core: Allow setting the base directory when creating an archive

* src/engine-gpg.c (gpg_encrypt, gpg_encrypt_sign, gpg_sign): Pass
file name set in data with --directory option to gpgtar.

* tests/run-encrypt.c (show_usage): New option --directory.
(main): Parse new option. Set file name of input data to option value.
* tests/run-sign.c (show_usage): New option --directory.
(main): Parse new option. Set file name of input data to option value.
--

GnuPG-bug-id: 6342

doc/gpgme.texi

@@ -2199,6 +2199,11 @@ associated with the data object.  The file name will be stored in the
 output when encrypting or signing the data and will be returned to the
 user when decrypting or verifying the output data.
 
+If a signed or encrypted archive is created, then the file name will be
+interpreted as the base directory for the relative paths of the files and
+directories to put into the archive.  This corresponds to the --directory
+option of gpgtar.
+
 The function returns the error code @code{GPG_ERR_INV_VALUE} if
 @var{dh} is not a valid pointer and @code{GPG_ERR_ENOMEM} if not
 enough memory is available.
@@ -6260,7 +6265,8 @@ If signature mode @code(GPGME_SIG_MODE_ARCHIVE) is requested, then a
 signed archive is created from the files and directories given as
 NUL-separated list in the data object @var{plain} and returned in the
 data object @var{sig}.  The paths of the files and directories have to
-be given as paths relative to the current working directory.
+be given as paths relative to the current working directory or relative
+to the base directory set with @code{gpgme_data_set_file_name}.
 
 After the operation completed successfully, the result can be
 retrieved with @code{gpgme_op_sign_result}.
@@ -6437,7 +6443,8 @@ If the flag @code(GPGME_ENCRYPT_ARCHIVE) is set, then an encrypted
 archive is created from the files and directories given as NUL-separated
 list in the data object @var{plain} and returned in the data object
 @var{cipher}.  The paths of the files and directories have to
-be given as paths relative to the current working directory.
+be given as paths relative to the current working directory or relative
+to the base directory set with @code{gpgme_data_set_file_name}.
 
 @var{recp} must be a @code{NULL}-terminated array of keys.  The user
 must keep references for all keys during the whole duration of the

src/engine-gpg.c

@@ -2369,13 +2369,15 @@ gpg_encrypt (void *engine, gpgme_key_t recp[], const char *recpstring,
     err = add_arg (gpg, "-");
   if (!err)
     err = add_data (gpg, ciph, 1, 1);
-  if (gpgme_data_get_file_name (plain))
-    {
-      if (!err)
-	err = add_gpg_arg_with_value (gpg, "--set-filename=", gpgme_data_get_file_name (plain), 0);
-    }
   if (gpg->flags.use_gpgtar)
     {
+      const char *file_name = gpgme_data_get_file_name (plain);
+      if (!err && file_name)
+        {
+          err = add_arg (gpg, "--directory");
+          if (!err)
+            err = add_arg (gpg, file_name);
+        }
       if (!err)
 	err = add_arg (gpg, "--files-from");
       if (!err)
@@ -2390,6 +2392,9 @@ gpg_encrypt (void *engine, gpgme_key_t recp[], const char *recpstring,
     }
   else
     {
+      const char *file_name = gpgme_data_get_file_name (plain);
+      if (!err && file_name)
+	err = add_gpg_arg_with_value (gpg, "--set-filename=", file_name, 0);
       if (!err)
         err = add_input_size_hint (gpg, plain);
       if (!err)
@@ -2476,13 +2481,15 @@ gpg_encrypt_sign (void *engine, gpgme_key_t recp[],
     err = add_arg (gpg, "-");
   if (!err)
     err = add_data (gpg, ciph, 1, 1);
-  if (gpgme_data_get_file_name (plain))
-    {
-      if (!err)
-	err = add_gpg_arg_with_value (gpg, "--set-filename=", gpgme_data_get_file_name (plain), 0);
-    }
   if (gpg->flags.use_gpgtar)
     {
+      const char *file_name = gpgme_data_get_file_name (plain);
+      if (!err && file_name)
+        {
+          err = add_arg (gpg, "--directory");
+          if (!err)
+            err = add_arg (gpg, file_name);
+        }
       if (!err)
 	err = add_arg (gpg, "--files-from");
       if (!err)
@@ -2497,6 +2504,9 @@ gpg_encrypt_sign (void *engine, gpgme_key_t recp[],
     }
   else
     {
+      const char *file_name = gpgme_data_get_file_name (plain);
+      if (!err && file_name)
+	err = add_gpg_arg_with_value (gpg, "--set-filename=", file_name, 0);
       if (!err)
         err = add_input_size_hint (gpg, plain);
       if (!err)
@@ -3584,15 +3594,16 @@ gpg_sign (void *engine, gpgme_data_t in, gpgme_data_t out,
   if (!err)
     err = append_args_from_sig_notations (gpg, ctx, NOTATION_FLAG_SIG);
 
-  if (gpgme_data_get_file_name (in))
-    {
-      if (!err)
-	err = add_gpg_arg_with_value (gpg, "--set-filename=", gpgme_data_get_file_name (in), 0);
-    }
-
   /* Tell the gpg object about the data.  */
   if (gpg->flags.use_gpgtar)
     {
+      const char *file_name = gpgme_data_get_file_name (in);
+      if (!err && file_name)
+        {
+          err = add_arg (gpg, "--directory");
+          if (!err)
+            err = add_arg (gpg, file_name);
+        }
       if (!err)
 	err = add_arg (gpg, "--files-from");
       if (!err)
@@ -3607,6 +3618,9 @@ gpg_sign (void *engine, gpgme_data_t in, gpgme_data_t out,
     }
   else
     {
+      const char *file_name = gpgme_data_get_file_name (in);
+      if (!err && file_name)
+	err = add_gpg_arg_with_value (gpg, "--set-filename=", file_name, 0);
       if (!err)
         err = add_input_size_hint (gpg, in);
       if (!err)

tests/run-encrypt.c

@@ -134,6 +134,7 @@ show_usage (int ex)
          "  --wrap             assume input is valid OpenPGP message\n"
          "  --symmetric        encrypt symmetric (OpenPGP only)\n"
          "  --archive          encrypt given file or directory into an archive\n"
+         "  --directory DIR    switch to directory DIR before encrypting into an archive\n"
          "  --diagnostics      print diagnostics\n"
          , stderr);
   exit (ex);
@@ -157,6 +158,7 @@ main (int argc, char **argv)
   gpgme_key_t keys[10+1];
   int keycount = 0;
   char *keystring = NULL;
+  const char *directory = NULL;
   int i;
   gpgme_encrypt_flags_t flags = GPGME_ENCRYPT_ALWAYS_TRUST;
   gpgme_off_t offset;
@@ -266,6 +268,14 @@ main (int argc, char **argv)
           flags |= GPGME_ENCRYPT_ARCHIVE;
           argc--; argv++;
         }
+      else if (!strcmp (*argv, "--directory"))
+        {
+          argc--; argv++;
+          if (!argc)
+            show_usage (1);
+          directory = *argv;
+          argc--; argv++;
+        }
       else if (!strcmp (*argv, "--diagnostics"))
         {
           diagnostics = 1;
@@ -319,6 +329,12 @@ main (int argc, char **argv)
     {
       const char *path = *argv;
       err = gpgme_data_new_from_mem (&in, path, strlen (path), 0);
+      fail_if_err (err);
+      if (directory)
+        {
+          err = gpgme_data_set_file_name (in, directory);
+          fail_if_err (err);
+        }
     }
   else
     {

tests/run-sign.c

@@ -88,6 +88,7 @@ show_usage (int ex)
          "  --include-key-block  use this option with gpg\n"
          "  --clear          create a clear text signature\n"
          "  --archive        create a signed archive with the given file or directory\n"
+         "  --directory DIR  switch to directory DIR before creating the archive\n"
          "  --diagnostics    print diagnostics\n"
          , stderr);
   exit (ex);
@@ -101,6 +102,7 @@ main (int argc, char **argv)
   gpgme_error_t err;
   gpgme_ctx_t ctx;
   const char *key_string = NULL;
+  const char *directory = NULL;
   gpgme_protocol_t protocol = GPGME_PROTOCOL_OpenPGP;
   gpgme_sig_mode_t sigmode = GPGME_SIG_MODE_NORMAL;
   gpgme_data_t in, out;
@@ -186,6 +188,14 @@ main (int argc, char **argv)
           sigmode = GPGME_SIG_MODE_ARCHIVE;
           argc--; argv++;
         }
+      else if (!strcmp (*argv, "--directory"))
+        {
+          argc--; argv++;
+          if (!argc)
+            show_usage (1);
+          directory = *argv;
+          argc--; argv++;
+        }
       else if (!strcmp (*argv, "--diagnostics"))
         {
           diagnostics = 1;
@@ -253,6 +263,12 @@ main (int argc, char **argv)
     {
       const char *path = *argv;
       err = gpgme_data_new_from_mem (&in, path, strlen (path), 0);
+      fail_if_err (err);
+      if (directory)
+        {
+          err = gpgme_data_set_file_name (in, directory);
+          fail_if_err (err);
+        }
     }
   else
     {