Meta/Reintegrate: work on a detached head

diff --git a/Reintegrate b/Reintegrate
index db914c698702ca97a3bede14dc89e4323b5ca028..63340a9db583a70015683d40c1fe8dc15b9ed26e 100755 (executable)
--- a/Reintegrate
+++ b/Reintegrate
@@ -164,7 +164,33 @@ no)
                prev_cut=
        }
 
+       detach () {
+               if original_branch=$(git symbolic-ref HEAD 2>/dev/null)
+               then
+                       original_branch=${original_branch#refs/heads/}
+                       git checkout --quiet --detach
+                       into="--into $original_branch"
+               else
+                       original_branch=
+                       into=
+               fi
+
+       }
+
+       leave () {
+               if test -n "$original_branch" && ! git symbolic-ref HEAD 2>/dev/null
+               then
+                       git checkout --quiet -B "$original_branch"
+               fi
+               if test -n "$1"
+               then
+                       exit "$1"
+               fi
+       }
+
+       detach
        cut_seen=0 prev_cut= count_since_last_cut=0 cocci_count=0
+
        while read branch eh
        do
                case "$branch" in '###') cut_seen=$(( $cut_seen + 1 )) ;; esac
@@ -206,13 +232,13 @@ no)
                                cat contrib/coccinelle/*.patch >cocci.patch
                                if ! test -s cocci.patch
                                then
-                                       exit 0
+                                       leave 0
                                fi
-                               git apply --index -3 cocci.patch || exit
+                               git apply --index -3 cocci.patch || leave $?
                                rm cocci.patch
                                git diff --quiet HEAD && continue
                        fi
-                       git commit -m "$cocci_mark" || exit
+                       git commit -m "$cocci_mark" || leave $?
 
                        mark_cut
                        continue
@@ -228,7 +254,7 @@ no)
                        save=$(git rev-parse --verify HEAD) &&
                        tip=$(git rev-parse --verify "$branch^0") &&
                        mb=$(git merge-base "$tip" "$save") ||
-                       exit
+                       leave $?
 
                        test "$mb" = "$tip" && continue
 
@@ -237,13 +263,13 @@ no)
 
                        rebuild=$(git config "branch.$branch.rebuild" || :)
 
-                       GIT_EDITOR=: git merge --no-ff $rebuild $accept_rerere --edit "$branch" ||
+                       GIT_EDITOR=: git merge --no-ff $into $rebuild $accept_rerere --edit "$branch" ||
                        accept_rerere ||
-                       exit
+                       leave $?
 
-                       annotate_merge "$branch" || exit
+                       annotate_merge "$branch" || leave $?
                        test -z "$edit" ||
-                       git commit --amend || exit
+                       git commit --amend || leave $?
 
                        this=$(git rev-parse --verify HEAD)
                        if test "$this" = "$save"
@@ -254,7 +280,7 @@ no)
                                echo >&2 "Fixing up the merge"
                                git cherry-pick --no-commit "refs/merge-fix/$branch" &&
                                git diff --stat HEAD &&
-                               GIT_EDITOR=: git commit --amend -a || exit
+                               GIT_EDITOR=: git commit --amend -a || leave $?
                        fi
                        ;;
                pick" "*)
@@ -262,13 +288,14 @@ no)
 
                        mark_cut
 
-                       git cherry-pick "$branch" || exit ;;
-               *) echo >&2 "Eh? $branch $eh"; exit ;;
+                       git cherry-pick "$branch" || leave $? ;;
+               *) echo >&2 "Eh? $branch $eh"; leave $? ;;
                esac
 
-               eval "$exec" || exit
+               eval "$exec" || leave $?
        done
-       exit
+       leave $?
+       ;;
 esac
 
 if test -n "$update" && test $# = 0