gpgsm: Terminate key listing on output write error.

* sm/keylist.c (list_internal_keys): Detect write errors to the output
stream.

* sm/server.c (any_failure_printed): New var.
(gpgsm_status2): Handle new var.  Move statusfp init to ...
(gpgsm_init_statusfp): new function.
(gpgsm_exit_failure_status): New.
* sm/gpgsm.c (main): Explicit statusfp init.
(gpgsm_exit): Print failure status on error.
--
Test by using

  gpgsm -k >/dev/full
  gpgsm -k --wit-colons >/dev/full

and also by redirecting to a file on a small partition.

GnuPG-bug-id: 6185

sm/gpgsm.c

@@ -1803,6 +1803,10 @@ main ( int argc, char **argv)
       gnupg_inhibit_set_foregound_window (1);
     }
 
+  /* Better make sure that we have a statusfp so that a failure status
+   * in gpgsm_exit can work even w/o any preeding status messages. */
+  gpgsm_init_statusfp (&ctrl);
+
   /* Add default keybox. */
   if (!nrings && default_keyring && !opt.use_keyboxd)
     {
@@ -2356,6 +2360,12 @@ gpgsm_exit (int rc)
   else if (opt.assert_signer_list && !assert_signer_true)
     rc = 1;
 
+  /* If we had an error but not printed an error message, do it now.
+   * Note that the function will never print a second failure status
+   * line. */
+  if (rc)
+    gpgsm_exit_failure_status ();
+
   gcry_control (GCRYCTL_UPDATE_RANDOM_SEED_FILE);
   if (opt.debug & DBG_MEMSTAT_VALUE)
     {

sm/gpgsm.h

@@ -355,12 +355,14 @@ int  gpgsm_parse_validation_model (const char *model);
 
 /*-- server.c --*/
 void gpgsm_server (certlist_t default_recplist);
+void gpgsm_init_statusfp (ctrl_t ctrl);
 gpg_error_t gpgsm_status (ctrl_t ctrl, int no, const char *text);
 gpg_error_t gpgsm_status2 (ctrl_t ctrl, int no, ...) GPGRT_ATTR_SENTINEL(0);
 gpg_error_t gpgsm_status_with_err_code (ctrl_t ctrl, int no, const char *text,
                                         gpg_err_code_t ec);
 gpg_error_t gpgsm_status_with_error (ctrl_t ctrl, int no, const char *text,
                                      gpg_error_t err);
+void gpgsm_exit_failure_status (void);
 gpg_error_t gpgsm_progress_cb (ctrl_t ctrl, uint64_t current, uint64_t total);
 gpg_error_t gpgsm_proxy_pinentry_notify (ctrl_t ctrl,
                                          const unsigned char *line);

sm/keylist.c

@@ -1663,6 +1663,7 @@ list_internal_keys (ctrl_t ctrl, strlist_t names, estream_t fp,
 
       resname = keydb_get_resource_name (hd);
 
+      es_clearerr (fp);
       if (lastresname != resname )
         {
           int i;
@@ -1716,6 +1717,20 @@ list_internal_keys (ctrl_t ctrl, strlist_t names, estream_t fp,
       ksba_cert_release (lastcert);
       lastcert = cert;
       cert = NULL;
+
+      if (es_ferror (fp))
+        rc = gpg_error_from_syserror ();
+
+      /* For faster key listings we flush the output after each cert
+       * only if we list secret keys.  */
+      if ((mode & 2) && es_fflush (fp) && !rc)
+        rc = gpg_error_from_syserror ();
+
+      if (rc)
+        {
+          log_error (_("error writing to output: %s\n"), gpg_strerror (rc));
+          goto leave;
+        }
     }
   if (gpg_err_code (rc) == GPG_ERR_NOT_FOUND)
     rc = 0;

sm/server.c

@@ -37,6 +37,11 @@
 #define set_error(e,t) assuan_set_error (ctx, gpg_error (e), (t))
 
 
+/* Used to track whether we printed any FAILURE status in non-server
+ * mode.  */
+static int any_failure_printed;
+
+
 /* The filepointer for status message used in non-server mode */
 static FILE *statusfp;
 
@@ -1515,6 +1520,24 @@ gpgsm_server (certlist_t default_recplist)
 }
 
 
+void
+gpgsm_init_statusfp (ctrl_t ctrl)
+{
+  if (statusfp || ctrl->status_fd == -1)
+    return;
+
+  if (ctrl->status_fd == 1)
+    statusfp = stdout;
+  else if (ctrl->status_fd == 2)
+    statusfp = stderr;
+  else
+    statusfp = fdopen (ctrl->status_fd, "w");
+
+  if (!statusfp)
+    log_fatal ("can't open fd %d for status output: %s\n",
+               ctrl->status_fd, strerror(errno));
+}
+
 
 gpg_error_t
 gpgsm_status2 (ctrl_t ctrl, int no, ...)
@@ -1527,23 +1550,11 @@ gpgsm_status2 (ctrl_t ctrl, int no, ...)
 
   if (ctrl->no_server && ctrl->status_fd == -1)
     ; /* No status wanted. */
+  else if (ctrl->no_server && no == STATUS_FAILURE && any_failure_printed)
+    ; /* Don't emit FAILURE a second time.  */
   else if (ctrl->no_server)
     {
-      if (!statusfp)
-        {
-          if (ctrl->status_fd == 1)
-            statusfp = stdout;
-          else if (ctrl->status_fd == 2)
-            statusfp = stderr;
-          else
-            statusfp = fdopen (ctrl->status_fd, "w");
-
-          if (!statusfp)
-            {
-              log_fatal ("can't open fd %d for status output: %s\n",
-                         ctrl->status_fd, strerror(errno));
-            }
-        }
+      gpgsm_init_statusfp (ctrl);
 
       fputs ("[GNUPG:] ", statusfp);
       fputs (get_status_string (no), statusfp);
@@ -1562,6 +1573,10 @@ gpgsm_status2 (ctrl_t ctrl, int no, ...)
             }
         }
       putc ('\n', statusfp);
+
+      if (no == STATUS_FAILURE)
+        any_failure_printed = 1;
+
       if (ferror (statusfp))
         err = gpg_error_from_syserror ();
       else
@@ -1614,6 +1629,23 @@ gpgsm_status_with_error (ctrl_t ctrl, int no, const char *text,
 }
 
 
+/* Function to print a FAILURE status line on exit.  */
+void
+gpgsm_exit_failure_status (void)
+{
+  /* stderr is used as a last but possible wrong resort if no status
+   * has yet been printed. */
+  FILE *fp = statusfp? statusfp : stderr;
+
+  if (any_failure_printed)
+    return;
+
+  fputs ("[GNUPG:] ", fp);
+  fputs (get_status_string (STATUS_FAILURE), fp);
+  fputs (" gpgsm-exit 50331649\n", fp);
+}
+
+
 /* This callback is used to emit progress status lines.  */
 gpg_error_t
 gpgsm_progress_cb (ctrl_t ctrl, uint64_t current, uint64_t total)