Add a tool 'git-resurrect.sh <branch>' that tries to find traces of
the <branch> in the HEAD reflog and, optionally, all merge commits in
the repository. It can then resurrect the branch, pointing it at the
most recent of all candidate commits found.
Signed-off-by: Thomas Rast <trast@xxxxxxxxxxxxxxx>
---
Junio C Hamano wrote:
> Do you mean something like this?
>
> sed -n -e "/^$_x40 $_x40 \($_x40\) Merge .*/ {
> s//\1/p
> q
> }"
Yep, precisely. Thanks! This indeed gives it a nice speed boost if
all you want is a topic "resurrection" from pu.
contrib/git-resurrect.sh | 180 ++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 180 insertions(+), 0 deletions(-)
create mode 100755 contrib/git-resurrect.sh
diff --git a/contrib/git-resurrect.sh b/contrib/git-resurrect.sh
new file mode 100755
index 0000000..c364dda
--- /dev/null
+++ b/contrib/git-resurrect.sh
@@ -0,0 +1,180 @@
+#!/bin/sh
+
+USAGE="[-a] [-r] [-m] [-t] [-n] [-b <newname>] <name>"
+LONG_USAGE="git-resurrect attempts to find traces of a branch tip
+called <name>, and tries to resurrect it. Currently, the reflog is
+searched for checkout messages, and with -r also merge messages. With
+-m and -t, the history of all refs is scanned for Merge <name> into
+other/Merge <other> into <name> (respectively) commit subjects, which
+is rather slow but allows you to resurrect other people's topic
+branches."
+
+OPTIONS_SPEC="\
+git resurrect $USAGE
+--
+b,branch= save branch as <newname> instead of <name>
+a,all same as -l -r -m -t
+k,keep-going full rev-list scan (instead of first match)
+l,reflog scan reflog for checkouts (enabled by default)
+r,reflog-merges scan for merges recorded in reflog
+m,merges scan for merges into other branches (slow)
+t,merge-targets scan for merges of other branches into <name>
+n,dry-run don't recreate the branch"
+
+. git-sh-setup
+
+search_reflog () {
+ sed -ne 's~^\([^ ]*\) .*\tcheckout: moving from '"$1"' .*~\1~p' \
+ < "$GIT_DIR"/logs/HEAD
+}
+
+search_reflog_merges () {
+ git rev-parse $(
+ sed -ne 's~^[^ ]* \([^ ]*\) .*\tmerge '"$1"':.*~\1^2~p' \
+ < "$GIT_DIR"/logs/HEAD
+ )
+}
+
+_x40="[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]"
+_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
+
+search_merges () {
+ git rev-list --all --grep="Merge branch '$1'" \
+ --pretty=tformat:"%P %s" |
+ sed -ne "/^$_x40 \($_x40\) Merge .*/ {s//\1/p;$early_exit}"
+}
+
+search_merge_targets () {
+ git rev-list --all --grep="Merge branch '[^']*' into $branch\$" \
+ --pretty=tformat:"%H %s" --all |
+ sed -ne "/^\($_x40\) Merge .*/ {s//\1/p;$early_exit} "
+}
+
+dry_run=
+early_exit=q
+scan_reflog=t
+scan_reflog_merges=
+scan_merges=
+scan_merge_targets=
+new_name=
+
+while test "$#" != 0; do
+ case "$1" in
+ -b|--branch)
+ shift
+ new_name="$1"
+ ;;
+ -n|--dry-run)
+ dry_run=t
+ ;;
+ --no-dry-run)
+ dry_run=
+ ;;
+ -k|--keep-going)
+ early_exit=
+ ;;
+ --no-keep-going)
+ early_exit=q
+ ;;
+ -m|--merges)
+ scan_merges=t
+ ;;
+ --no-merges)
+ scan_merges=
+ ;;
+ -l|--reflog)
+ scan_reflog=t
+ ;;
+ --no-reflog)
+ scan_reflog=
+ ;;
+ -r|--reflog_merges)
+ scan_reflog_merges=t
+ ;;
+ --no-reflog_merges)
+ scan_reflog_merges=
+ ;;
+ -t|--merge-targets)
+ scan_merge_targets=t
+ ;;
+ --no-merge-targets)
+ scan_merge_targets=
+ ;;
+ -a|--all)
+ scan_reflog=t
+ scan_reflog_merges=t
+ scan_merges=t
+ scan_merge_targets=t
+ ;;
+ --)
+ shift
+ break
+ ;;
+ *)
+ usage
+ ;;
+ esac
+ shift
+done
+
+test "$#" = 1 || usage
+
+all_strategies="$scan_reflog$scan_reflog_merges$scan_merges$scan_merge_targets"
+if test -z "$all_strategies"; then
+ die "must enable at least one of -lrmt"
+fi
+
+branch="$1"
+test -z "$new_name" && new_name="$branch"
+
+if test ! -z "$scan_reflog"; then
+ if test -r "$GIT_DIR"/logs/HEAD; then
+ candidates="$(search_reflog $branch)"
+ else
+ die 'reflog scanning requested, but' \
+ '$GIT_DIR/logs/HEAD not readable'
+ fi
+fi
+if test ! -z "$scan_reflog_merges"; then
+ if test -r "$GIT_DIR"/logs/HEAD; then
+ candidates="$candidates $(search_reflog_merges $branch)"
+ else
+ die 'reflog scanning requested, but' \
+ '$GIT_DIR/logs/HEAD not readable'
+ fi
+fi
+if test ! -z "$scan_merges"; then
+ candidates="$candidates $(search_merges $branch)"
+fi
+if test ! -z "$scan_merge_targets"; then
+ candidates="$candidates $(search_merge_targets $branch)"
+fi
+
+candidates="$(git rev-parse $candidates | sort -u)"
+
+if test -z "$candidates"; then
+ hint=
+ test "z$all_strategies" != "ztttt" \
+ && hint=" (maybe try again with -a)"
+ die "no candidates for $branch found$hint"
+fi
+
+echo "** Candidates for $branch **"
+for cmt in $candidates; do
+ git --no-pager log --pretty=tformat:"%ct:%h [%cr] %s" --abbrev-commit -1 $cmt
+done \
+| sort -n | cut -d: -f2-
+
+newest="$(git rev-list -1 $candidates)"
+if test ! -z "$dry_run"; then
+ printf "** Most recent: "
+ git --no-pager log -1 --pretty=tformat:"%h %s" $newest
+elif ! git rev-parse --verify --quiet $new_name >/dev/null; then
+ printf "** Restoring $new_name to "
+ git --no-pager log -1 --pretty=tformat:"%h %s" $newest
+ git branch $new_name $newest
+else
+ printf "Most recent: "
+ git --no-pager log -1 --pretty=tformat:"%h %s" $newest
+ echo "** $new_name already exists, doing nothing"
+fi
--
1.6.1.2.530.gdaa1c
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