patch 8.0.0753: no size reports to a job running in a terminal

Problem:    A job running in a terminal does not get notified of changes in
            the terminal size.
Solution:   Use ioctl() and SIGWINCH to report the terminal size.

src/os_unix.c

@@ -3918,6 +3918,44 @@ mch_get_shellsize(void)
     return OK;
 }
 
+#if defined(FEAT_TERMINAL) || defined(PROTO)
+/*
+ * Report the windows size "rows" and "cols" to tty "fd".
+ */
+    int
+mch_report_winsize(int fd, int rows, int cols)
+{
+# ifdef TIOCSWINSZ
+    struct winsize	ws;
+
+    ws.ws_col = cols;
+    ws.ws_row = rows;
+    ws.ws_xpixel = cols * 5;
+    ws.ws_ypixel = rows * 10;
+    if (ioctl(fd, TIOCSWINSZ, &ws) == 0)
+    {
+	ch_log(NULL, "ioctl(TIOCSWINSZ) success");
+	return OK;
+    }
+    ch_log(NULL, "ioctl(TIOCSWINSZ) failed");
+# else
+#  ifdef TIOCSSIZE
+    struct ttysize	ts;
+
+    ts.ts_cols = cols;
+    ts.ts_lines = rows;
+    if (ioctl(fd, TIOCSSIZE, &ws) == 0)
+    {
+	ch_log(NULL, "ioctl(TIOCSSIZE) success");
+	return OK;
+    }
+    ch_log(NULL, "ioctl(TIOCSSIZE) failed");
+#  endif
+# endif
+    return FAIL;
+}
+#endif
+
 /*
  * Try to set the window size to Rows and Columns.
  */
@@ -5473,6 +5511,10 @@ mch_stop_job(job_T *job, char_u *how)
 	sig = SIGINT;
     else if (STRCMP(how, "kill") == 0)
 	sig = SIGKILL;
+#ifdef SIGWINCH
+    else if (STRCMP(how, "winch") == 0)
+	sig = SIGWINCH;
+#endif
     else if (isdigit(*how))
 	sig = atoi((char *)how);
     else

src/proto/os_unix.pro

@@ -53,6 +53,7 @@ void mch_setmouse(int on);
 void check_mouse_termcode(void);
 int mch_screenmode(char_u *arg);
 int mch_get_shellsize(void);
+int mch_report_winsize(int fd, int rows, int cols);
 void mch_set_shellsize(void);
 void mch_new_shellsize(void);
 int mch_parse_cmd(char_u *cmd, int use_shcf, char ***argv, int *argc);

src/terminal.c

@@ -12,10 +12,11 @@
  *
  * There are three parts:
  * 1. Generic code for all systems.
+ *    Uses libvterm for the terminal emulator.
  * 2. The MS-Windows implementation.
- *    Uses a hidden console for the terminal emulator.
+ *    Uses winpty.
  * 3. The Unix-like implementation.
- *    Uses libvterm for the terminal emulator directly.
+ *    Uses pseudo-tty's (pty's).
  *
  * For each terminal one VTerm is constructed.  This uses libvterm.  A copy of
  * that library is in the libvterm directory.
@@ -32,8 +33,6 @@
  * while, if the terminal window is visible, the screen contents is drawn.
  *
  * TODO:
- * - When 'termsize' is set and dragging the separator the terminal gets messed
- *   up.
  * - set buffer options to be scratch, hidden, nomodifiable, etc.
  * - set buffer name to command, add (1) to avoid duplicates.
  * - Add a scrollback buffer (contains lines to scroll off the top).
@@ -605,9 +604,32 @@ term_update_window(win_T *wp)
      */
     if ((!term->tl_rows_fixed && term->tl_rows != wp->w_height)
 	    || (!term->tl_cols_fixed && term->tl_cols != wp->w_width))
-	vterm_set_size(vterm,
-		term->tl_rows_fixed ? term->tl_rows : wp->w_height,
-		term->tl_cols_fixed ? term->tl_cols : wp->w_width);
+    {
+	int rows = term->tl_rows_fixed ? term->tl_rows : wp->w_height;
+	int cols = term->tl_cols_fixed ? term->tl_cols : wp->w_width;
+
+	vterm_set_size(vterm, rows, cols);
+	ch_logn(term->tl_job->jv_channel, "Resizing terminal to %d lines",
+									 rows);
+
+#if defined(UNIX)
+	/* Use an ioctl() to report the new window size to the job. */
+	if (term->tl_job != NULL && term->tl_job->jv_channel != NULL)
+	{
+	    int fd = -1;
+	    int part;
+
+	    for (part = PART_OUT; part < PART_COUNT; ++part)
+	    {
+		fd = term->tl_job->jv_channel->ch_part[part].ch_fd;
+		if (isatty(fd))
+		    break;
+	    }
+	    if (part < PART_COUNT && mch_report_winsize(fd, rows, cols) == OK)
+		mch_stop_job(term->tl_job, (char_u *)"winch");
+	}
+#endif
+    }
 
     /* The cursor may have been moved when resizing. */
     vterm_state_get_cursorpos(state, &pos);

src/version.c

@@ -769,6 +769,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    753,
 /**/
     752,
 /**/