Merge branch 'tr/maint-merge-ours-clarification' (early part)

diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index 37e044db40bb89470bb64a4108c86d5173e03b5a..6b8b6a4f26a60c325a2c76e1d5b0e747b9d1d99b 100755 (executable)
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -97,12 +97,12 @@ set_ident () {
        echo "case \"\$GIT_${uid}_NAME\" in \"\") GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\" && export GIT_${uid}_NAME;; esac"
 }
 
-USAGE="[--env-filter <command>] [--tree-filter <command>] \
-[--index-filter <command>] [--parent-filter <command>] \
-[--msg-filter <command>] [--commit-filter <command>] \
-[--tag-name-filter <command>] [--subdirectory-filter <directory>] \
-[--original <namespace>] [-d <directory>] [-f | --force] \
-[<rev-list options>...]"
+USAGE="[--env-filter <command>] [--tree-filter <command>]
+            [--index-filter <command>] [--parent-filter <command>]
+            [--msg-filter <command>] [--commit-filter <command>]
+            [--tag-name-filter <command>] [--subdirectory-filter <directory>]
+            [--original <namespace>] [-d <directory>] [-f | --force]
+            [<rev-list options>...]"
 
 OPTIONS_SPEC=
 . git-sh-setup
@@ -125,6 +125,7 @@ filter_subdir=
 orig_namespace=refs/original/
 force=
 prune_empty=
+remap_to_ancestor=
 while :
 do
        case "$1" in
@@ -137,6 +138,11 @@ do
                force=t
                continue
                ;;
+       --remap-to-ancestor)
+               shift
+               remap_to_ancestor=t
+               continue
+               ;;
        --prune-empty)
                shift
                prune_empty=t
@@ -182,6 +188,7 @@ do
                ;;
        --subdirectory-filter)
                filter_subdir="$OPTARG"
+               remap_to_ancestor=t
                ;;
        --original)
                orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
@@ -257,15 +264,24 @@ git read-tree || die "Could not seed the index"
 # map old->new commit ids for rewriting parents
 mkdir ../map || die "Could not create map/ directory"
 
+# we need "--" only if there are no path arguments in $@
+nonrevs=$(git rev-parse --no-revs "$@") || exit
+test -z "$nonrevs" && dashdash=-- || dashdash=
+rev_args=$(git rev-parse --revs-only "$@")
+
 case "$filter_subdir" in
 "")
-       git rev-list --reverse --topo-order --default HEAD \
-               --parents --simplify-merges "$@"
+       eval set -- "$(git rev-parse --sq --no-revs "$@")"
        ;;
 *)
-       git rev-list --reverse --topo-order --default HEAD \
-               --parents --simplify-merges "$@" -- "$filter_subdir"
-esac > ../revs || die "Could not get the commits"
+       eval set -- "$(git rev-parse --sq --no-revs "$@" $dashdash \
+               "$filter_subdir")"
+       ;;
+esac
+
+git rev-list --reverse --topo-order --default HEAD \
+       --parents --simplify-merges $rev_args "$@" > ../revs ||
+       die "Could not get the commits"
 commits=$(wc -l <../revs | tr -d " ")
 
 test $commits -eq 0 && die "Found nothing to rewrite"
@@ -345,19 +361,19 @@ while read commit parents; do
                        die "could not write rewritten commit"
 done <../revs
 
-# In case of a subdirectory filter, it is possible that a specified head
-# is not in the set of rewritten commits, because it was pruned by the
-# revision walker.  Fix it by mapping these heads to the unique nearest
-# ancestor that survived the pruning.
+# If we are filtering for paths, as in the case of a subdirectory
+# filter, it is possible that a specified head is not in the set of
+# rewritten commits, because it was pruned by the revision walker.
+# Ancestor remapping fixes this by mapping these heads to the unique
+# nearest ancestor that survived the pruning.
 
-if test "$filter_subdir"
+if test "$remap_to_ancestor" = t
 then
        while read ref
        do
                sha1=$(git rev-parse "$ref"^0)
                test -f "$workdir"/../map/$sha1 && continue
-               ancestor=$(git rev-list --simplify-merges -1 \
-                               $ref -- "$filter_subdir")
+               ancestor=$(git rev-list --simplify-merges -1 "$ref" "$@")
                test "$ancestor" && echo $(map $ancestor) >> "$workdir"/../map/$sha1
        done < "$tempdir"/heads
 fi