gitk: Fix bug caused by missing commitlisted elements

This bug was reported by Yann Dirson, and results in an 'Error:
expected boolean value but got ""' dialog when scrolling to the bottom
of the graph under some circumstances.  The issue is that git-rev-list
isn't outputting all the boundary commits when it is asked for commits
affecting only certain files.  We already cope with that by adding the
missing boundary commits in addextraid, but there we weren't adding a
0 to the end of the commitlisted list when we added the extra id to
the end of the displayorder list.

This fixes it by appending 0 to commitlisted in addextraid, thus keeping
commitlisted and displayorder in sync.

Signed-off-by: Paul Mackerras <paulus@samba.org>

gitk

@@ -1116,11 +1116,12 @@ proc layoutrows {row endrow last} {
 
 proc addextraid {id row} {
     global displayorder commitrow commitinfo
-    global commitidx
+    global commitidx commitlisted
     global parentlist childlist children
 
     incr commitidx
     lappend displayorder $id
+    lappend commitlisted 0
     lappend parentlist {}
     set commitrow($id) $row
     readcommit $id
@@ -1500,7 +1501,7 @@ proc drawcmittext {id row col rmx} {
 proc drawcmitrow {row} {
     global displayorder rowidlist
     global idrowranges idrangedrawn iddrawn
-    global commitinfo commitlisted parentlist numcommits
+    global commitinfo parentlist numcommits
 
     if {$row >= $numcommits} return
     foreach id [lindex $rowidlist $row] {