patch 7.4.1465

Problem:    Coverity reported possible use of NULL pointer when using buffer
            output with JSON mode.
Solution:   Make it actually possible to use JSON mode with a buffer.
            Re-encode the JSON to append it to the buffer.

src/channel.c

@@ -926,7 +926,8 @@ channel_set_options(channel_T *channel, jobopt_T *opt)
 
     if ((opt->jo_set & JO_OUT_IO) && opt->jo_io[PART_OUT] == JIO_BUFFER)
     {
-	/* writing output to a buffer. Force mode to NL. */
+	/* writing output to a buffer. Default mode is NL. */
+	if (!(opt->jo_set & JO_OUT_MODE))
 	    channel->ch_part[PART_OUT].ch_mode = MODE_NL;
 	channel->ch_part[PART_OUT].ch_buffer =
 				       find_buffer(opt->jo_io_name[PART_OUT]);
@@ -1560,6 +1561,11 @@ may_invoke_callback(channel_T *channel, int part)
 	    u_sync(TRUE);
 	    u_save(lnum, lnum + 1);
 
+	    if (msg == NULL)
+		/* JSON or JS mode: re-encode the message. */
+		msg = json_encode(listtv, ch_mode);
+	    if (msg != NULL)
+	    {
 		ml_append(lnum, msg, 0, FALSE);
 		appended_lines_mark(lnum, 1L);
 		curbuf = save_curbuf;
@@ -1588,6 +1594,7 @@ may_invoke_callback(channel_T *channel, int part)
 		    channel_need_redraw = TRUE;
 		}
 	    }
+	}
 	if (callback != NULL)
 	{
 	    /* invoke the channel callback */

src/testdir/test_channel.vim

@@ -426,6 +426,32 @@ func Test_pipe_to_nameless_buffer()
   endtry
 endfunc
 
+func Test_pipe_to_buffer_json()
+  if !has('job')
+    return
+  endif
+  call ch_log('Test_pipe_to_buffer_json()')
+  let job = job_start(s:python . " test_channel_pipe.py",
+	\ {'out-io': 'buffer', 'out-mode': 'json'})
+  call assert_equal("run", job_status(job))
+  try
+    let handle = job_getchannel(job)
+    call ch_sendraw(handle, "echo [0, \"hello\"]\n")
+    call ch_sendraw(handle, "echo [-2, 12.34]\n")
+    exe ch_getbufnr(handle, "out") . 'sbuf'
+    for i in range(100)
+      sleep 10m
+      if line('$') >= 3
+	break
+      endif
+    endfor
+    call assert_equal(['Reading from channel output...', '[0,"hello"]', '[-2,12.34]'], getline(1, '$'))
+    bwipe!
+  finally
+    call job_stop(job)
+  endtry
+endfunc
+
 """"""""""
 
 let s:unletResponse = ''

src/version.c

@@ -743,6 +743,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1465,
 /**/
     1464,
 /**/