patch 8.0.0592: if a job writes to a buffer screen is not updatedv8.0.0592

Problem:    If a job writes to a buffer and the user is typing a command, the
            screen isn't updated. When a message is displayed the changed
            buffer may cause it to be cleared. (Ramel Eshed)
Solution:   Update the screen and then the command line if the screen didn't
            scroll. Avoid inserting screen lines, as it clears any message.
            Update the status line when the buffer changed.

8 files changed, 81 insertions, 11 deletions

diff --git a/src/channel.c b/src/channel.c
index 4039b6b25d..ffee334b54 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -2404,7 +2404,7 @@ append_to_buffer(buf_T *buffer, char_u *msg, channel_T *channel, ch_part_T part)
 		curbuf = curwin->w_buffer;
 	    }
 	}
-	redraw_buf_later(buffer, VALID);
+	redraw_buf_and_status_later(buffer, VALID);
 	channel_need_redraw = TRUE;
     }
 
diff --git a/src/ex_getln.c b/src/ex_getln.c
index c42abe983f..c7a6d852df 100644
--- a/src/ex_getln.c
+++ b/src/ex_getln.c
@@ -3337,10 +3337,17 @@ cmdline_del(int from)
     void
 redrawcmdline(void)
 {
+    redrawcmdline_ex(TRUE);
+}
+
+    void
+redrawcmdline_ex(int do_compute_cmdrow)
+{
     if (cmd_silent)
 	return;
     need_wait_return = FALSE;
-    compute_cmdrow();
+    if (do_compute_cmdrow)
+	compute_cmdrow();
     redrawcmd();
     cursorcmd();
 }
diff --git a/src/globals.h b/src/globals.h
index 28b71ac851..1d67b0d7af 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -97,6 +97,7 @@ EXTERN int	cmdline_row;
 EXTERN int	redraw_cmdline INIT(= FALSE);	/* cmdline must be redrawn */
 EXTERN int	clear_cmdline INIT(= FALSE);	/* cmdline must be cleared */
 EXTERN int	mode_displayed INIT(= FALSE);	/* mode is being displayed */
+EXTERN int	no_win_do_lines_ins INIT(= FALSE); /* don't insert lines */
 #if defined(FEAT_CRYPT) || defined(FEAT_EVAL)
 EXTERN int	cmdline_star INIT(= FALSE);	/* cmdline is crypted */
 #endif
diff --git a/src/proto/ex_getln.pro b/src/proto/ex_getln.pro
index 58b635b9fd..6f82904235 100644
--- a/src/proto/ex_getln.pro
+++ b/src/proto/ex_getln.pro
@@ -19,6 +19,7 @@ char_u *save_cmdline_alloc(void);
 void restore_cmdline_alloc(char_u *p);
 void cmdline_paste_str(char_u *s, int literally);
 void redrawcmdline(void);
+void redrawcmdline_ex(int do_compute_cmdrow);
 void redrawcmd(void);
 void compute_cmdrow(void);
 void gotocmdline(int clr);
diff --git a/src/proto/screen.pro b/src/proto/screen.pro
index 5bc3fbaafe..d98e34fd97 100644
--- a/src/proto/screen.pro
+++ b/src/proto/screen.pro
@@ -5,11 +5,12 @@ void redraw_later_clear(void);
 void redraw_all_later(int type);
 void redraw_curbuf_later(int type);
 void redraw_buf_later(buf_T *buf, int type);
+void redraw_buf_and_status_later(buf_T *buf, int type);
 int redraw_asap(int type);
 void redraw_after_callback(void);
 void redrawWinline(linenr_T lnum, int invalid);
 void update_curbuf(int type);
-void update_screen(int type);
+void update_screen(int type_arg);
 int conceal_cursor_line(win_T *wp);
 void conceal_check_cursur_line(void);
 void update_single_line(win_T *wp, linenr_T lnum);
diff --git a/src/screen.c b/src/screen.c
index fbfded1a29..43490fb8f6 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -265,6 +265,21 @@ redraw_buf_later(buf_T *buf, int type)
     }
 }
 
+    void
+redraw_buf_and_status_later(buf_T *buf, int type)
+{
+    win_T	*wp;
+
+    FOR_ALL_WINDOWS(wp)
+    {
+	if (wp->w_buffer == buf)
+	{
+	    redraw_win_later(wp, type);
+	    wp->w_redr_status = TRUE;
+	}
+    }
+}
+
 /*
  * Redraw as soon as possible.  When the command line is not scrolled redraw
  * right away and restore what was on the command line.
@@ -421,10 +436,29 @@ redraw_after_callback(void)
     if (State == HITRETURN || State == ASKMORE)
 	; /* do nothing */
     else if (State & CMDLINE)
-	redrawcmdline();
+    {
+	/* Redrawing only works when the screen didn't scroll. */
+	if (msg_scrolled == 0)
+	{
+	    update_screen(0);
+	    compute_cmdrow();
+	}
+	else
+	{
+	    /* Redraw in the same position, so that the user can continue
+	     * editing the command. */
+	    compute_cmdrow();
+	    if (cmdline_row > msg_scrolled)
+		cmdline_row -= msg_scrolled;
+	    else
+		cmdline_row = 0;
+	}
+	redrawcmdline_ex(FALSE);
+    }
     else if (State & (NORMAL | INSERT))
     {
-	update_screen(0);
+	/* keep the command line if possible */
+	update_screen(VALID_NO_UPDATE);
 	setcursor();
     }
     cursor_on();
@@ -476,7 +510,7 @@ redrawWinline(
 }
 
 /*
- * update all windows that are editing the current buffer
+ * Update all windows that are editing the current buffer.
  */
     void
 update_curbuf(int type)
@@ -490,8 +524,9 @@ update_curbuf(int type)
  * of stuff from Filemem to ScreenLines[], and update curwin->w_botline.
  */
     void
-update_screen(int type)
+update_screen(int type_arg)
 {
+    int		type = type_arg;
     win_T	*wp;
     static int	did_intro = FALSE;
 #if defined(FEAT_SEARCH_EXTRA) || defined(FEAT_CLIPBOARD)
@@ -502,11 +537,18 @@ update_screen(int type)
     int		gui_cursor_col;
     int		gui_cursor_row;
 #endif
+    int		no_update = FALSE;
 
     /* Don't do anything if the screen structures are (not yet) valid. */
     if (!screen_valid(TRUE))
 	return;
 
+    if (type == VALID_NO_UPDATE)
+    {
+	no_update = TRUE;
+	type = 0;
+    }
+
     if (must_redraw)
     {
 	if (type < must_redraw)	    /* use maximal type */
@@ -539,6 +581,8 @@ update_screen(int type)
     ++display_tick;	    /* let syntax code know we're in a next round of
 			     * display updating */
 #endif
+    if (no_update)
+	++no_win_do_lines_ins;
 
     /*
      * if the screen was scrolled up when displaying a message, scroll it down
@@ -576,7 +620,8 @@ update_screen(int type)
 		    }
 		}
 	    }
-	    redraw_cmdline = TRUE;
+	    if (!no_update)
+		redraw_cmdline = TRUE;
 #ifdef FEAT_WINDOWS
 	    redraw_tabline = TRUE;
 #endif
@@ -748,6 +793,9 @@ update_screen(int type)
     if (clear_cmdline || redraw_cmdline)
 	showmode();
 
+    if (no_update)
+	--no_win_do_lines_ins;
+
     /* May put up an introductory message when not editing a file */
     if (!did_intro)
 	maybe_intro_message();
@@ -9475,6 +9523,11 @@ win_do_lines(
     if (!redrawing() || line_count <= 0)
 	return FAIL;
 
+    /* When inserting lines would result in loss of command output, just redraw
+     * the lines. */
+    if (no_win_do_lines_ins && !del)
+	return FAIL;
+
     /* only a few lines left: redraw is faster */
     if (mayclear && Rows - line_count < 5
 #ifdef FEAT_WINDOWS
@@ -9482,7 +9535,8 @@ win_do_lines(
 #endif
 	    )
     {
-	screenclear();	    /* will set wp->w_lines_valid to 0 */
+	if (!no_win_do_lines_ins)
+	    screenclear();	    /* will set wp->w_lines_valid to 0 */
 	return FAIL;
     }
 
@@ -9498,10 +9552,12 @@ win_do_lines(
     }
 
     /*
-     * when scrolling, the message on the command line should be cleared,
+     * When scrolling, the message on the command line should be cleared,
      * otherwise it will stay there forever.
+     * Don't do this when avoiding to insert lines.
      */
-    clear_cmdline = TRUE;
+    if (!no_win_do_lines_ins)
+	clear_cmdline = TRUE;
 
     /*
      * If the terminal can set a scroll region, use that.
diff --git a/src/version.c b/src/version.c
index 45f80ee544..fb0d9a56b5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    592,
+/**/
     591,
 /**/
     590,
diff --git a/src/vim.h b/src/vim.h
index 57866ef53e..cbe14e5356 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -630,6 +630,8 @@ extern int (*dyn_libintl_putenv)(const char *envstring);
  * flags for update_screen()
  * The higher the value, the higher the priority
  */
+#define VALID_NO_UPDATE		 5  /* no new changes, keep the command line if
+				       possible */
 #define VALID			10  /* buffer not changed, or changes marked
 				       with b_mod_* */
 #define INVERTED		20  /* redisplay inverted part that changed */