[ldns-users] ldns_buffer2str asserting after ldns_buffer_copy

[Karel Slany]

Hello again,

I'm writing some scripts for automated checking of pyLDNS basic
functionality. I have encountered strange behaviour of the
ldns_buffer_copy and ldns_buffer2str function.

ldns_buffer: ./buffer.c:82: ldns_buffer_reserve: Assertion
`!buffer->_fixed' failed.

I am not sure whether this is a bug or I am missing something. But I
haven't found any clues in the documentation telling me why this
shouldn't work.

I've rewritten the code to C, in order to make it more understandable:

#include <stdio.h>
#include <ldns/ldns.h>

int main(void)
{
	ldns_buffer *b1, *b2;
	char *str;

	b1 = ldns_buffer_new(1024);
	b2 = ldns_buffer_new(10);

	ldns_buffer_printf(b1, "%s", "abc");
	ldns_buffer_printf(b2, "%s", "def");

	str = ldns_buffer2str(b1);
	fprintf(stdout, "b1: %s\n", str);
	LDNS_FREE(str);

	str = ldns_buffer2str(b2);
	fprintf(stdout, "b2: %s\n", str);
	LDNS_FREE(str);

	ldns_buffer_copy(b1, b2);

	str = ldns_buffer2str(b1); /* Asserts here. */
	fprintf(stdout, "b1: %s\n", str);
	LDNS_FREE(str);

	str = ldns_buffer2str(b2);
	fprintf(stdout, "b2: %s\n", str);
	LDNS_FREE(str);

	ldns_buffer_free(b1);
	ldns_buffer_free(b2);
}

The comment shows the position, where the code is asserting.

I've tested ldns 1.6.13 and also the latest SVN (revision 3707), both
behave the same.

K.