compat: fall back on __va_copy if available
[gitweb.git] / git-rebase--interactive.sh
index 5014ae0579753a09d0c52742d0d0ddb8db5ac8c9..5873ba4bc3b2a94cd7754ae572072fd745dc059d 100755 (executable)
@@ -20,6 +20,7 @@ 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
+no-ff              cherry-pick all commits, even if unchanged
 m,merge            always used (no-op)
 i,interactive      always used (no-op)
  Actions:
@@ -27,33 +28,100 @@ 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
+verify             allow pre-rebase hook to run
 root               rebase all reachable commmits up to the root(s)
+autosquash         move commits that begin with squash!/fixup! under -i
 "
 
 . git-sh-setup
 require_work_tree
 
 DOTEST="$GIT_DIR/rebase-merge"
+
+# 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 $DONE.
 TODO="$DOTEST"/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="$DOTEST"/done
+
+# The commit message that is planned to be used for any changes that
+# need to be committed following a user interaction.
 MSG="$DOTEST"/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 $COUNT is the number of commits whose messages have been
+# written to the file so far (including the initial "pick" commit).
+# Each time that a commit message is processed, this line is read and
+# updated.  It is deleted just before the combined commit is made.
 SQUASH_MSG="$DOTEST"/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="$DOTEST"/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
+# $UPSTREAM. They are not necessarily rewritten, but their children
+# might be.  This ensures that commits on merged, but otherwise
+# unrelated side branches are left alone. (Think "X" in the man page's
+# example.)
 REWRITTEN="$DOTEST"/rewritten
+
 DROPPED="$DOTEST"/dropped
+
+# A script to set the GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
+# GIT_AUTHOR_DATE that will be used for the commit that is currently
+# being rebased.
+AUTHOR_SCRIPT="$DOTEST"/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="$DOTEST"/amend
+
+# For the post-rewrite hook, we make a list of rewritten commits and
+# their new sha1s.  The rewritten-pending list keeps the sha1s of
+# commits that have been processed, but not committed yet,
+# e.g. because they are waiting for a 'squash' command.
+REWRITTEN_LIST="$DOTEST"/rewritten-list
+REWRITTEN_PENDING="$DOTEST"/rewritten-pending
+
 PRESERVE_MERGES=
 STRATEGY=
 ONTO=
 VERBOSE=
 OK_TO_SKIP_PRE_REBASE=
 REBASE_ROOT=
+AUTOSQUASH=
+test "$(git config --bool rebase.autosquash)" = "true" && AUTOSQUASH=t
+NEVER_FF=
 
-GIT_CHERRY_PICK_HELP="  After resolving the conflicts,
-mark the corrected paths with 'git add <paths>', and
-run 'git rebase --continue'"
+GIT_CHERRY_PICK_HELP="\
+hint: after resolving the conflicts, mark the corrected paths
+hint: with 'git add <paths>' and run 'git rebase --continue'"
 export GIT_CHERRY_PICK_HELP
 
 warn () {
-       echo "$*" >&2
+       printf '%s\n' "$*" >&2
 }
 
 output () {
@@ -70,6 +138,11 @@ output () {
        esac
 }
 
+# Output the commit message for the specified commit.
+commit_message () {
+       git cat-file commit "$1" | sed "1,/^$/d"
+}
+
 run_pre_rebase_hook () {
        if test -z "$OK_TO_SKIP_PRE_REBASE" &&
           test -x "$GIT_DIR/hooks/pre-rebase"
@@ -81,14 +154,6 @@ run_pre_rebase_hook () {
        fi
 }
 
-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"
 
@@ -129,13 +194,14 @@ 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
+       test -f "$MSG" ||
+               commit_message "$1" > "$MSG"
+       test -f "$AUTHOR_SCRIPT" ||
+               get_author_ident_from_commit "$1" > "$AUTHOR_SCRIPT"
 }
 
 die_with_patch () {
+       echo "$1" > "$DOTEST"/stopped-sha
        make_patch "$1"
        git rerere
        die "$2"
@@ -150,28 +216,28 @@ has_action () {
        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
+               "$@"
+       )
+}
+
 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=$1 ;; esac
+       case "$NEVER_FF" in '') ;; ?*) ff= ;; esac
        output git rev-parse --verify $sha1 || die "Invalid commit name: $sha1"
        test -d "$REWRITTEN" &&
                pick_one_preserving_merges "$@" && return
-       if test ! -z "$REBASE_ROOT"
+       if test -n "$REBASE_ROOT"
        then
                output git cherry-pick "$@"
                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 () {
@@ -191,10 +257,10 @@ pick_one_preserving_merges () {
        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
+                       done <"$DOTEST"/current-commit
                        rm "$DOTEST"/current-commit ||
                        die "Cannot write current commit's replacement sha1"
                fi
@@ -248,9 +314,9 @@ 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" : ' \([^ ]*\)')
@@ -269,18 +335,16 @@ pick_one_preserving_merges () {
                        # redo merge
                        author_script=$(get_author_ident_from_commit $sha1)
                        eval "$author_script"
-                       msg="$(git cat-file commit $sha1 | sed -e '1,/^$/d')"
+                       msg="$(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 $STRATEGY -m "$msg" $new_parents
                        then
                                printf "%s\n" "$msg" > "$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 +364,87 @@ nth_string () {
        esac
 }
 
-make_squash_message () {
+update_squash_messages () {
        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
-               }' <"$SQUASH_MSG"
+               mv "$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
+               commit_message HEAD > "$FIXUP_MSG" || die "Cannot write $FIXUP_MSG"
                COUNT=2
-               echo "# This is a combination of two commits."
-               echo "# The first commit's message is:"
-               echo
-               git cat-file commit HEAD | sed -e '1,/^$/d'
+               {
+                       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 +455,16 @@ 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 +472,9 @@ do_next () {
                mark_action_done
                pick_one $sha1 ||
                        die_with_patch $sha1 "Could not apply $sha1... $rest"
+               echo "$sha1" > "$DOTEST"/stopped-sha
                make_patch $sha1
-               git rev-parse --verify HEAD > "$DOTEST"/amend
+               git rev-parse --verify HEAD > "$AMEND"
                warn "Stopped at $sha1... $rest"
                warn "You can amend the commit now, with"
                warn
@@ -359,51 +486,77 @@ do_next () {
                warn
                exit 0
                ;;
-       squash|s)
-               comment_for_reflog squash
+       squash|s|fixup|f)
+               case "$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"
+                       die "Cannot '$squash_style' without a previous commit"
 
                mark_action_done
-               make_squash_message $sha1 > "$MSG"
-               failed=f
+               update_squash_messages $squash_style $sha1
                author_script=$(get_author_ident_from_commit HEAD)
+               echo "$author_script" > "$AUTHOR_SCRIPT"
+               eval "$author_script"
                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 $sha1 here.
+               git rev-parse --verify HEAD > "$DOTEST"/stopped-sha
+               ${SHELL:-@SHELL_PATH@} -c "$rest" # Actual execution
+               status=$?
+               if test "$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
+                       warn "Execution failed: $rest"
+                       warn "You can fix the problem, and then run"
+                       warn
+                       warn "  git rebase --continue"
+                       warn
+                       exit "$status"
                fi
-               if test $failed = t
+               # Run in subshell because require_clean_work_tree can die.
+               if ! (require_clean_work_tree "rebase")
                then
-                       cp "$MSG" "$GIT_DIR"/MERGE_MSG
+                       warn "Commit or stash your changes, and then run"
+                       warn
+                       warn "  git rebase --continue"
                        warn
-                       warn "Could not apply $sha1... $rest"
-                       die_with_patch $sha1 ""
+                       exit 1
                fi
                ;;
        *)
@@ -433,6 +586,16 @@ do_next () {
                test ! -f "$DOTEST"/verbose ||
                        git diff-tree --stat $(cat "$DOTEST"/head)..HEAD
        } &&
+       {
+               test -s "$REWRITTEN_LIST" &&
+               git notes copy --for-rewrite=rebase < "$REWRITTEN_LIST" ||
+               true # we don't care if this copying failed
+       } &&
+       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 "$DOTEST" &&
        git gc --auto &&
        warn "Successfully rebased and updated $HEADNAME."
@@ -450,24 +613,37 @@ do_rest () {
 # skip picking commits whose parents are unchanged
 skip_unnecessary_picks () {
        fd=3
-       while read command sha1 rest
+       while read -r command rest
        do
                # fd=3 means we skip the command
-               case "$fd,$command,$(git rev-parse --verify --quiet $sha1^)" in
-               3,pick,"$ONTO"*|3,p,"$ONTO"*)
+               case "$fd,$command" in
+               3,pick|3,p)
                        # pick a commit whose parent is current $ONTO -> skip
-                       ONTO=$sha1
+                       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" >&$fd
+               printf '%s\n' "$command${rest:+ }$rest" >&$fd
        done <"$TODO" >"$TODO.new" 3>>"$DONE" &&
-       mv -f "$TODO".new "$TODO" ||
+       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"
 }
 
@@ -487,6 +663,86 @@ get_saved_options () {
        test -f "$DOTEST"/rebase-root && REBASE_ROOT=t
 }
 
+# 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
+
+       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
+               do
+                       case " $used" in
+                       *" $squash "*) continue ;;
+                       esac
+                       emit=0
+                       case "$action" in
+                       +*)
+                               action="${action#+}"
+                               # full sha1 prefix test
+                               case "$msg" in "$sha1"*) emit=1;; esac ;;
+                       *)
+                               # message prefix test
+                               case "$message" in "$msg"*) emit=1;; esac ;;
+                       esac
+                       if test $emit = 1; then
+                               printf '%s\n' "$action $squash $action! $msg"
+                               used="$used$squash "
+                       fi
+               done <"$1.sq"
+       done >"$1.rearranged" <"$1"
+       cat "$1.rearranged" >"$1"
+       rm -f "$1.sq" "$1.rearranged"
+}
+
+LF='
+'
+parse_onto () {
+       case "$1" in
+       *...*)
+               if      left=${1%...*} right=${1#*...} &&
+                       onto=$(git merge-base --all ${left:-HEAD} ${right:-HEAD})
+               then
+                       case "$onto" in
+                       ?*"$LF"?* | '')
+                               exit 1 ;;
+                       esac
+                       echo "$onto"
+                       exit 0
+               fi
+       esac
+       git rev-parse --verify "$1^0"
+}
+
 while test $# != 0
 do
        case "$1" in
@@ -494,6 +750,7 @@ do
                OK_TO_SKIP_PRE_REBASE=yes
                ;;
        --verify)
+               OK_TO_SKIP_PRE_REBASE=
                ;;
        --continue)
                is_standalone "$@" || usage
@@ -514,27 +771,28 @@ do
                then
                        : Nothing to commit -- skip this
                else
-                       . "$DOTEST"/author-script ||
+                       . "$AUTHOR_SCRIPT" ||
                                die "Cannot find the author identity"
                        amend=
-                       if test -f "$DOTEST"/amend
+                       if test -f "$AMEND"
                        then
                                amend=$(git rev-parse --verify HEAD)
-                               test "$amend" = $(cat "$DOTEST"/amend) ||
+                               test "$amend" = $(cat "$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
-                       export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE &&
-                       git commit --no-verify -F "$DOTEST"/message -e || {
+                       do_with_author git commit --no-verify -F "$MSG" -e || {
                                test -n "$amend" && git reset --soft $amend
                                die "Could not commit staged changes."
                        }
                fi
 
-               require_clean_work_tree
+               record_in_rewritten "$(cat "$DOTEST"/stopped-sha)"
+
+               require_clean_work_tree "rebase"
                do_rest
                ;;
        --abort)
@@ -589,12 +847,21 @@ first and then run 'git rebase --continue' again."
        -i)
                # yeah, we know
                ;;
+       --no-ff)
+               NEVER_FF=t
+               ;;
        --root)
                REBASE_ROOT=t
                ;;
+       --autosquash)
+               AUTOSQUASH=t
+               ;;
+       --no-autosquash)
+               AUTOSQUASH=
+               ;;
        --onto)
                shift
-               ONTO=$(git rev-parse --verify "$1") ||
+               ONTO=$(parse_onto "$1") ||
                        die "Does not point to a valid commit: $1"
                ;;
        --)
@@ -623,13 +890,11 @@ first and then run 'git rebase --continue' again."
 
                comment_for_reflog start
 
-               require_clean_work_tree
+               require_clean_work_tree "rebase" "Please commit or stash them."
 
                if test ! -z "$1"
                then
-                       output git show-ref --verify --quiet "refs/heads/$1" ||
-                               die "Invalid branchname: $1"
-                       output git checkout "$1" ||
+                       output git checkout "$1" -- ||
                                die "Could not checkout $1"
                fi
 
@@ -652,13 +917,6 @@ first and then run 'git rebase --continue' again."
                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" &&
@@ -696,11 +954,12 @@ first and then run 'git rebase --continue' again."
                git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
                        --abbrev=7 --reverse --left-right --topo-order \
                        $REVISIONS | \
-                       sed -n "s/^>//p" | while read shortsha1 rest
+                       sed -n "s/^>//p" |
+               while read -r shortsha1 rest
                do
                        if test t != "$PRESERVE_MERGES"
                        then
-                               echo "pick $shortsha1 $rest" >> "$TODO"
+                               printf '%s\n' "pick $shortsha1 $rest" >> "$TODO"
                        else
                                sha1=$(git rev-parse $shortsha1)
                                if test -z "$REBASE_ROOT"
@@ -719,7 +978,7 @@ first and then run 'git rebase --continue' again."
                                if test f = "$preserve"
                                then
                                        touch "$REWRITTEN"/$sha1
-                                       echo "pick $shortsha1 $rest" >> "$TODO"
+                                       printf '%s\n' "pick $shortsha1 $rest" >> "$TODO"
                                fi
                        fi
                done
@@ -751,14 +1010,18 @@ first and then run 'git rebase --continue' again."
                fi
 
                test -s "$TODO" || echo noop >> "$TODO"
+               test -n "$AUTOSQUASH" && rearrange_squash "$TODO"
                cat >> "$TODO" << EOF
 
 # Rebase $SHORTREVISIONS onto $SHORTONTO
 #
 # Commands:
 #  p, pick = use commit
+#  r, reword = use commit, but edit the commit message
 #  e, edit = use commit, but stop for amending
 #  s, squash = use commit, but meld into previous commit
+#  f, fixup = like "squash", but discard this commit's log message
+#  x, exec = run command (the rest of the line) using shell
 #
 # If you remove a line here THAT COMMIT WILL BE LOST.
 # However, if you remove everything, the rebase will be aborted.
@@ -775,10 +1038,11 @@ EOF
                has_action "$TODO" ||
                        die_abort "Nothing to do"
 
-               test -d "$REWRITTEN" || skip_unnecessary_picks
+               test -d "$REWRITTEN" || test -n "$NEVER_FF" || skip_unnecessary_picks
 
+               output git checkout $ONTO || die_abort "could not detach HEAD"
                git update-ref ORIG_HEAD $HEAD
-               output git checkout $ONTO && do_rest
+               do_rest
                ;;
        esac
        shift