FreeTDS Development Group

["Lowden, James K" <LowdenJK AT bernstein.com>]

> > "James K. Lowden" <jklowden AT schemamania.org> wrote:
> > src/dblib/unittests/rpc is broken in RC6 and HEAD.  I think it might
> be
> > the test; I'm not sure if it's valid to fetch the parameter's name
> after
> > dbresults() returns no more results.  In any case, when we get to
> > 
> >     fprintf(stdout, "'%s' instead.\n", retname);
> > 
> > retname points to outer space.  
> 
> I really don't understand. I looked at your change and I don't
> understand what should be changed... Yesterday I tought that problem
was
> using mssql (I had only a Sybase server to test) but today I tested
with
> mssql2k (newer and former test version) and I don't notice any
> problem...

        while dbresults() {
                while dbnextrow() [
                }
                if dbnumrets() {
                        name =  dbretname()
                }
        }
        puts(name);

Question: what is the lifetime of the memory pointed to by the return
value of dbretname()?  Can it be expected to remain unfreed after
dbresults() returns NO_MORE_RESULTS?  I think the answer is no.  

I know the unit test segfaulted on fprintf() trying to derereference
retname.  I didn't check rcp.c to see whether the pointer had been
freed.  Depending on your machine, of course, dereferencing a freed
value might or might not cause a problem.  

If you think I'm misreading the docs, or you know that a vendor's
implementation (consistently) allows the above, then we ensure
dbretname()'s return buffer isn't freed until it's reused.  If it turns
out it's not being freed, then I guess I'll have to look into what's
happening on my box.  

BTW, I was confused for a bit, I think by libtool.  The unit test
executables have moved, and unless you've done a "make clean" lately,
you might be picking up the old ones:

$ file $(find build/src/dblib/ -name rpc) | cut -b-63
build/src/dblib//unittests/.libs/rpc: ELF 32-bit LSB executable
build/src/dblib//unittests/rpc:       ELF 32-bit LSB executable

$ ls -ghn $(find build/src/dblib/ -name rpc)
-rwxr-xr-x  1 100   33K Mar 25  2004
build/src/dblib//unittests/.libs/rpc
-rwxr-xr-x  1 100   45K Jan  5 13:38 build/src/dblib//unittests/rpc

It used to be that unittests/.libs/rpc was the binary and unittests/rpc
was a script that called the binary.  Nowadays the .lib directory isn't
even created.  

--jkl

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