New decrypt flags GPGME_DECRYPT_LISTONLY.HEADmaster

* src/gpgme.h.in (GPGME_DECRYPT_LISTONLY): New.
* src/decrypt.c (op_data_t): Add member list_only.
(_gpgme_decrypt_status_handler): Do not return NO_DATA in list_only
mode.
(_gpgme_op_decrypt_init_result): Add arg flags and set the list_only
flag.
(_gpgme_decrypt_start): Pss flags to the init function.
* src/decrypt-verify.c (decrypt_verify_start): Ditto.
* src/engine-gpg.c (gpg_decrypt): Add --list-only if flag is set.

* tests/run-decrypt.c (main): Add option --list-only.

1 files changed, 9 insertions, 4 deletions

diff --git a/src/decrypt.c b/src/decrypt.c
index e5d2f7c7..c6030eef 100644
--- a/src/decrypt.c
+++ b/src/decrypt.c
@@ -44,7 +44,10 @@ typedef struct
 
   int okay;
 
-  /* A flag telling that the a decryption failed and two optional error
+  /* Indicates that list only mode is active.  */
+  int list_only;
+
+  /* A flag telling that the decryption failed and two optional error
    * codes to further specify the failure for public key decryption and
    * symmetric decryption.  */
   int failed;
@@ -419,7 +422,7 @@ _gpgme_decrypt_status_handler (void *priv, gpgme_status_code_t code,
           /* Generic decryption failed error code.  */
           return gpg_error (GPG_ERR_DECRYPT_FAILED);
         }
-      else if (!opd->okay)
+      else if (!opd->okay && !opd->list_only)
         {
           /* No data was found.  */
           return gpg_error (GPG_ERR_NO_DATA);
@@ -540,7 +543,8 @@ decrypt_status_handler (void *priv, gpgme_status_code_t code, char *args)
 
 
 gpgme_error_t
-_gpgme_op_decrypt_init_result (gpgme_ctx_t ctx, gpgme_data_t plaintext)
+_gpgme_op_decrypt_init_result (gpgme_ctx_t ctx, gpgme_data_t plaintext,
+                               gpgme_decrypt_flags_t flags)
 {
   gpgme_error_t err;
   void *hook;
@@ -552,6 +556,7 @@ _gpgme_op_decrypt_init_result (gpgme_ctx_t ctx, gpgme_data_t plaintext)
   if (err)
     return err;
 
+  opd->list_only = !!(flags & GPGME_DECRYPT_LISTONLY);
   opd->last_recipient_p = &opd->result.recipients;
   opd->plaintext_dserial = _gpgme_data_get_dserial (plaintext);
   return 0;
@@ -571,7 +576,7 @@ _gpgme_decrypt_start (gpgme_ctx_t ctx, int synchronous,
   if (err)
     return err;
 
-  err = _gpgme_op_decrypt_init_result (ctx, plain);
+  err = _gpgme_op_decrypt_init_result (ctx, plain, flags);
   if (err)
     return err;