svn rev #19992: branches/krb5-1-6/ src/windows/identity/ui/

[tlyu@MIT.EDU]

Commit By: tlyu
Log Message: 
ticket: 5678
version_fixed: 1.6.3

pull up r19857 from trunk

 r19857 at cathode-dark-space:  jaltman | 2007-08-24 10:33:09 -0400
 ticket: new
 subject: NIM: Cannot cancel timers which have inserted a WM_TIMER message into the queue
 component: windows
 
 The credentials view in Network Identity Manager displays several user
 interface elements that need to be updated periodically such as any
 fields that denote the time remaining for a credential or an identity,
 or an icon and coloring used to indicate the expiration state.  When
 the display rows are computed, the credentials view creates a set of
 timers that reference each row that times out when that row needs to
 be redrawn.
 
 Since the rows change when switching views or when the outline is
 recomputed, all the timers are canceled and re-scheduled.  However, a
 race conditions exists where the timer times-out before it is
 canceled, in which case a WM_TIMER message is placed in the
 credential window's message queue.  Windows does not support
 canceling a timer that has already fired and has been placed on the
 message queue.
 
 By the time the WM_TIMER message is received by the window, the rows
 of the display would have been recomputed and the row that the message
 references may not be what it intended to reference. A spurious
 WM_TIMER message is harmless when it refers to a row corresponding to
 a credential.  However, the existing code assumed that if a timer event
 is received that referred to an outline row, then that outline must be
 an expanded view of an identity, which is currently the only type of
 outline row that receives timers.  This assumption does not always
 hold in the case of a spurious WM_TIMER message and may lead to the
 code attempting to use the outline data as a handle to an identity.
 The patch fixes the problem by checking if the row is actually an
 expanded view of an identity and ignoring the message if it is not.
 
 




Changed Files:
_U  branches/krb5-1-6/
U   branches/krb5-1-6/src/windows/identity/ui/credwnd.c