gitk: Avoid an error when cherry-picking if HEAD has moved on

diff --git a/gitk b/gitk
index 06172a434b64c330a260596a8dd187a20577638a..f910cba8bfdea13345c6c504e73cd214b601e38d 100755 (executable)
--- a/gitk
+++ b/gitk
@@ -6648,7 +6648,7 @@ proc addnewchild {id p} {
     global arcnos arcids arctags arcout arcend arcstart archeads growing
     global seeds allcommits
 
-    if {![info exists allcommits]} return
+    if {![info exists allcommits] || ![info exists arcnos($p)]} return
     lappend allids $id
     set allparents($id) [list $p]
     set allchildren($id) {}