Fix changing options with gpgconf.

* src/engine-gpgconf.c (gpgconf_write): Connect a pipe to the child's
stderr, and wait for it to be closed as an indication that gpgconf has
exited.  Also improve error handling.

GnuPG-bug-id: 2881
Signed-off-by: Justus Winter <[email protected]>

1 files changed, 54 insertions, 12 deletions

diff --git a/src/engine-gpgconf.c b/src/engine-gpgconf.c
index 01a60eb1..3e463105 100644
--- a/src/engine-gpgconf.c
+++ b/src/engine-gpgconf.c
@@ -710,8 +710,11 @@ gpgconf_write (void *engine, const char *arg1, char *arg2, gpgme_data_t conf)
   int buflen = 0;
   char *argv[7];
   int argc = 0;
-  int rp[2];
-  struct spawn_fd_item_s cfd[] = { {-1, 0 /* STDIN_FILENO */}, {-1, -1} };
+  int rp[2] = { -1, -1 };
+  int errp[2] = { -1, -1 };
+  struct spawn_fd_item_s cfd[] = { {-1, 0 /* STDIN_FILENO */},
+                                   {-1, 2 /* STDERR_FILENO */, -1},
+                                   {-1, -1} };
   int status;
   int nwrite;
 
@@ -731,19 +734,31 @@ gpgconf_write (void *engine, const char *arg1, char *arg2, gpgme_data_t conf)
   assert (argc < DIM (argv));
 
   if (_gpgme_io_pipe (rp, 0) < 0)
-    return gpg_error_from_syserror ();
+    {
+      err = gpg_error_from_syserror ();
+      goto leave;
+    }
+
+  if (_gpgme_io_pipe (errp, 1) < 0)
+    {
+      err = gpg_error_from_syserror ();
+      goto leave;
+    }
 
   cfd[0].fd = rp[0];
+  cfd[1].fd = errp[1];
 
   status = _gpgme_io_spawn (gpgconf->file_name, argv,
                             IOSPAWN_FLAG_DETACHED, cfd, NULL, NULL, NULL);
   if (status < 0)
     {
-      _gpgme_io_close (rp[0]);
-      _gpgme_io_close (rp[1]);
-      return gpg_error_from_syserror ();
+      err = gpg_error_from_syserror ();
+      goto leave;
     }
 
+  rp[0] = -1;
+  errp[1] = -1;
+
   for (;;)
     {
       if (buflen == 0)
@@ -757,14 +772,29 @@ gpgconf_write (void *engine, const char *arg1, char *arg2, gpgme_data_t conf)
 	  if (buflen < 0)
 	    {
 	      err = gpg_error_from_syserror ();
-	      _gpgme_io_close (rp[1]);
-	      return err;
+              goto leave;
 	    }
 	  else if (buflen == 0)
 	    {
 	      /* All is written.  */
 	      _gpgme_io_close (rp[1]);
-	      return 0;
+              rp[1] = -1;
+
+              for (;;)
+                {
+                  do
+                    {
+                      buflen = _gpgme_io_read (errp[0], buf, BUFLEN);
+                    }
+                  while (buflen < 0 && errno == EAGAIN);
+
+                  if (buflen == 0)
+                    {
+                      err = 0;
+                      goto leave;
+                    }
+                  /* XXX: Do something useful with BUF.  */
+                }
 	    }
 	}
 
@@ -782,12 +812,24 @@ gpgconf_write (void *engine, const char *arg1, char *arg2, gpgme_data_t conf)
 	}
       else if (nwrite < 0)
 	{
-	  _gpgme_io_close (rp[1]);
-	  return gpg_error_from_syserror ();
+	  err = gpg_error_from_syserror ();
+          goto leave;
 	}
     }
 
-  return 0;
+  assert (! "reached");
+
+ leave:
+  if (rp[0] != -1)
+    _gpgme_io_close (rp[0]);
+  if (rp[1] != -1)
+  _gpgme_io_close (rp[1]);
+  if (errp[0] != -1)
+    _gpgme_io_close (errp[0]);
+  if (errp[1] != -1)
+  _gpgme_io_close (errp[1]);
+
+  return err;
 }