foreach i [$w.list.l curselection] {
set b [$w.list.l get $i]
if {[catch {set o [exec git rev-parse --verify $b]}]} continue
if {$delete_branch_checkhead} {
if {[catch {set m [exec git merge-base $o $delete_branch_head]}]} continue
foreach i [$w.list.l curselection] {
set b [$w.list.l get $i]
if {[catch {set o [exec git rev-parse --verify $b]}]} continue
if {$delete_branch_checkhead} {
if {[catch {set m [exec git merge-base $o $delete_branch_head]}]} continue