       test -d "$REWRITTEN" && PRESERVE_MERGES=t
-       test -f "$DOTEST"/strategy && STRATEGY="$(cat "$DOTEST"/strategy)"
-       test -f "$DOTEST"/verbose && VERBOSE=t
-       test -f "$DOTEST"/rebase-root && REBASE_ROOT=t
+       used=
+       while read -r pick sha1 message
+       do
+               case " $used" in
+               *" $sha1 "*) continue ;;
+               esac
+               printf '%s\n' "$pick $sha1 $message"
+               used="$used$sha1 "
+               while read -r squash action msg_content
+               do
+                       case " $used" in
+                       *" $squash "*) continue ;;
+                       esac
+                       emit=0
+                       case "$action" in
+                       +*)
+                               action="${action#+}"
+                               # full sha1 prefix test
+                               case "$msg_content" in "$sha1"*) emit=1;; esac ;;
+                       *)
+                               # message prefix test
+                               case "$message" in "$msg_content"*) emit=1;; esac ;;
+                       esac
+                       if test $emit = 1; then
+                               printf '%s\n' "$action $squash $action! $msg_content"
+                               used="$used$squash "
+                       fi
+               done <"$1.sq"
+       done >"$1.rearranged" <"$1"
+       cat "$1.rearranged" >"$1"
+       rm -f "$1.sq" "$1.rearranged"
 }
 
-while test $# != 0
-do
-       case "$1" in
-       --no-verify)
-               OK_TO_SKIP_PRE_REBASE=yes
-               ;;
-       --verify)
-               ;;
-       --continue)
-               is_standalone "$@" || usage
-               get_saved_options
-               comment_for_reflog continue
-
-               test -d "$DOTEST" || die "No interactive rebase running"
-
-               # Sanity check
-               git rev-parse --verify HEAD >/dev/null ||
-                       die "Cannot read HEAD"
-               git update-index --ignore-submodules --refresh &&
-                       git diff-files --quiet --ignore-submodules ||
-                       die "Working tree is dirty"
-
-               # do we have anything to commit?
-               if git diff-index --cached --quiet --ignore-submodules HEAD --
+case "$action" in
+continue)
+       # do we have anything to commit?
+       if git diff-index --cached --quiet --ignore-submodules HEAD --
+       then
+               : Nothing to commit -- skip this
+       else
+               if ! test -f "$author_script"
                then
-                       : Nothing to commit -- skip this
-               else
-                       . "$DOTEST"/author-script ||
-                               die "Cannot find the author identity"
-                       amend=
-                       if test -f "$DOTEST"/amend
-                       then
-                               amend=$(git rev-parse --verify HEAD)
-                               test "$amend" = $(cat "$DOTEST"/amend) ||
-                               die "\
-You have uncommitted changes in your working tree. Please, commit them
-first and then run 'git rebase --continue' again."
-                               git reset --soft HEAD^ ||
-                               die "Cannot rewind the HEAD"
-                       fi
-                       export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE &&
-                       git commit --no-verify -F "$DOTEST"/message -e || {
-                               test -n "$amend" && git reset --soft $amend
-                               die "Could not commit staged changes."
-                       }
-               fi
+                       die "You have staged changes in your working tree. If these changes are meant to be
+squashed into the previous commit, run:
 
-               require_clean_work_tree
-               do_rest
-               ;;
-       --abort)
-               is_standalone "$@" || usage
-               get_saved_options
-               comment_for_reflog abort
-
-               git rerere clear
-               test -d "$DOTEST" || die "No interactive rebase running"
-
-               HEADNAME=$(cat "$DOTEST"/head-name)
-               HEAD=$(cat "$DOTEST"/head)
-               case $HEADNAME in
-               refs/*)
-                       git symbolic-ref HEAD $HEADNAME
-                       ;;
-               esac &&
-               output git reset --hard $HEAD &&
-               rm -rf "$DOTEST"
-               exit
-               ;;
-       --skip)
-               is_standalone "$@" || usage
-               get_saved_options
-               comment_for_reflog skip
+  git commit --amend
 
-               git rerere clear
-               test -d "$DOTEST" || die "No interactive rebase running"
+If they are meant to go into a new commit, run:
 
-               output git reset --hard && do_rest
-               ;;
-       -s)
-               case "$#,$1" in
-               *,*=*)
-                       STRATEGY="-s "$(expr "z$1" : 'z-[^=]*=\(.*\)') ;;
-               1,*)
-                       usage ;;
-               *)
-                       STRATEGY="-s $2"
-                       shift ;;
-               esac
-               ;;
-       -m)
-               # we use merge anyway
-               ;;
-       -v)
-               VERBOSE=t
-               ;;
-       -p)
-               PRESERVE_MERGES=t
-               ;;
-       -i)
-               # yeah, we know
-               ;;
-       --root)
-               REBASE_ROOT=t
-               ;;
-       --onto)
-               shift
-               ONTO=$(git rev-parse --verify "$1") ||
-                       die "Does not point to a valid commit: $1"
-               ;;
-       --)
-               shift
-               test -z "$REBASE_ROOT" -a $# -ge 1 -a $# -le 2 ||
-               test ! -z "$REBASE_ROOT" -a $# -le 1 || usage
-               test -d "$DOTEST" &&
-                       die "Interactive rebase already started"
+  git commit
 
-               git var GIT_COMMITTER_IDENT >/dev/null ||
-                       die "You need to set your committer info first"
+In both case, once you're done, continue with:
 
-               if test -z "$REBASE_ROOT"
+  git rebase --continue
+"
+               fi
+               . "$author_script" ||
+                       die "Error trying to find the author identity to amend commit"
+               current_head=
+               if test -f "$amend"
                then
-                       UPSTREAM_ARG="$1"
-                       UPSTREAM=$(git rev-parse --verify "$1") || die "Invalid base"
-                       test -z "$ONTO" && ONTO=$UPSTREAM
-                       shift
-               else
-                       UPSTREAM=
-                       UPSTREAM_ARG=--root
-                       test -z "$ONTO" &&
-                               die "You must specify --onto when using --root"
+                       current_head=$(git rev-parse --verify HEAD)
+                       test "$current_head" = $(cat "$amend") ||
+                       die "\
+You have uncommitted changes in your working tree. Please, commit them
+first and then run 'git rebase --continue' again."
+                       git reset --soft HEAD^ ||
+                       die "Cannot rewind the HEAD"
                fi
-               run_pre_rebase_hook "$UPSTREAM_ARG" "$@"
+               do_with_author git commit --no-verify -F "$msg" -e || {
+                       test -n "$current_head" && git reset --soft $current_head
+                       die "Could not commit staged changes."
+               }
+       fi
 
-               comment_for_reflog start
+       record_in_rewritten "$(cat "$state_dir"/stopped-sha)"
 
-               require_clean_work_tree
+       require_clean_work_tree "rebase"
+       do_rest
+       ;;
+skip)
+       git rerere clear
 
-               if test ! -z "$1"
-               then
-                       output git show-ref --verify --quiet "refs/heads/$1" ||
-                               die "Invalid branchname: $1"
-                       output git checkout "$1" ||
-                               die "Could not checkout $1"
-               fi
+       do_rest
+       ;;
+esac
 
-               HEAD=$(git rev-parse --verify HEAD) || die "No HEAD?"
-               mkdir "$DOTEST" || die "Could not create temporary $DOTEST"
+git var GIT_COMMITTER_IDENT >/dev/null ||
+       die "You need to set your committer info first"
 
-               : > "$DOTEST"/interactive || die "Could not mark as interactive"
-               git symbolic-ref HEAD > "$DOTEST"/head-name 2> /dev/null ||
-                       echo "detached HEAD" > "$DOTEST"/head-name
+comment_for_reflog start
 
-               echo $HEAD > "$DOTEST"/head
-               case "$REBASE_ROOT" in
-               '')
-                       rm -f "$DOTEST"/rebase-root ;;
-               *)
-                       : >"$DOTEST"/rebase-root ;;
-               esac
-               echo $ONTO > "$DOTEST"/onto
-               test -z "$STRATEGY" || echo "$STRATEGY" > "$DOTEST"/strategy
-               test t = "$VERBOSE" && : > "$DOTEST"/verbose
-               if test t = "$PRESERVE_MERGES"
-               then
-                       # $REWRITTEN contains files for each commit that is
-                       # reachable by at least one merge base of $HEAD and
-                       # $UPSTREAM. They are not necessarily rewritten, but
-                       # their children might be.
-                       # This ensures that commits on merged, but otherwise
-                       # unrelated side branches are left alone. (Think "X"
-                       # in the man page's example.)
-                       if test -z "$REBASE_ROOT"
-                       then
-                               mkdir "$REWRITTEN" &&
-                               for c in $(git merge-base --all $HEAD $UPSTREAM)
-                               do
-                                       echo $ONTO > "$REWRITTEN"/$c ||
-                                               die "Could not init rewritten commits"
-                               done
-                       else
-                               mkdir "$REWRITTEN" &&
-                               echo $ONTO > "$REWRITTEN"/root ||
-                                       die "Could not init rewritten commits"
-                       fi
-                       # No cherry-pick because our first pass is to determine
-                       # parents to rewrite and skipping dropped commits would
-                       # prematurely end our probe
-                       MERGES_OPTION=
-                       first_after_upstream="$(git rev-list --reverse --first-parent $UPSTREAM..$HEAD | head -n 1)"
-               else
-                       MERGES_OPTION="--no-merges --cherry-pick"
-               fi
+if test ! -z "$switch_to"
+then
+       output git checkout "$switch_to" -- ||
+               die "Could not checkout $switch_to"
+fi
 
-               SHORTHEAD=$(git rev-parse --short $HEAD)
-               SHORTONTO=$(git rev-parse --short $ONTO)
-               if test -z "$REBASE_ROOT"
-                       # this is now equivalent to ! -z "$UPSTREAM"
-               then
-                       SHORTUPSTREAM=$(git rev-parse --short $UPSTREAM)
-                       REVISIONS=$UPSTREAM...$HEAD
-                       SHORTREVISIONS=$SHORTUPSTREAM..$SHORTHEAD
-               else
-                       REVISIONS=$ONTO...$HEAD
-                       SHORTREVISIONS=$SHORTHEAD
-               fi
-               git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
-                       --abbrev=7 --reverse --left-right --topo-order \
-                       $REVISIONS | \
-                       sed -n "s/^>//p" | while read shortsha1 rest
+orig_head=$(git rev-parse --verify HEAD) || die "No HEAD?"
+mkdir "$state_dir" || die "Could not create temporary $state_dir"
+
+: > "$state_dir"/interactive || die "Could not mark as interactive"
+write_basic_state
+if test t = "$preserve_merges"
+then
+       if test -z "$rebase_root"
+       then
+               mkdir "$rewritten" &&
+               for c in $(git merge-base --all $orig_head $upstream)
                do
-                       if test t != "$PRESERVE_MERGES"
-                       then
-                               echo "pick $shortsha1 $rest" >> "$TODO"
-                       else
-                               sha1=$(git rev-parse $shortsha1)
-                               if test -z "$REBASE_ROOT"
-                               then
-                                       preserve=t
-                                       for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)
-                                       do
-                                               if test -f "$REWRITTEN"/$p -a \( $p != $UPSTREAM -o $sha1 = $first_after_upstream \)
-                                               then
-                                                       preserve=f
-                                               fi
-                                       done
-                               else
-                                       preserve=f
-                               fi
-                               if test f = "$preserve"
-                               then
-                                       touch "$REWRITTEN"/$sha1
-                                       echo "pick $shortsha1 $rest" >> "$TODO"
-                               fi
-                       fi
+                       echo $onto > "$rewritten"/$c ||
+                               die "Could not init rewritten commits"
                done
-
-               # Watch for commits that been dropped by --cherry-pick
-               if test t = "$PRESERVE_MERGES"
+       else
+               mkdir "$rewritten" &&
+               echo $onto > "$rewritten"/root ||
+                       die "Could not init rewritten commits"
+       fi
+       # No cherry-pick because our first pass is to determine
+       # parents to rewrite and skipping dropped commits would
+       # prematurely end our probe
+       merges_option=
+else
+       merges_option="--no-merges --cherry-pick"
+fi
+
+shorthead=$(git rev-parse --short $orig_head)
+shortonto=$(git rev-parse --short $onto)
+if test -z "$rebase_root"
+       # this is now equivalent to ! -z "$upstream"
+then
+       shortupstream=$(git rev-parse --short $upstream)
+       revisions=$upstream...$orig_head
+       shortrevisions=$shortupstream..$shorthead
+else
+       revisions=$onto...$orig_head
+       shortrevisions=$shorthead
+fi
+git rev-list $merges_option --pretty=oneline --abbrev-commit \
+       --abbrev=7 --reverse --left-right --topo-order \
+       $revisions | \
+       sed -n "s/^>//p" |
+while read -r shortsha1 rest
+do
+       if test t != "$preserve_merges"
+       then
+               printf '%s\n' "pick $shortsha1 $rest" >> "$todo"
+       else
+               sha1=$(git rev-parse $shortsha1)
+               if test -z "$rebase_root"
                then
-                       mkdir "$DROPPED"
-                       # Save all non-cherry-picked changes
-                       git rev-list $REVISIONS --left-right --cherry-pick | \
-                               sed -n "s/^>//p" > "$DOTEST"/not-cherry-picks
-                       # Now all commits and note which ones are missing in
-                       # not-cherry-picks and hence being dropped
-                       git rev-list $REVISIONS |
-                       while read rev
+                       preserve=t
+                       for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)
                        do
-                               if test -f "$REWRITTEN"/$rev -a "$(grep "$rev" "$DOTEST"/not-cherry-picks)" = ""
+                               if test -f "$rewritten"/$p
                                then
-                                       # Use -f2 because if rev-list is telling us this commit is
-                                       # not worthwhile, we don't want to track its multiple heads,
-                                       # just the history of its first-parent for others that will
-                                       # be rebasing on top of it
-                                       git rev-list --parents -1 $rev | cut -d' ' -s -f2 > "$DROPPED"/$rev
-                                       short=$(git rev-list -1 --abbrev-commit --abbrev=7 $rev)
-                                       grep -v "^[a-z][a-z]* $short" <"$TODO" > "${TODO}2" ; mv "${TODO}2" "$TODO"
-                                       rm "$REWRITTEN"/$rev
+                                       preserve=f
                                fi
                        done
+               else
+                       preserve=f
+               fi
+               if test f = "$preserve"
+               then
+                       touch "$rewritten"/$sha1
+                       printf '%s\n' "pick $shortsha1 $rest" >> "$todo"
                fi
+       fi
+done
+
+# Watch for commits that been dropped by --cherry-pick
+if test t = "$preserve_merges"
+then
+       mkdir "$dropped"
+       # Save all non-cherry-picked changes
+       git rev-list $revisions --left-right --cherry-pick | \
+               sed -n "s/^>//p" > "$state_dir"/not-cherry-picks
+       # Now all commits and note which ones are missing in
+       # not-cherry-picks and hence being dropped
+       git rev-list $revisions |
+       while read rev
+       do
+               if test -f "$rewritten"/$rev -a "$(sane_grep "$rev" "$state_dir"/not-cherry-picks)" = ""
+               then
+                       # Use -f2 because if rev-list is telling us this commit is
+                       # not worthwhile, we don't want to track its multiple heads,
+                       # just the history of its first-parent for others that will
+                       # be rebasing on top of it
+                       git rev-list --parents -1 $rev | cut -d' ' -s -f2 > "$dropped"/$rev
+                       short=$(git rev-list -1 --abbrev-commit --abbrev=7 $rev)
+                       sane_grep -v "^[a-z][a-z]* $short" <"$todo" > "${todo}2" ; mv "${todo}2" "$todo"
+                       rm "$rewritten"/$rev
+               fi
+       done
+fi
 
-               test -s "$TODO" || echo noop >> "$TODO"
-               cat >> "$TODO" << EOF
+test -s "$todo" || echo noop >> "$todo"
+test -n "$autosquash" && rearrange_squash "$todo"
+cat >> "$todo" << EOF
 
-# Rebase $SHORTREVISIONS onto $SHORTONTO
+# Rebase $shortrevisions onto $shortonto
 #
 # Commands:
 #  p, pick = use commit
+#  r, reword = use commit, but edit the commit message
 #  e, edit = use commit, but stop for amending
 #  s, squash = use commit, but meld into previous commit
+#  f, fixup = like "squash", but discard this commit's log message
+#  x, exec = run command (the rest of the line) using shell
 #
 # If you remove a line here THAT COMMIT WILL BE LOST.
 # However, if you remove everything, the rebase will be aborted.
 #
 EOF
 
-               has_action "$TODO" ||
-                       die_abort "Nothing to do"
+has_action "$todo" ||
+       die_abort "Nothing to do"
 
-               cp "$TODO" "$TODO".backup
-               git_editor "$TODO" ||
-                       die "Could not execute editor"
+cp "$todo" "$todo".backup
+git_sequence_editor "$todo" ||
+       die_abort "Could not execute editor"
 
-               has_action "$TODO" ||
-                       die_abort "Nothing to do"
+has_action "$todo" ||
+       die_abort "Nothing to do"
 
-               test -d "$REWRITTEN" || skip_unnecessary_picks
+test -d "$rewritten" || test -n "$force_rebase" || skip_unnecessary_picks
 
-               git update-ref ORIG_HEAD $HEAD
-               output git checkout $ONTO && do_rest
-               ;;
-       esac
-       shift
-done
+output git checkout $onto || die_abort "could not detach HEAD"
+git update-ref ORIG_HEAD $orig_head
+do_rest