core: Deprecate the non-working trustlist functions.

* src/gpgme.h.in: Clarify that the trustlist function should not be
used.
* src/engine.c (_gpgme_engine_op_trustlist): Always return an error.
* src/engine-backend.h (struct engine_ops): Remove trustlist member.
* src/engine-gpg.c (gpg_trustlist): Remove.
(struct engine_ops): Remove that member.  Also in all other engines.
* tests/gpg/t-trustlist.c: Remove.
* lang/python/tests/t-trustlist.py: Remove.
--

This never worked in reality because the required feature has been
removed from GnuPG version 1.3.2 soon after introduction of this
feature in gpgme - 17 years ago.  It was anyway marked as
experimental.  We keep the API and ABI, though.

GnuPG-bug-id: 4834
Signed-off-by: Werner Koch <[email protected]>

10 files changed, 13 insertions, 82 deletions

diff --git a/src/engine-assuan.c b/src/engine-assuan.c
index 497397db..a40328f7 100644
--- a/src/engine-assuan.c
+++ b/src/engine-assuan.c
@@ -826,7 +826,6 @@ struct engine_ops _gpgme_engine_ops_assuan =
     NULL,               /* keysign */
     NULL,               /* tofu_policy */
     NULL,               /* sign */
-    NULL,		/* trustlist */
     NULL,               /* verify */
     NULL,               /* getauditlog */
     llass_transact,     /* opassuan_transact */
diff --git a/src/engine-backend.h b/src/engine-backend.h
index 4f33da1c..c8bfad96 100644
--- a/src/engine-backend.h
+++ b/src/engine-backend.h
@@ -115,7 +115,6 @@ struct engine_ops
 			 gpgme_sig_mode_t mode, int use_armor,
 			 int use_textmode, int include_certs,
 			 gpgme_ctx_t ctx /* FIXME */);
-  gpgme_error_t (*trustlist) (void *engine, const char *pattern);
   gpgme_error_t (*verify) (void *engine, gpgme_data_t sig,
 			   gpgme_data_t signed_text, gpgme_data_t plaintext,
                            gpgme_ctx_t ctx);
diff --git a/src/engine-g13.c b/src/engine-g13.c
index 19dd8f47..45f6c94b 100644
--- a/src/engine-g13.c
+++ b/src/engine-g13.c
@@ -806,7 +806,6 @@ struct engine_ops _gpgme_engine_ops_g13 =
     NULL,               /* keysign */
     NULL,               /* tofu_policy */
     NULL,               /* sign */
-    NULL,		/* trustlist */
     NULL,               /* verify */
     NULL,               /* getauditlog */
     g13_transact,
diff --git a/src/engine-gpg.c b/src/engine-gpg.c
index c343e80e..9362e297 100644
--- a/src/engine-gpg.c
+++ b/src/engine-gpg.c
@@ -3303,29 +3303,6 @@ gpg_sign (void *engine, gpgme_data_t in, gpgme_data_t out,
 }
 
 static gpgme_error_t
-gpg_trustlist (void *engine, const char *pattern)
-{
-  engine_gpg_t gpg = engine;
-  gpgme_error_t err;
-
-  err = add_arg (gpg, "--with-colons");
-  if (!err)
-    err = add_arg (gpg, "--list-trust-path");
-
-  /* Tell the gpg object about the data.  */
-  if (!err)
-    err = add_arg (gpg, "--");
-  if (!err)
-    err = add_arg (gpg, pattern);
-
-  if (!err)
-    err = start (gpg);
-
-  return err;
-}
-
-
-static gpgme_error_t
 gpg_verify (void *engine, gpgme_data_t sig, gpgme_data_t signed_text,
 	    gpgme_data_t plaintext, gpgme_ctx_t ctx)
 {
@@ -3475,7 +3452,6 @@ struct engine_ops _gpgme_engine_ops_gpg =
     gpg_keysign,
     gpg_tofu_policy,    /* tofu_policy */
     gpg_sign,
-    gpg_trustlist,
     gpg_verify,
     gpg_getauditlog,
     NULL,               /* opassuan_transact */
diff --git a/src/engine-gpgconf.c b/src/engine-gpgconf.c
index 303ba640..d4465e97 100644
--- a/src/engine-gpgconf.c
+++ b/src/engine-gpgconf.c
@@ -1304,7 +1304,6 @@ struct engine_ops _gpgme_engine_ops_gpgconf =
     NULL,               /* keysign */
     NULL,               /* tofu_policy */
     NULL,		/* sign */
-    NULL,		/* trustlist */
     NULL,		/* verify */
     NULL,		/* getauditlog */
     NULL,               /* opassuan_transact */
diff --git a/src/engine-gpgsm.c b/src/engine-gpgsm.c
index ae5d8ef1..671b3857 100644
--- a/src/engine-gpgsm.c
+++ b/src/engine-gpgsm.c
@@ -2324,7 +2324,6 @@ struct engine_ops _gpgme_engine_ops_gpgsm =
     NULL,               /* keysign */
     NULL,               /* tofu_policy */
     gpgsm_sign,
-    NULL,		/* trustlist */
     gpgsm_verify,
     gpgsm_getauditlog,
     NULL,               /* opassuan_transact */
diff --git a/src/engine-spawn.c b/src/engine-spawn.c
index 296d7f25..0eeaeb1f 100644
--- a/src/engine-spawn.c
+++ b/src/engine-spawn.c
@@ -466,7 +466,6 @@ struct engine_ops _gpgme_engine_ops_spawn =
     NULL,               /* keysign */
     NULL,               /* tofu_policy */
     NULL,		/* sign */
-    NULL,		/* trustlist */
     NULL,		/* verify */
     NULL,		/* getauditlog */
     NULL,               /* opassuan_transact */
diff --git a/src/engine-uiserver.c b/src/engine-uiserver.c
index cb8e155d..c908ad7f 100644
--- a/src/engine-uiserver.c
+++ b/src/engine-uiserver.c
@@ -1437,7 +1437,6 @@ struct engine_ops _gpgme_engine_ops_uiserver =
     NULL,               /* keysign */
     NULL,               /* tofu_policy */
     uiserver_sign,
-    NULL,		/* trustlist */
     uiserver_verify,
     NULL,		/* getauditlog */
     NULL,               /* opassuan_transact */
diff --git a/src/engine.c b/src/engine.c
index 05979c15..ded2f4d1 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -917,13 +917,12 @@ _gpgme_engine_op_sign (engine_t engine, gpgme_data_t in, gpgme_data_t out,
 gpgme_error_t
 _gpgme_engine_op_trustlist (engine_t engine, const char *pattern)
 {
+  (void)pattern;
+
   if (!engine)
     return gpg_error (GPG_ERR_INV_VALUE);
 
-  if (!engine->ops->trustlist)
-    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);
-
-  return (*engine->ops->trustlist) (engine->engine, pattern);
+  return gpg_error (GPG_ERR_NOT_IMPLEMENTED);
 }
 
 
diff --git a/src/gpgme.h.in b/src/gpgme.h.in
index 4efa325d..2decc551 100644
--- a/src/gpgme.h.in
+++ b/src/gpgme.h.in
@@ -313,7 +313,7 @@ typedef enum
 gpgme_sig_mode_t;
 
 
-/* The available validities for a trust item or key.  */
+/* The available validities for a key.  */
 typedef enum
   {
     GPGME_VALIDITY_UNKNOWN   = 0,
@@ -1054,7 +1054,7 @@ typedef enum
     GPGME_EVENT_START,
     GPGME_EVENT_DONE,
     GPGME_EVENT_NEXT_KEY,
-    GPGME_EVENT_NEXT_TRUSTITEM
+    GPGME_EVENT_NEXT_TRUSTITEM  /* NOT USED.  */
   }
 gpgme_event_io_t;
 
@@ -2002,63 +2002,32 @@ gpgme_error_t gpgme_op_passwd (gpgme_ctx_t ctx, gpgme_key_t key,
 
 
 /*
- * Trust items and operations.
+ * Trust items and operations.  DO NOT USE.
+ * Note: This does not work because the experimental support in the
+ * GnuPG engine has been removed a very long time; for API and ABI
+ * compatibilty we keep the functions but let them return an error.
+ * See https://dev.gnupg.org/T4834
  */
-
-/* An object to hold data of a trust item.
- * This structure shall be considered read-only and an application
- * must not allocate such a structure on its own.  */
 struct _gpgme_trust_item
 {
-  /* Internal to GPGME, do not use.  */
   unsigned int _refs;
-
-  /* The key ID to which the trust item belongs.  */
   char *keyid;
-
-  /* Internal to GPGME, do not use.  */
   char _keyid[16 + 1];
-
-  /* The type of the trust item, 1 refers to a key, 2 to a user ID.  */
   int type;
-
-  /* The trust level.  */
   int level;
-
-  /* The owner trust if TYPE is 1.  */
   char *owner_trust;
-
-  /* Internal to GPGME, do not use.  */
   char _owner_trust[2];
-
-  /* The calculated validity.  */
   char *validity;
-
-  /* Internal to GPGME, do not use.  */
   char _validity[2];
-
-  /* The user name if TYPE is 2.  */
   char *name;
 };
 typedef struct _gpgme_trust_item *gpgme_trust_item_t;
-
-/* Start a trustlist operation within CTX, searching for trust items
-   which match PATTERN.  */
 gpgme_error_t gpgme_op_trustlist_start (gpgme_ctx_t ctx,
 					const char *pattern, int max_level);
-
-/* Return the next trust item from the trustlist in R_ITEM.  */
 gpgme_error_t gpgme_op_trustlist_next (gpgme_ctx_t ctx,
 				       gpgme_trust_item_t *r_item);
-
-/* Terminate a pending trustlist operation within CTX.  */
 gpgme_error_t gpgme_op_trustlist_end (gpgme_ctx_t ctx);
-
-/* Acquire a reference to ITEM.  */
 void gpgme_trust_item_ref (gpgme_trust_item_t item);
-
-/* Release a reference to ITEM.  If this was the last one the trust
- * item is destroyed.  */
 void gpgme_trust_item_unref (gpgme_trust_item_t item);
 
 
@@ -2740,22 +2709,16 @@ unsigned long gpgme_key_sig_get_ulong_attr (gpgme_key_t key, int uid_idx,
 gpgme_error_t gpgme_op_import_ext (gpgme_ctx_t ctx, gpgme_data_t keydata,
 				   int *nr) _GPGME_DEPRECATED(0,4);
 
-/* Release the trust item ITEM.  Deprecated, use
- * gpgme_trust_item_unref.  */
+/* DO NOT USE.  */
 void gpgme_trust_item_release (gpgme_trust_item_t item) _GPGME_DEPRECATED(0,4);
 
-/* Return the value of the attribute WHAT of ITEM, which has to be
- * representable by a string.  Deprecated, use trust item structure
- * directly.  */
+/* DO NOT USE.  */
 const char *gpgme_trust_item_get_string_attr (gpgme_trust_item_t item,
 					      _gpgme_attr_t what,
 					      const void *reserved, int idx)
      _GPGME_DEPRECATED(0,4);
 
-/* Return the value of the attribute WHAT of KEY, which has to be
- * representable by an integer.  IDX specifies a running index if the
- * attribute appears more than once in the key.  Deprecated, use trust
- * item structure directly.  */
+/* DO NOT USE.  */
 int gpgme_trust_item_get_int_attr (gpgme_trust_item_t item, _gpgme_attr_t what,
 				   const void *reserved, int idx)
      _GPGME_DEPRECATED(0,4);