TRAPEXIT doesn't get executed

[Matt Armstrong <matt@xxxxxxxxxxxxxx>]

I'm trying to find the right idiom to make sure some cleanup code gets
executed no matter how the script exits.

When I run this script:
  
---------------------------------------------------------
#!/usr/bin/zsh
  
set -x
  
function TRAPEXIT {
    print "executed TRAPEXIT"
}
sleep 10
---------------------------------------------------------
  
And hit Ctrl-C while "sleep 10" is executing, the TRAPEXIT isn't
executed.  But when I run this script:
  
---------------------------------------------------------
#!/usr/bin/zsh
  
set -x

function TRAPEXIT {
    print "executed TRAPEXIT"
}
function TRAPINT {
    print "executed TRAPINT"
}
sleep 10
---------------------------------------------------------

And hit Ctrl-C, both TRAPINT and TRAPEXIT get executed.  Is this
explained anywhere?  The behavior is the same under 3.0 and 3.1, so I
imagine this has been covered before.

-- 
matt