Problem

__prepared_discover_btree_has_prepare in src/prepared_discover/prepared_discover_walk.c (lines 11-37) duplicates checkpoint metadata config parsing that already exists in RTS. The function even has a comment calling this out:

This configuration parsing is copied out of the rollback to stable implementation

The duplicated logic iterates the checkpoint config sub-entries and checks the prepare flag:

WT_RET(__wt_config_getones(session, config, "checkpoint", &cval));
__wt_config_subinit(session, &ckptconf, &cval);
for (; __wt_config_next(&ckptconf, &key, &cval) == 0;) {
    ret = __wt_config_subgets(session, &cval, "prepare", &value);
    if (ret == 0) {
        if (value.val)
            *has_prepp = true;
    }
    WT_RET_NOTFOUND_OK(ret);
}

The same loop lives inside __wti_rts_btree_walk_btree_apply in src/rollback_to_stable/rts_btree_walk.c (lines 331-370), which extracts the same prepare flag along with newest_start_durable_ts, newest_stop_durable_ts, newest_txn, addr, and write_gen.

Proposed Fix

Extract a shared helper — e.g. _wt_meta_checkpoint_parse_info — in src/meta/meta_ckpt.c that iterates checkpoint config sub-entries and populates an output struct with all fields both callers need. Both prepared_discover_btree_has_prepare and _wti_rts_btree_walk_btree_apply replace their inline loops with a call to this helper.

Files Affected

• src/prepared_discover/prepared_discover_walk.c — __prepared_discover_btree_has_prepare
• src/rollback_to_stable/rts_btree_walk.c — __wti_rts_btree_walk_btree_apply
• src/meta/meta_ckpt.c — new shared helper (or a new meta_ckpt_utils.c)