The main goal is to allow configuration information to be temporarily
overridden by a separate config file. That will require further
changes not in this commit.
The performance impact is unclear, and will depend on the balance
between number of queries and number of distinct metadata items read
on the first call to n_d_get_config.
As diagnosed by Olivier Taïbi in
id:20201027100916.emry3k2wujod4xnl@galois.lan, if an exception is
thrown while the initialization is happening (e.g. if the function is
called on a closed database), then the destructor is (sometimes)
invoked on an uninitialized Xapian object.
Solve the problem by moving the setting of the destructor until after
the placement new successfully completes. It is conceivable this might
cause a memory leak, but that seems preferable to crashing, and in any
case, there seems to be nothing better to be done if the
initialization is failing things are in an undefined state by
definition.
static_cast is a bit tricky to understand and error prone, so add a
second pointer to (potentially the same) Xapian database object that
we know has the right subclass.
The documentation for notmuch_config_list_key warns that that the
returned value will be destroyed by the next call to
notmuch_config_list_key, but it neglected to mention that calling
notmuch_config_list_value would also destroy it (by calling
notmuch_config_list_key). This is surprising, and caused a use after
free bug in _setup_user_query_fields (first noticed by an OpenBSD
porter, so kudos to the OpenBSD malloc implementation). This change
fixes that use-after-free bug.
C99 stdbool turned 18 this year. There really is no reason to use our
own, except in the library interface for backward
compatibility. Convert the lib internally to stdbool.
Many of the external links found in the notmuch source can be resolved
using https instead of http. This changeset addresses as many as i
could find, without touching the e-mail corpus or expected outputs
found in tests.
Since xapian provides the ability to restrict the iterator to a given
prefix, we expose this ability to the user. Otherwise we mimic the other
iterator interfances in notmuch (e.g. tags.c).
This is a thin wrapper around the Xapian metadata API. The job of this
layer is to keep the config key value pairs from colliding with other
metadata by transparently prefixing the keys, along with the usual glue
to provide a C interface.
The split of _get_config into two functions is to allow returning of the
return value with different memory ownership semantics.
