patch 7.4.2109

Problem:    Setting 'display' to "lastline" is a drastic change, while
            omitting it results in lots of "@" lines.
Solution:   Add "truncate" to show "@@@" for a truncated line.

Author: brammool

runtime/doc/options.txt

@@ -2623,11 +2623,17 @@ A jump table for the options with a short description can be found at |Q_op|.
 	Change the way text is displayed.  This is comma separated list of
 	flags:
 	lastline	When included, as much as possible of the last line
-			in a window will be displayed.  When not included, a
-			last line that doesn't fit is replaced with "@" lines.
+			in a window will be displayed.  "@@@" is put in the
+			last columns of the last screen line to indicate the
+			rest of the line is not displayed.
+	truncate	Like "lastline", but "@@@" is displayed in the first
+			column of the last screen line.  Overrules "lastline".
 	uhex		Show unprintable characters hexadecimal as <xx>
 			instead of using ^C and ~C.
 
+	When neither "lastline" or "truncate" is included, a last line that
+	doesn't fit is replaced with "@" lines.
+
 						*'eadirection'* *'ead'*
 'eadirection' 'ead'	string	(default "both")
 			global

src/option.h

@@ -454,10 +454,11 @@ EXTERN char_u	*p_dir;		/* 'directory' */
 EXTERN char_u	*p_dy;		/* 'display' */
 EXTERN unsigned	dy_flags;
 #ifdef IN_OPTION_C
-static char *(p_dy_values[]) = {"lastline", "uhex", NULL};
+static char *(p_dy_values[]) = {"lastline", "truncate", "uhex", NULL};
 #endif
 #define DY_LASTLINE		0x001
-#define DY_UHEX			0x002
+#define DY_TRUNCATE		0x002
+#define DY_UHEX			0x004
 EXTERN int	p_ed;		/* 'edcompatible' */
 #ifdef FEAT_WINDOWS
 EXTERN char_u	*p_ead;		/* 'eadirection' */

src/screen.c

@@ -2018,7 +2018,7 @@ win_update(win_T *wp)
 		    && wp->w_lines[idx].wl_valid
 		    && wp->w_lines[idx].wl_lnum == lnum
 		    && lnum > wp->w_topline
-		    && !(dy_flags & DY_LASTLINE)
+		    && !(dy_flags & (DY_LASTLINE | DY_TRUNCATE))
 		    && srow + wp->w_lines[idx].wl_size > wp->w_height
 #ifdef FEAT_DIFF
 		    && diff_check_fill(wp, lnum) == 0
@@ -2139,6 +2139,21 @@ win_update(win_T *wp)
 	    wp->w_filler_rows = wp->w_height - srow;
 	}
 #endif
+	else if (dy_flags & DY_TRUNCATE)	/* 'display' has "truncate" */
+	{
+	    int scr_row = W_WINROW(wp) + wp->w_height - 1;
+
+	    /*
+	     * Last line isn't finished: Display "@@@" in the last screen line.
+	     */
+	    screen_puts_len((char_u *)"@@", 2, scr_row, W_WINCOL(wp),
+							      hl_attr(HLF_AT));
+	    screen_fill(scr_row, scr_row + 1,
+		    (int)W_WINCOL(wp) + 2, (int)W_ENDCOL(wp),
+		    '@', ' ', hl_attr(HLF_AT));
+	    set_empty_rows(wp, srow);
+	    wp->w_botline = lnum;
+	}
 	else if (dy_flags & DY_LASTLINE)	/* 'display' has "lastline" */
 	{
 	    /*

src/version.c

@@ -758,6 +758,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2109,
 /**/
     2108,
 /**/