estream: Fix assertion failure due to es_flush.

* src/estream.c (es_writen): Set writing flag even if no data was
written.
--

GnuPG-bug-id: 2371
Signed-off-by: Werner Koch <[email protected]>

gniibe tracked the problem down to a fully valid change in GnuPG
(gnupg commit 12af2630cf4d1a39179179925fac8f2cce7504ff).  He wrote:

This is the first instance for estream to do READ and WRITE
(in the history of the code > 10 years :-).  In the [gnupg] function
agent_write_private_key, the pattern is:

    es_fopen
    es_fread
    es_fseek
    es_fwrite

which should work well, but if results core dump by assertion failure
in the function es_flush of libgpg-error.

1 files changed, 1 insertions, 3 deletions

diff --git a/src/estream.c b/src/estream.c
index 2033b23..e382a29 100644
--- a/src/estream.c
+++ b/src/estream.c
@@ -2679,6 +2679,7 @@ es_writen (estream_t _GPGRT__RESTRICT stream,
               else
                 goto out;
             }
+          stream->flags.writing = 1;
         }
     }
 
@@ -2701,9 +2702,6 @@ es_writen (estream_t _GPGRT__RESTRICT stream,
 
   if (bytes_written)
     *bytes_written = data_written;
-  if (data_written)
-    if (!stream->flags.writing)
-      stream->flags.writing = 1;
 
   return err;
 }