Merge branch 'aw/rebase-i-stop-on-failure-to-amend' into maint

* aw/rebase-i-stop-on-failure-to-amend:
rebase -i: interrupt rebase when "commit --amend" failed during "reword"

diff --combined git-rebase--interactive.sh
index 804001bb4e29873ef08d950a40cf1f1745e2aa27,863597c6190bc4bd3f753676595861e80d7cd39b..5812222eb9afa2b2903040d7cf32ab0fb33c3508
--- 1/git-rebase--interactive.sh
--- 2/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@@ -143,6 -143,21 +143,21 @@@ die_with_patch () 
        die "$2"
  }
  
+ exit_with_patch () {
+       echo "$1" > "$state_dir"/stopped-sha
+       make_patch $1
+       git rev-parse --verify HEAD > "$amend"
+       warn "You can amend the commit now, with"
+       warn
+       warn "  git commit --amend"
+       warn
+       warn "Once you are satisfied with your changes, run"
+       warn
+       warn "  git rebase --continue"
+       warn
+       exit $2
+ }
+ 
  die_abort () {
        rm -rf "$state_dir"
        die "$1"
@@@ -161,19 -176,6 +176,19 @@@ do_with_author () 
        )
  }
  
 +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 () {
        ff=--ff
        case "$1" in -n) sha1=$2; ff= ;; *) sha1=$1 ;; esac
@@@ -408,7 -410,13 +423,13 @@@ do_next () 
                mark_action_done
                pick_one $sha1 ||
                        die_with_patch $sha1 "Could not apply $sha1... $rest"
-               git commit --amend --no-post-rewrite
+               git commit --amend --no-post-rewrite || {
+                       warn "Could not amend commit after successfully picking $sha1... $rest"
+                       warn "This is most likely due to an empty commit message, or the pre-commit hook"
+                       warn "failed. If the pre-commit hook failed, you may need to resolve the issue before"
+                       warn "you are able to reword the commit."
+                       exit_with_patch $sha1 1
+               }
                record_in_rewritten $sha1
                ;;
        edit|e)
@@@ -417,19 -425,8 +438,8 @@@
                mark_action_done
                pick_one $sha1 ||
                        die_with_patch $sha1 "Could not apply $sha1... $rest"
-               echo "$sha1" > "$state_dir"/stopped-sha
-               make_patch $sha1
-               git rev-parse --verify HEAD > "$amend"
                warn "Stopped at $sha1... $rest"
-               warn "You can amend the commit now, with"
-               warn
-               warn "  git commit --amend"
-               warn
-               warn "Once you are satisfied with your changes, run"
-               warn
-               warn "  git rebase --continue"
-               warn
-               exit 0
+               exit_with_patch $sha1 0
                ;;
        squash|s|fixup|f)
                case "$command" in
@@@ -845,7 -842,7 +855,7 @@@ has_action "$todo" |
        die_abort "Nothing to do"
  
  cp "$todo" "$todo".backup
 -git_editor "$todo" ||
 +git_sequence_editor "$todo" ||
        die_abort "Could not execute editor"
  
  has_action "$todo" ||