Merge branch 'jc/post-simplify' into tr/filter-branch

diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index d04c346e12fb73539e9910951744e9d5558ad4d3..a140337e3558888f625f9656f7c21ea25f64d8be 100755 (executable)
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -97,9 +97,11 @@ USAGE="[--env-filter <command>] [--tree-filter <command>] \
 OPTIONS_SPEC=
 . git-sh-setup
 
-git diff-files --quiet &&
+if [ "$(is_bare_repository)" = false ]; then
+       git diff-files --quiet &&
        git diff-index --cached --quiet HEAD -- ||
        die "Cannot rewrite branch(es) with a dirty working directory."
+fi
 
 tempdir=.git-rewrite
 filter_env=
@@ -315,24 +317,19 @@ 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 next rewritten
-# ancestor(s), i.e. the boundaries in the set of rewritten commits.
+# revision walker.  Fix it by mapping these heads to the unique nearest
+# ancestor that survived the pruning.
 
-# NEEDSWORK: we should sort the unmapped refs topologically first
-while read ref
-do
-       sha1=$(git rev-parse "$ref"^0)
-       test -f "$workdir"/../map/$sha1 && continue
-       # Assign the boundarie(s) in the set of rewritten commits
-       # as the replacement commit(s).
-       # (This would look a bit nicer if --not --stdin worked.)
-       for p in $( (cd "$workdir"/../map; ls | sed "s/^/^/") |
-               git rev-list $ref --boundary --stdin |
-               sed -n "s/^-//p")
+if test "$filter_subdir"
+then
+       while read ref
        do
-               map $p >> "$workdir"/../map/$sha1
-       done
-done < "$tempdir"/heads
+               sha1=$(git rev-parse "$ref"^0)
+               test -f "$workdir"/../map/$sha1 && continue
+               ancestor=$(git rev-list -1 $ref -- "$filter_subdir")
+               test "$ancestor" && echo $(map $ancestor) >> "$workdir"/../map/$sha1
+       done < "$tempdir"/heads
+fi
 
 # Finally update the refs
 
@@ -359,9 +356,17 @@ do
        ;;
        $_x40)
                echo "Ref '$ref' was rewritten"
-               git update-ref -m "filter-branch: rewrite" \
-                               "$ref" $rewritten $sha1 ||
-                       die "Could not rewrite $ref"
+               if ! git update-ref -m "filter-branch: rewrite" \
+                                       "$ref" $rewritten $sha1 2>/dev/null; then
+                       if test $(git cat-file -t "$ref") = tag; then
+                               if test -z "$filter_tag_name"; then
+                                       warn "WARNING: You said to rewrite tagged commits, but not the corresponding tag."
+                                       warn "WARNING: Perhaps use '--tag-name-filter cat' to rewrite the tag."
+                               fi
+                       else
+                               die "Could not rewrite $ref"
+                       fi
+               fi
        ;;
        *)
                # NEEDSWORK: possibly add -Werror, making this an error
@@ -434,18 +439,20 @@ rm -rf "$tempdir"
 
 trap - 0
 
-unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
-test -z "$ORIG_GIT_DIR" || {
-       GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
-}
-test -z "$ORIG_GIT_WORK_TREE" || {
-       GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
-       export GIT_WORK_TREE
-}
-test -z "$ORIG_GIT_INDEX_FILE" || {
-       GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
-       export GIT_INDEX_FILE
-}
-git read-tree -u -m HEAD
+if [ "$(is_bare_repository)" = false ]; then
+       unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
+       test -z "$ORIG_GIT_DIR" || {
+               GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
+       }
+       test -z "$ORIG_GIT_WORK_TREE" || {
+               GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
+               export GIT_WORK_TREE
+       }
+       test -z "$ORIG_GIT_INDEX_FILE" || {
+               GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
+               export GIT_INDEX_FILE
+       }
+       git read-tree -u -m HEAD
+fi
 
 exit $ret