git-rebase: add keep_empty flag

Add a command line switch to git-rebase to allow a user the ability to specify
that they want to keep any commits in a series that are empty.

When git-rebase's type is am, then this option will automatically keep any
commit that has a tree object identical to its parent.

This patch changes the default behavior of interactive rebases as well.  With
this patch, git-rebase -i will produce a revision set passed to
git-revision-editor, in which empty commits are commented out.  Empty commits
may be kept manually by uncommenting them.  If the new --keep-empty option is
used in an interactive rebase the empty commits will automatically all be
uncommented in the editor.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 520aaa94fb7b2be7c11e7eed013acf36055a41ab..841ebd6a9f31bf92312b4739b9a3956c1bdcab71 100644 (file)
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -238,6 +238,10 @@ leave out at most one of A and B, in which case it defaults to HEAD.
        will be reset to where it was when the rebase operation was
        started.
 
        will be reset to where it was when the rebase operation was
        started.
 

+--keep-empty::
+       Keep the commits that do not change anything from its
+       parents in the result.
+

 --skip::
        Restart the rebasing process by skipping the current patch.
 
 --skip::
        Restart the rebasing process by skipping the current patch.
 

diff --git a/git-rebase--am.sh b/git-rebase--am.sh
index c815a2412c2f33556ad712d328eaa80241c07bda..04d89415fe8ca1634fa362c66ea9569794dcadd5 100644 (file)
--- a/git-rebase--am.sh
+++ b/git-rebase--am.sh
@@ -20,11 +20,20 @@ esac
 
 test -n "$rebase_root" && root_flag=--root
 
 
 test -n "$rebase_root" && root_flag=--root
 

-git format-patch -k --stdout --full-index --ignore-if-in-upstream \
-       --src-prefix=a/ --dst-prefix=b/ \
-       --no-renames $root_flag "$revisions" |
-git am $git_am_opt --rebasing --resolvemsg="$resolvemsg" &&
-move_to_original_branch
+if test -n "$keep_empty"
+then
+       # we have to do this the hard way.  git format-patch completely squashes
+       # empty commits and even if it didn't the format doesn't really lend
+       # itself well to recording empty patches.  fortunately, cherry-pick
+       # makes this easy
+       git cherry-pick --allow-empty "$revisions"
+else
+       git format-patch -k --stdout --full-index --ignore-if-in-upstream \
+               --src-prefix=a/ --dst-prefix=b/ \
+               --no-renames $root_flag "$revisions" |
+       git am $git_am_opt --rebasing --resolvemsg="$resolvemsg"
+fi && move_to_original_branch
+

 ret=$?
 test 0 != $ret -a -d "$state_dir" && write_basic_state
 exit $ret
 ret=$?
 test 0 != $ret -a -d "$state_dir" && write_basic_state
 exit $ret

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 5812222eb9afa2b2903040d7cf32ab0fb33c3508..70538bb20f39519a7f9aef26605f3f8583df3ad9 100644 (file)
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -167,6 +167,14 @@ has_action () {
        sane_grep '^[^#]' "$1" >/dev/null
 }
 
        sane_grep '^[^#]' "$1" >/dev/null
 }
 

+is_empty_commit() {
+       tree=$(git rev-parse -q --verify "$1"^{tree} 2>/dev/null ||
+               die "$1: not a commit that can be picked")
+       ptree=$(git rev-parse -q --verify "$1"^^{tree} 2>/dev/null ||
+               ptree=4b825dc642cb6eb9a060e54bf8d69288fbee4904)
+       test "$tree" = "$ptree"
+}
+

 # Run command with GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
 # GIT_AUTHOR_DATE exported from the current environment.
 do_with_author () {
 # Run command with GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
 # GIT_AUTHOR_DATE exported from the current environment.
 do_with_author () {


@@ -191,12 +199,19 @@ git_sequence_editor () {
 
 pick_one () {
        ff=--ff
 
 pick_one () {
        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"
        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"

+
+       if is_empty_commit "$sha1"
+       then
+               empty_args="--allow-empty"
+       fi
+

        test -d "$rewritten" &&
                pick_one_preserving_merges "$@" && return
        test -d "$rewritten" &&
                pick_one_preserving_merges "$@" && return

-       output git cherry-pick $ff "$@"
+       output git cherry-pick $empty_args $ff "$@"

 }
 
 pick_one_preserving_merges () {
 }
 
 pick_one_preserving_merges () {


@@ -780,9 +795,17 @@ git rev-list $merges_option --pretty=oneline --abbrev-commit \
        sed -n "s/^>//p" |
 while read -r shortsha1 rest
 do
        sed -n "s/^>//p" |
 while read -r shortsha1 rest
 do

+
+       if test -z "$keep_empty" && is_empty_commit $shortsha1
+       then
+               comment_out="# "
+       else
+               comment_out=
+       fi
+

        if test t != "$preserve_merges"
        then
        if test t != "$preserve_merges"
        then

-               printf '%s\n' "pick $shortsha1 $rest" >> "$todo"
+               printf '%s\n' "${comment_out}pick $shortsha1 $rest" >>"$todo"

        else
                sha1=$(git rev-parse $shortsha1)
                if test -z "$rebase_root"
        else
                sha1=$(git rev-parse $shortsha1)
                if test -z "$rebase_root"


@@ -801,7 +824,7 @@ do
                if test f = "$preserve"
                then
                        touch "$rewritten"/$sha1
                if test f = "$preserve"
                then
                        touch "$rewritten"/$sha1

-                       printf '%s\n' "pick $shortsha1 $rest" >> "$todo"
+                       printf '%s\n' "${comment_out}pick $shortsha1 $rest" >>"$todo"

                fi
        fi
 done
                fi
        fi
 done


@@ -851,6 +874,12 @@ cat >> "$todo" << EOF
 #
 EOF
 
 #
 EOF
 

+if test -z "$keep_empty"
+then
+       echo "# Note that empty commits are commented out" >>"$todo"
+fi
+
+

 has_action "$todo" ||
        die_abort "Nothing to do"
 
 has_action "$todo" ||
        die_abort "Nothing to do"
 

diff --git a/git-rebase.sh b/git-rebase.sh
index 69c1374823084804662dbd6b6d510ec2ec3428e9..24a2840033c175ff5399de82a1a777c75c0e85dd 100755 (executable)
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -43,6 +43,7 @@ s,strategy=!       use the given merge strategy
 no-ff!             cherry-pick all commits, even if unchanged
 m,merge!           use merging strategies to rebase
 i,interactive!     let the user edit the list of commits to rebase
 no-ff!             cherry-pick all commits, even if unchanged
 m,merge!           use merging strategies to rebase
 i,interactive!     let the user edit the list of commits to rebase

+k,keep-empty      preserve empty commits during rebase

 f,force-rebase!    force rebase even if branch is up to date
 X,strategy-option=! pass the argument through to the merge strategy
 stat!              display a diffstat of what changed upstream
 f,force-rebase!    force rebase even if branch is up to date
 X,strategy-option=! pass the argument through to the merge strategy
 stat!              display a diffstat of what changed upstream


@@ -97,6 +98,7 @@ state_dir=
 action=
 preserve_merges=
 autosquash=
 action=
 preserve_merges=
 autosquash=

+keep_empty=

 test "$(git config --bool rebase.autosquash)" = "true" && autosquash=t
 
 read_basic_state () {
 test "$(git config --bool rebase.autosquash)" = "true" && autosquash=t
 
 read_basic_state () {


@@ -220,6 +222,9 @@ do
        -i)
                interactive_rebase=explicit
                ;;
        -i)
                interactive_rebase=explicit
                ;;

+       -k)
+               keep_empty=yes
+               ;;

        -p)
                preserve_merges=t
                test -z "$interactive_rebase" && interactive_rebase=implied
        -p)
                preserve_merges=t
                test -z "$interactive_rebase" && interactive_rebase=implied