git-1.5.5.5-alt1
tcl-8.5.2-alt1
tk-8.5.2-alt1
openssh-5.0p1-alt3
xorg-server-1.4.2-alt10.M41.1

How to reproduce:

$ ssh 0 -l mort -X
mort@0's password: 
Last login: Tue Jun  9 10:15:30 2009 from localhost.localdomain
[mort@localhost ~]$  cd tmp/tests/
[mort@localhost tests]$  mkdir test-gitk
[mort@localhost tests]$ cd test-gitk/
[mort@localhost test-gitk]$  git init
Initialized empty Git repository in .git/
[mort@localhost test-gitk]$ echo a > a
[mort@localhost test-gitk]$ git add a
[mort@localhost test-gitk]$ git commit -m 'Initial.'
Created initial commit 24562b8: Initial.
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 a
[mort@localhost test-gitk]$ gitk
X Error of failed request:  BadWindow (invalid Window parameter)
  Major opcode of failed request:  7 (X_ReparentWindow)
  Resource id in failed request:  0x74
  Serial number of failed request:  3462
  Current serial number in output stream:  3464
[mort@localhost test-gitk]$ 


In the gitk, I right-clicked on the commit, and went on to add a tag; in the tag dialog I added the tag name, and clicked on the button "Create".

Result: the tag was created, but gitk crashed. (It seems that such a crash happens every time a window belonging to gitk is closed. The same error messages appear when the main window is closed.)

Expected: gitk doesn't crash when some of its windows is closed.