diff --git a/gpgme/ChangeLog b/gpgme/ChangeLog
index 02bb5d65..039b197e 100644
--- a/gpgme/ChangeLog
+++ b/gpgme/ChangeLog
@@ -1,3 +1,13 @@
+2004-09-23  Marcus Brinkmann  <marcus@g10code.de>
+
+	* data-stream.c (stream_seek): Call ftello and return the current
+	offset.
+	* data.h (struct gpgme_data): Change type of data.mem.offset to
+	off_t.
+	* data.c (gpgme_data_seek): Check dh->cbs->seek callback, not read
+	callback.  If SEEK_CUR, adjust the offset by the pending buffer
+	size.  Clear pending buffer on success.
+
 2004-09-14  Marcus Brinkmann  <marcus@g10code.de>
 
 	* gpgme.m4: Add copyright notice.
diff --git a/gpgme/data-stream.c b/gpgme/data-stream.c
index c28f5ff2..3abecaaf 100644
--- a/gpgme/data-stream.c
+++ b/gpgme/data-stream.c
@@ -50,12 +50,19 @@ stream_write (gpgme_data_t dh, const void *buffer, size_t size)
 static off_t
 stream_seek (gpgme_data_t dh, off_t offset, int whence)
 {
+  int err;
+
 #ifdef HAVE_FSEEKO
-  return fseeko (dh->data.stream, offset, whence);
+  err = fseeko (dh->data.stream, offset, whence);
 #else
   /* FIXME: Check for overflow, or at least bail at compilation.  */
-  return fseek (dh->data.stream, offset, whence);
+  err = fseek (dh->data.stream, offset, whence);
 #endif
+
+  if (err)
+    return -1;
+
+  return ftello (dh->data.stream);
 }
 
 
diff --git a/gpgme/data.c b/gpgme/data.c
index 80a3fb4b..aba1986b 100644
--- a/gpgme/data.c
+++ b/gpgme/data.c
@@ -112,12 +112,22 @@ gpgme_data_seek (gpgme_data_t dh, off_t offset, int whence)
       errno = EINVAL;
       return -1;
     }
-  if (!dh->cbs->read)
+  if (!dh->cbs->seek)
     {
       errno = EOPNOTSUPP;
       return -1;
     }
-  return (*dh->cbs->seek) (dh, offset, whence);
+
+  /* For relative movement, we must take into account the actual
+     position of the read counter.  */
+  if (whence == SEEK_CUR)
+    offset -= dh->pending_len;
+
+  offset = (*dh->cbs->seek) (dh, offset, whence);
+  if (offset >= 0)
+    dh->pending_len = 0;
+
+  return offset;
 }
 
 
diff --git a/gpgme/data.h b/gpgme/data.h
index 57815ef3..51d89aa8 100644
--- a/gpgme/data.h
+++ b/gpgme/data.h
@@ -99,7 +99,7 @@ struct gpgme_data
       /* Allocated size of BUFFER.  */
       size_t size;
       size_t length;
-      size_t offset;
+      off_t offset;
     } mem;
 
     /* For gpgme_data_new_from_read_cb.  */