[plt-dev] FYI: Intermittently, editors pack/unpack to length 0 string ?

I'm having another intermittent problem that may be related to the  
recent changes to editors.

I'm using the handin engine to accept assignments, and I've now twice  
gotten into a state where the handin server reports failure because it  
claims that the submission is of zero length.  I added some diagnostic  
code the first time, and discovered that sending "get-text" (sp?) to  
the text% that is the result of .. okay, let me just write this in  
scheme:

   (let*-values ([(defs dc) (unpack-submission bytes)]
                 [(text) (send defs get-text)])
   (string-length text))

This evaluates to zero.  Closing and restarting the client-side  
DrScheme makes the problem go away.

I realize that a valuable diagnostic result here would be the length  
(and content) of the value 'bytes', and if this happens again, I'll  
try to capture it.

In the meantime, all I can tell you is that packing and unpacking the  
definitions window using the Handin server periodically results in an  
empty string.

One final piece of information, hopefully irrelevant: I'm using  
drocaml, here, so the definitions window in question contains an  
editor that's being operated on by drocaml code.  I imagine that it  
shouldn't be possible for drocaml to get the editor into a "bad  
state", but I can't be sure.

This may belong in the FYI bin.

John Clements

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