patch 7.4.1438

Problem:    Can't get buffer number of a channel.
Solution:   Add ch_getbufnr().

runtime/doc/channel.txt

@@ -561,11 +561,14 @@ TODO:						*job-term*
 
 When the IO mode is "buffer" and there is a callback, the text is appended to
 the buffer before invoking the callback.
-							*E915*
+
 The name of the buffer is compared the full name of existing buffers.  If
-there is a match that buffer is used.  Otherwise a new buffer is created,
-where 'buftype' is set to "nofile" and 'bufhidden' to "hide".  If you prefer
-other settings, create the buffer first and pass the buffer number.
+there is a match that buffer is used.  Otherwise a new buffer is created.
+Use an empty name to always create a new buffer.  |ch_getbufnr()| can then be
+used to get the buffer number.
+
+For a new buffer 'buftype' is set to "nofile" and 'bufhidden' to "hide".  If
+you prefer other settings, create the buffer first and pass the buffer number.
 
 When the buffer written to is displayed in a window and the cursor is in the
 first column of the last line, the cursor will be moved to the newly added

runtime/doc/eval.txt

@@ -1822,6 +1822,7 @@ ch_evalexpr( {channel}, {expr} [, {options}])
 				any	evaluate {expr} on JSON {channel}
 ch_evalraw( {channel}, {string} [, {options}])
 				any	evaluate {string} on raw {channel}
+ch_getbufnr( {channel}, {what})	Number	get buffer number for {channel}/{what}
 ch_getjob( {channel})		Job	get the Job of {channel}
 ch_log( {msg} [, {channel}])	none	write {msg} in the channel log file
 ch_logfile( {fname} [, {mode}])	none	start logging channel activity
@@ -2721,6 +2722,13 @@ ch_evalraw({channel}, {string} [, {options}])		*ch_evalraw()*
 
 		{only available when compiled with the |+channel| feature}
 
+ch_getbufnr({channel}, {what})				 *ch_getbufnr()*
+		Get the buffer number that {channel} is using for {what}.
+		{what} can be "err" for stderr, "out" for stdout or empty for
+		socket output.
+		Returns -1 when there is no buffer.
+		{only available when compiled with the |+channel| feature}
+
 ch_getjob({channel})						*ch_getjob()*
 		Get the Job associated with {channel}.
 		If there is no job calling |job_status()| on the returned Job

src/channel.c

@@ -787,12 +787,15 @@ channel_set_job(channel_T *channel, job_T *job)
     static buf_T *
 find_buffer(char_u *name)
 {
-    buf_T *buf = buflist_findname(name);
+    buf_T *buf = NULL;
     buf_T *save_curbuf = curbuf;
 
+    if (name != NULL && *name != NUL)
+	buf = buflist_findname(name);
     if (buf == NULL)
     {
-	buf = buflist_new(name, NULL, (linenr_T)0, BLN_LISTED);
+	buf = buflist_new(name == NULL ? (char_u *)"" : name,
+					       NULL, (linenr_T)0, BLN_LISTED);
 	buf_copy_options(buf, BCO_ENTER);
 #ifdef FEAT_QUICKFIX
 	clear_string_option(&buf->b_p_bt);
@@ -880,7 +883,7 @@ channel_set_options(channel_T *channel, jobopt_T *opt)
 	channel->ch_part[PART_OUT].ch_mode = MODE_NL;
 	channel->ch_part[PART_OUT].ch_buffer =
 				       find_buffer(opt->jo_io_name[PART_OUT]);
-	ch_logs(channel, "writing to buffer %s",
+	ch_logs(channel, "writing to buffer '%s'",
 		      (char *)channel->ch_part[PART_OUT].ch_buffer->b_ffname);
     }
 }
@@ -1357,7 +1360,14 @@ may_invoke_callback(channel_T *channel, int part)
 	callback = channel->ch_part[part].ch_callback;
     else
 	callback = channel->ch_callback;
+
     buffer = channel->ch_part[part].ch_buffer;
+    if (buffer != NULL && !buf_valid(buffer))
+    {
+	/* buffer was wiped out */
+	channel->ch_part[part].ch_buffer = NULL;
+	buffer = NULL;
+    }
 
     if (ch_mode == MODE_JSON || ch_mode == MODE_JS)
     {

src/eval.c

@@ -499,6 +499,7 @@ static void f_ceil(typval_T *argvars, typval_T *rettv);
 static void f_ch_close(typval_T *argvars, typval_T *rettv);
 static void f_ch_evalexpr(typval_T *argvars, typval_T *rettv);
 static void f_ch_evalraw(typval_T *argvars, typval_T *rettv);
+static void f_ch_getbufnr(typval_T *argvars, typval_T *rettv);
 # ifdef FEAT_JOB
 static void f_ch_getjob(typval_T *argvars, typval_T *rettv);
 # endif
@@ -8195,6 +8196,7 @@ static struct fst
     {"ch_close",	1, 1, f_ch_close},
     {"ch_evalexpr",	2, 3, f_ch_evalexpr},
     {"ch_evalraw",	2, 3, f_ch_evalraw},
+    {"ch_getbufnr",	2, 2, f_ch_getbufnr},
 # ifdef FEAT_JOB
     {"ch_getjob",	1, 1, f_ch_getjob},
 # endif
@@ -10227,13 +10229,6 @@ get_job_options(typval_T *tv, jobopt_T *opt, int supported)
 	return FAIL;
     }
 
-    for (part = PART_OUT; part <= PART_IN; ++part)
-	if (opt->jo_io[part] == JIO_BUFFER && opt->jo_io_name[part] == NULL)
-	{
-	    EMSG(_("E915: Missing name for buffer"));
-	    return FAIL;
-	}
-
     return OK;
 }
 #endif
@@ -10278,6 +10273,33 @@ f_ch_close(typval_T *argvars, typval_T *rettv UNUSED)
     }
 }
 
+/*
+ * "ch_getbufnr()" function
+ */
+    static void
+f_ch_getbufnr(typval_T *argvars, typval_T *rettv)
+{
+    channel_T *channel = get_channel_arg(&argvars[0]);
+
+    rettv->vval.v_number = -1;
+    if (channel != NULL)
+    {
+	char_u	*what = get_tv_string(&argvars[1]);
+	int	part;
+
+	if (STRCMP(what, "err") == 0)
+	    part = PART_ERR;
+	else if (STRCMP(what, "out") == 0)
+	    part = PART_OUT;
+	else if (STRCMP(what, "in") == 0)
+	    part = PART_IN;
+	else
+	    part = PART_SOCK;
+	if (channel->ch_part[part].ch_buffer != NULL)
+	    rettv->vval.v_number = channel->ch_part[part].ch_buffer->b_fnum;
+    }
+}
+
 # ifdef FEAT_JOB
 /*
  * "ch_getjob()" function

src/testdir/test_channel.vim

@@ -400,6 +400,32 @@ func Test_pipe_to_buffer()
   endtry
 endfunc
 
+func Test_pipe_to_nameless_buffer()
+  if !has('job')
+    return
+  endif
+  call ch_log('Test_pipe_to_nameless_buffer()')
+  let job = job_start(s:python . " test_channel_pipe.py",
+	\ {'out-io': 'buffer'})
+  call assert_equal("run", job_status(job))
+  try
+    let handle = job_getchannel(job)
+    call ch_sendraw(handle, "echo line one\n")
+    call ch_sendraw(handle, "echo line two\n")
+    exe ch_getbufnr(handle, "out") . 'sbuf'
+    for i in range(100)
+      sleep 10m
+      if line('$') >= 3
+	break
+      endif
+    endfor
+    call assert_equal(['Reading from channel output...', 'line one', 'line two'], getline(1, '$'))
+    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 */
+/**/
+    1438,
 /**/
     1437,
 /**/