rebase-i: keep old parents when preserving merges

diff --git a/git-am.sh b/git-am.sh
index 1f6b5e02c5e7da45a8e7966b600946cff9c24832..83b277acfdeafa1f745c3c96bc10eef320a2d6ec 100755 (executable)
--- a/git-am.sh
+++ b/git-am.sh
@@ -11,7 +11,7 @@ git-am [options] --skip
 --
 d,dotest=       (removed -- do not use)
 i,interactive   run interactively
-b,binary        pass --allo-binary-replacement to git-apply
+b,binary        pass --allow-binary-replacement to git-apply
 3,3way          allow fall back on 3way merging if needed
 s,signoff       add a Signed-off-by line to the commit message
 u,utf8          recode into utf8 (default)
@@ -30,7 +30,8 @@ set_reflog_action am
 require_work_tree
 cd_to_toplevel
 
-git var GIT_COMMITTER_IDENT >/dev/null || exit
+git var GIT_COMMITTER_IDENT >/dev/null ||
+       die "You need to set your committer info first"
 
 stop_here () {
     echo "$1" >"$dotest/next"
@@ -107,7 +108,7 @@ It does not apply to blobs recorded in its index."
     # patch did not touch, so recursive ends up canceling them,
     # saying that we reverted all those changes.
 
-    eval GITHEAD_$his_tree='"$SUBJECT"'
+    eval GITHEAD_$his_tree='"$FIRSTLINE"'
     export GITHEAD_$his_tree
     git-merge-recursive $orig_tree -- HEAD $his_tree || {
            git rerere
@@ -117,10 +118,6 @@ It does not apply to blobs recorded in its index."
     unset GITHEAD_$his_tree
 }
 
-reread_subject () {
-       git stripspace <"$1" | sed -e 1q
-}
-
 prec=4
 dotest=".dotest"
 sign= utf8=t keep= skip= interactive= resolved= binary= rebasing=
@@ -331,7 +328,20 @@ do
                        echo "Patch is empty.  Was it split wrong?"
                        stop_here $this
                }
-               git stripspace < "$dotest/msg" > "$dotest/msg-clean"
+               if test -f "$dotest/rebasing" &&
+                       commit=$(sed -e 's/^From \([0-9a-f]*\) .*/\1/' \
+                               -e q "$dotest/$msgnum") &&
+                       test "$(git cat-file -t "$commit")" = commit
+               then
+                       git cat-file commit "$commit" |
+                       sed -e '1,/^$/d' >"$dotest/msg-clean"
+               else
+                       SUBJECT="$(sed -n '/^Subject/ s/Subject: //p' "$dotest/info")"
+                       case "$keep_subject" in -k)  SUBJECT="[PATCH] $SUBJECT" ;; esac
+
+                       (printf '%s\n\n' "$SUBJECT"; cat "$dotest/msg") |
+                               git stripspace > "$dotest/msg-clean"
+               fi
                ;;
        esac
 
@@ -347,9 +357,6 @@ do
 
        export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE
 
-       SUBJECT="$(sed -n '/^Subject/ s/Subject: //p' "$dotest/info")"
-       case "$keep_subject" in -k)  SUBJECT="[PATCH] $SUBJECT" ;; esac
-
        case "$resume" in
        '')
            if test '' != "$SIGNOFF"
@@ -357,7 +364,7 @@ do
                LAST_SIGNED_OFF_BY=`
                    sed -ne '/^Signed-off-by: /p' \
                    "$dotest/msg-clean" |
-                   tail -n 1
+                   sed -ne '$p'
                `
                ADD_SIGNOFF=`
                    test "$LAST_SIGNED_OFF_BY" = "$SIGNOFF" || {
@@ -368,10 +375,8 @@ do
                ADD_SIGNOFF=
            fi
            {
-               printf '%s\n' "$SUBJECT"
                if test -s "$dotest/msg-clean"
                then
-                       echo
                        cat "$dotest/msg-clean"
                fi
                if test '' != "$ADD_SIGNOFF"
@@ -408,7 +413,6 @@ do
                [aA]*) action=yes interactive= ;;
                [nN]*) action=skip ;;
                [eE]*) git_editor "$dotest/final-commit"
-                      SUBJECT=$(reread_subject "$dotest/final-commit")
                       action=again ;;
                [vV]*) action=again
                       LESS=-S ${PAGER:-less} "$dotest/patch" ;;
@@ -418,6 +422,7 @@ do
        else
            action=yes
        fi
+       FIRSTLINE=$(sed 1q "$dotest/final-commit")
 
        if test $action = skip
        then
@@ -431,7 +436,7 @@ do
                stop_here $this
        fi
 
-       printf 'Applying %s\n' "$SUBJECT"
+       printf 'Applying %s\n' "$FIRSTLINE"
 
        case "$resolved" in
        '')
@@ -489,7 +494,7 @@ do
        tree=$(git write-tree) &&
        parent=$(git rev-parse --verify HEAD) &&
        commit=$(git commit-tree $tree -p $parent <"$dotest/final-commit") &&
-       git update-ref -m "$GIT_REFLOG_ACTION: $SUBJECT" HEAD $commit $parent ||
+       git update-ref -m "$GIT_REFLOG_ACTION: $FIRSTLINE" HEAD $commit $parent ||
        stop_here $this
 
        if test -x "$GIT_DIR"/hooks/post-applypatch