Add per-ctx custom engine options.bjk/custom-engine-options

* src/gpgme.h.in (gpgme_ctx_set_engine_options): New prototype.
(gpgme_ctx_get_engine_options): Ditto.
* src/engine-backend.h (engine_ops): Add set_options and get_options.
* src/engine.c (gpgme_ctx_set_engine_options): New.
(gpgme_ctx_get_engine_options): Ditto.
* src/engine-gpg.c (gpg_set_options): New.
(gpg_get_options): Ditto.
* src/op-support.c (_gpgme_op_reset): Keep custom options.
* src/engine-gpg.c (_gpgme_engine_ops_gpg): Adjust for new members.
* src/engine-assuan.c (_gpgme_engine_ops_assuan): Ditto.
* src/engine-g13.c (_gpgme_engine_ops_g13): Ditto.
* src/engine-gpgconf.c (_gpgme_engine_ops_gpgconf): Ditto.
* src/engine-gpgsm.c (_gpgme_engine_ops_gpgsm): Ditto.
* src/engine-spawn.c (_gpgme_engine_ops_spawn): Ditto.
* src/engine-uiserver.c (_gpgme_engine_ops_uiserver): Ditto.
* src/gpgme.def: Export new symbols.
* src/libgpgme.vers: Ditto.
* doc/gpgme.texi: Document these new functions.

--
Not all of gpg2's features are exposed to libgpgme and adding these
functions makes it possible to do things like specify an --s2k-count,
etc.

1 files changed, 25 insertions, 0 deletions

diff --git a/doc/gpgme.texi b/doc/gpgme.texi
index 45c359d0..b3aa369f 100644
--- a/doc/gpgme.texi
+++ b/doc/gpgme.texi
@@ -187,6 +187,7 @@ Context Attributes
 
 * Protocol Selection::            Selecting the protocol used by a context.
 * Crypto Engine::                 Configuring the crypto engine.
+* Custom Engine Options::         Adding command line options to an engine.
 * ASCII Armor::                   Requesting @acronym{ASCII} armored output.
 * Text Mode::                     Choosing canonical text mode.
 * Included Certificates::         Including a number of certificates.
@@ -2283,6 +2284,7 @@ started.  In fact, these references are accessed through the
 @menu
 * Protocol Selection::            Selecting the protocol used by a context.
 * Crypto Engine::                 Configuring the crypto engine.
+* Custom Engine Options::         Adding command line options to an engine.
 * ASCII Armor::                   Requesting @acronym{ASCII} armored output.
 * Text Mode::                     Choosing canonical text mode.
 * Included Certificates::         Including a number of certificates.
@@ -2362,6 +2364,29 @@ successful, or an eror code on failure.
 @end deftypefun
 
 
+@node Custom Engine Options
+@subsection Custom Engine Options
+@cindex context, configuring engine
+@cindex engine, configuration per context
+
+Since not all features of all engines may be exposed by @acronym{GPGME},
+additional command line arguments may be needed to allow the wanted
+functionality.
+
+@deftypefun gpgme_error_t gpgme_ctx_set_engine_options (@w{gpgme_ctx_t @var{ctx}}, @w{const char *@var{options}})
+The function @code{gpgme_ctx_set_engine_options} sets command line options for
+the configured engine in context @var{ctx} to @var{options}. The options are
+passed upon each op call and may be reset by setting @var{options} to
+@code{NULL}. This function returns @code{0} on success or an error on failure.
+@end deftypefun
+
+@deftypefun gpgme_error_t gpgme_ctx_get_engine_options (@w{gpgme_ctx_t @var{ctx}}, @w{char ** @var{result}})
+The function @code{gpgme_ctx_get_engine_options} returns the previously set
+engine options in @var{result}.  This function returns @code{0} on success or
+an error on failure.
+@end deftypefun
+
+
 @c FIXME: Unfortunately, using @acronym here breaks texi2dvi.
 @node ASCII Armor
 @subsection @acronym{ASCII} Armor