rebase-i-p: only list commits that require rewriting in todo

This is heavily based on Stephan Beyer's git sequencer rewrite of rebase-i-p.

Each commit is still found by rev-list UPSTREAM..HEAD, but a commit is only
included in todo if at least one its parents has been marked for rewriting.

Signed-off-by: Stephen Haberman <stephen@exigencecorp.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 274251f697afc256e249d46376e899ec91011d85..851066f0f47a6c850c649112a88a060fc3ecb99a 100755 (executable)
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -579,18 +579,67 @@ first and then run 'git rebase --continue' again."
                                echo $ONTO > "$REWRITTEN"/$c ||
                                        die "Could not init rewritten commits"
                        done
+                       # No cherry-pick because our first pass is to determine
+                       # parents to rewrite and skipping dropped commits would
+                       # prematurely end our probe
                        MERGES_OPTION=
                else
-                       MERGES_OPTION=--no-merges
+                       MERGES_OPTION="--no-merges --cherry-pick"
                fi
 
                SHORTUPSTREAM=$(git rev-parse --short $UPSTREAM)
                SHORTHEAD=$(git rev-parse --short $HEAD)
                SHORTONTO=$(git rev-parse --short $ONTO)
                git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
-                       --abbrev=7 --reverse --left-right --cherry-pick \
+                       --abbrev=7 --reverse --left-right --topo-order \
                        $UPSTREAM...$HEAD | \
-                       sed -n "s/^>/pick /p" > "$TODO"
+                       sed -n "s/^>//p" | while read shortsha1 rest
+               do
+                       if test t != "$PRESERVE_MERGES"
+                       then
+                               echo "pick $shortsha1 $rest" >> "$TODO"
+                       else
+                               sha1=$(git rev-parse $shortsha1)
+                               preserve=t
+                               for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -f2-)
+                               do
+                                       if test -f "$REWRITTEN"/$p
+                                       then
+                                               preserve=f
+                                       fi
+                               done
+                               if test f = "$preserve"
+                               then
+                                       touch "$REWRITTEN"/$sha1
+                                       echo "pick $shortsha1 $rest" >> "$TODO"
+                               fi
+                       fi
+               done
+
+               # Watch for commits that been dropped by --cherry-pick
+               if test t = "$PRESERVE_MERGES"
+               then
+                       mkdir "$DROPPED"
+                       # Save all non-cherry-picked changes
+                       git rev-list $UPSTREAM...$HEAD --left-right --cherry-pick | \
+                               sed -n "s/^>//p" > "$DOTEST"/not-cherry-picks
+                       # Now all commits and note which ones are missing in
+                       # not-cherry-picks and hence being dropped
+                       git rev-list $UPSTREAM...$HEAD --left-right | \
+                               sed -n "s/^>//p" | while read rev
+                       do
+                               if test -f "$REWRITTEN"/$rev -a "$(grep "$rev" "$DOTEST"/not-cherry-picks)" = ""
+                               then
+                                       # Use -f2 because if rev-list is telling us this commit is
+                                       # not worthwhile, we don't want to track its multiple heads,
+                                       # just the history of its first-parent for others that will
+                                       # be rebasing on top of it
+                                       git rev-list --parents -1 $rev | cut -d' ' -f2 > "$DROPPED"/$rev
+                                       cat "$TODO" | grep -v "${rev:0:7}" > "${TODO}2" ; mv "${TODO}2" "$TODO"
+                                       rm "$REWRITTEN"/$rev
+                               fi
+                       done
+               fi
                test -s "$TODO" || echo noop >> "$TODO"
                cat >> "$TODO" << EOF
 
@@ -606,28 +655,6 @@ first and then run 'git rebase --continue' again."
 #
 EOF
 
-               # Watch for commits that been dropped by --cherry-pick
-               if test t = "$PRESERVE_MERGES"
-               then
-                       mkdir "$DROPPED"
-                       # drop the --cherry-pick parameter this time
-                       git rev-list $MERGES_OPTION --abbrev-commit \
-                               --abbrev=7 $UPSTREAM...$HEAD --left-right | \
-                               sed -n "s/^>//p" | while read rev
-                       do
-                               grep --quiet "$rev" "$TODO"
-                               if [ $? -ne 0 ]
-                               then
-                                       # Use -f2 because if rev-list is telling this commit is not
-                                       # worthwhile, we don't want to track its multiple heads,
-                                       # just the history of its first-parent for others that will
-                                       # be rebasing on top of us
-                                       full=$(git rev-parse $rev)
-                                       git rev-list --parents -1 $rev | cut -d' ' -f2 > "$DROPPED"/$full
-                               fi
-                       done
-               fi
-
                has_action "$TODO" ||
                        die_abort "Nothing to do"