lib-rebase.sh: Document what set_fake_editor() does

[git.git] / git-filter-branch.sh

diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index 81392add0b852f51f63a470727c33e0c306260d8..eb62f719b0ad1d015bb116e8447971c5fe7fdba6 100755 (executable)
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -40,6 +40,16 @@ skip_commit()
        done;
 }
 
+# if you run 'git_commit_non_empty_tree "$@"' in a commit filter,
+# it will skip commits that leave the tree untouched, commit the other.
+git_commit_non_empty_tree()
+{
+       if test $# = 3 && test "$1" = $(git rev-parse "$3^{tree}"); then
+               map "$3"
+       else
+               git commit-tree "$@"
+       fi
+}
 # override die(): this version puts in an extra line break, so that
 # the progress is still visible
 
@@ -109,11 +119,12 @@ filter_tree=
 filter_index=
 filter_parent=
 filter_msg=cat
-filter_commit='git commit-tree "$@"'
+filter_commit=
 filter_tag_name=
 filter_subdir=
 orig_namespace=refs/original/
 force=
+prune_empty=
 while :
 do
        case "$1" in
@@ -126,6 +137,11 @@ do
                force=t
                continue
                ;;
+       --prune-empty)
+               shift
+               prune_empty=t
+               continue
+               ;;
        -*)
                ;;
        *)
@@ -176,6 +192,17 @@ do
        esac
 done
 
+case "$prune_empty,$filter_commit" in
+,)
+       filter_commit='git commit-tree "$@"';;
+t,)
+       filter_commit="$functions;"' git_commit_non_empty_tree "$@"';;
+,*)
+       ;;
+*)
+       die "Cannot set --prune-empty and --filter-commit at the same time"
+esac
+
 case "$force" in
 t)
        rm -rf "$tempdir"
@@ -256,7 +283,7 @@ while read commit parents; do
        *)
                # The commit may not have the subdirectory at all
                err=$(git read-tree -i -m $commit:"$filter_subdir" 2>&1) || {
-                       if ! git rev-parse --verify $commit:"$filter_subdir" 2>/dev/null
+                       if ! git rev-parse -q --verify $commit:"$filter_subdir"
                        then
                                rm -f "$GIT_INDEX_FILE"
                        else