[Guy Harris <gharris@xxxxxxxxx>]

Pierre JUHEN wrote:

> Obvisously, the stack has been corrupted in between.

Are you inferring that because capture_opts is on the stack?

If so, are you certain it's on the stack, rather than in a register?

Optimizing compilers can make debuggers lie - it might be that 
cf_close() is trashing the stack, but it might also be that capture_opts 
is passed on the stack (from the pointers, I assume you've compiled this 
in x86-64 mode rather than x86 mode; as x86-64 has, as I remember, 16 
more-or-less general-purpose registers, C compilers might be more likely 
to pass parameters in registers, but perhaps the x86-64 ABI is modeled 
after the x86 ABI and has parameters passed on the stack), but was 
loaded into a register and that the debugger symbol table has it in the 
register in question - but that the register in question isn't saved and 
restored by the caller or callee, and is thus trashed, so that the 
generated code following the cf_close() call will fetch it from the stack.

You might want to try doing

	fprintf(stderr, "capture_opts %p\n", capture_opts);

before and after the cf_close() call, to see whether its value is 
getting trashed or if the debugger is just getting confused by the 
optimized code.