Certain isc_buffer_*() functions might call memmove() with the second
argument (source) set to NULL and the third argument (length) set to 0.
While harmless, it triggers an ubsan warning:
runtime error: null pointer passed as argument 2, which is declared to never be null
Modify all memmove() call sites in lib/isc/include/isc/buffer.h and
lib/isc/buffer.c which may potentially use NULL as the second argument
(source) so that memmove() is only called if the third argument (length)
is non-zero.
compare_rdata() was meant to be used as a qsort() callback. Meanwhile,
dns_rdataslab_merge() calls compare_rdata() for a pair of dns_rdata_t
structures rather than a pair of struct xrdata structures, which is
harmless, but triggers an ubsan warning:
rdataslab.c:84:33: runtime error: member access within address <address> with insufficient space for an object of type 'const struct xrdata'
Use dns_rdata_compare() instead of compare_rdata() to prevent the
warning from being triggered.
Replace the outer for loop with a while loop to emphasize it keeps
processing the first element of diff->tuples, which changes on each
iteration due to tuples being removed from diff->tuples by
move_matching_tuples().
The ENSURE assertion at the end of dns_diff_appendminimal() is not
needed because it is placed right after code which resets *tuplep to
NULL if it is not NULL already.
The INSIST assertion in move_matching_tuples() checks the same pointer
again.
Extract the portion of the do-while loop responsible for finding the
next tuple with the same name and type into a separate function to
improve code clarity.
The do-while loop in dns__zone_updatesigs() is hard to follow due to
heavy nesting and the 'tuple' variable also being used in the outer for
loop. Add a comment to explain the purpose of the do-while loop.
Extract it into a separate function to decrease indentation and prevent
using 'tuple' in two different loops.
Add a new ATF test, sigs_test, containing everything required to start
defining test cases for dns__zone_updatesigs(). The framework is
written in a way which ensures that changes to zone database applied by
any dns__zone_updatesigs() invocation are preserved between subsequent
checks.
Rename find_zone_keys() to dns__zone_findkeys() and move it to
lib/dns/zone_p.h, so that it can be used in unit tests. Add a comment
describing the purpose of this function.
Rename update_sigs() to dns__zone_updatesigs() and move it to
lib/dns/zone_p.h, so that it can be unit tested. Add a comment
describing the purpose of this function.
Rename zonediff_t to dns__zonediff_t and move it to lib/dns/zone_p.h, so
that unit tests can be written for functions taking pointers to
structures of this type as arguments.
Add a new private header file, lib/dns/zone_p.h, which will hold type
definitions and function prototypes not meant to be exported by libdns,
but required by zone-related unit tests.
Implement dns_test_difffromchanges(), a function which enables preparing
a dns_diff_t structure from a mostly-textual representation of zone
database changes to be applied. This will improve readability of test
case definitions by allowing contents of a dns_diff_t structure, passed
e.g. to update_sigs(), to be represented in a human-friendly manner.
The dns_test_makezone() helper function always assigns the created zone
to some view, which is not always necessary and complicates cleanup of
non-managed zones as they are required not to be assigned to any view.
Rework dns_test_makezone() in order to make it easier to use in unit
tests operating on non-managed zones. Use dns_name_fromstring() instead
of dns_name_fromtext() to simplify code. Do not use the CHECK() macro
and add comments to make code flow simpler to follow. Use
dns_test_makeview() instead of dns_view_create().
Adjust existing unit tests using this function so that they still pass.
