Thread

1. Re: [HACKERS] TCL_ARRAYS code in libpgtcl is pretty seriously broken

   Tom Lane <tgl@sss.pgh.pa.us> — 1998-10-05T23:39:39Z

   Massimo Dal Zotto <dz@cs.unitn.it> writes:
   >> [ my gripes about TCL_ARRAYS code snipped ]
   
   > I wrote this code and used it for two years without any problem. All
   > the bugs you mentioned disappear if you use the proper string output
   > functions which C-like escapes (code in contrib/string-io).
   
   Well, not the bug involving overwriting libpq's PGresult storage.
   But still, this explains a good deal.
   
   I guess my gripe here is that the TCL_ARRAYS option is enabled *by
   default* in the Postgres distribution, but the code does not work
   properly unless one plugs in a contrib function in the backend
   (and if the connection between the two is documented anywhere, I sure
   didn't see it).  This is not a reasonable default setup.
   
   As a short-term fix I suggest that we just turn off TCL_ARRAYS in
   the distributed config.h.in --- does that sound reasonable to you?
   
   In the longer term, there needs to be some way of applying the
   TCL_ARRAYS conversion code only when your contrib stuff is being used.
   Backing the conversion code out of pg_result and making it a separate
   function might do, but that is a low-tech solution that puts the
   responsibility on the application programmer to combine the right bits
   of frontend and backend functionality.  Perhaps someone can think of a
   better way?
   
   Ultimately I would like the text I/O functions to be completely 8-bit
   clean and able to deal with arbitrary byte strings.  That is not
   something we can hope to shoehorn into 6.4, though.
   
   			regards, tom lane
   
   

2. Re: [HACKERS] TCL_ARRAYS code in libpgtcl is pretty seriously broken

   Massimo Dal Zotto <dz@cs.unitn.it> — 1998-10-11T12:04:47Z

   > 
   > Massimo Dal Zotto <dz@cs.unitn.it> writes:
   > >> [ my gripes about TCL_ARRAYS code snipped ]
   > 
   > > I wrote this code and used it for two years without any problem. All
   > > the bugs you mentioned disappear if you use the proper string output
   > > functions which C-like escapes (code in contrib/string-io).
   > 
   > Well, not the bug involving overwriting libpq's PGresult storage.
   > But still, this explains a good deal.
   
   I didn't realize it could be called more than once for the same tuple.
   We must allocate and free a new string for each value. I will write a patch.
   
   > I guess my gripe here is that the TCL_ARRAYS option is enabled *by
   > default* in the Postgres distribution, but the code does not work
   > properly unless one plugs in a contrib function in the backend
   > (and if the connection between the two is documented anywhere, I sure
   > didn't see it).  This is not a reasonable default setup.
   
   I submitted the two patches at the same time but one of them was put in the
   contribs.
   
   > As a short-term fix I suggest that we just turn off TCL_ARRAYS in
   > the distributed config.h.in --- does that sound reasonable to you?
   
   Given the situation I agree that TCL_ARRAYS should be disabled by default.
   
   > In the longer term, there needs to be some way of applying the
   > TCL_ARRAYS conversion code only when your contrib stuff is being used.
   > Backing the conversion code out of pg_result and making it a separate
   > function might do, but that is a low-tech solution that puts the
   > responsibility on the application programmer to combine the right bits
   > of frontend and backend functionality.  Perhaps someone can think of a
   > better way?
   > 
   > Ultimately I would like the text I/O functions to be completely 8-bit
   > clean and able to deal with arbitrary byte strings.  That is not
   > something we can hope to shoehorn into 6.4, though.
   
   I completely agree on the last thing. It is something I have been asking
   from a long time but apparently nobody cared bout it.
   
   -- 
   Massimo Dal Zotto
   
   +----------------------------------------------------------------------+
   |  Massimo Dal Zotto                email:  dz@cs.unitn.it             |
   |  Via Marconi, 141                 phone:  ++39-461-534251            |
   |  38057 Pergine Valsugana (TN)     www:  http://www.cs.unitn.it/~dz/  |
   |  Italy                            pgp:  finger dz@tango.cs.unitn.it  |
   +----------------------------------------------------------------------+