Merge branch 'obsd-master'

grid-view.c

@@ -67,6 +67,7 @@ grid_view_clear_history(struct grid *gd)
 		grid_collect_history(gd);
 		grid_scroll_history(gd);
 	}
+	gd->hscrolled = 0;
 }
 
 /* Clear area. */

grid.c

@@ -99,6 +99,7 @@ grid_create(u_int sx, u_int sy, u_int hlimit)
 
 	gd->flags = GRID_HISTORY;
 
+	gd->hscrolled = 0;
 	gd->hsize = 0;
 	gd->hlimit = hlimit;
 
@@ -170,6 +171,8 @@ grid_collect_history(struct grid *gd)
 
 	grid_move_lines(gd, 0, yy, gd->hsize + gd->sy - yy);
 	gd->hsize -= yy;
+	if (gd->hscrolled > gd->hsize)
+		gd->hscrolled = gd->hsize;
 }
 
 /*
@@ -186,6 +189,7 @@ grid_scroll_history(struct grid *gd)
 	    sizeof *gd->linedata);
 	memset(&gd->linedata[yy], 0, sizeof gd->linedata[yy]);
 
+	gd->hscrolled++;
 	gd->hsize++;
 }
 
@@ -196,7 +200,9 @@ grid_clear_history(struct grid *gd)
 	grid_clear_lines(gd, 0, gd->hsize);
 	grid_move_lines(gd, 0, gd->hsize, gd->sy);
 
+	gd->hscrolled = 0;
 	gd->hsize = 0;
+
 	gd->linedata = xreallocarray(gd->linedata, gd->sy,
 	    sizeof *gd->linedata);
 }
@@ -231,6 +237,7 @@ grid_scroll_history_region(struct grid *gd, u_int upper, u_int lower)
 	memset(gl_lower, 0, sizeof *gl_lower);
 
 	/* Move the history offset down over the line. */
+	gd->hscrolled++;
 	gd->hsize++;
 }
 
@@ -914,6 +921,10 @@ grid_reflow(struct grid *dst, struct grid *src, u_int new_x)
 			grid_reflow_join(dst, &py, src_gl, new_x);
 		}
 		previous_wrapped = (src_gl->flags & GRID_LINE_WRAPPED);
+
+		/* This is where we started scrolling. */
+		if (line == sy + src->hsize - src->hscrolled - 1)
+			dst->hscrolled = 0;
 	}
 
 	grid_destroy(src);

screen-write.c

@@ -1016,7 +1016,7 @@ screen_write_clearhistory(struct screen_write_ctx *ctx)
 	struct grid	*gd = s->grid;
 
 	grid_move_lines(gd, 0, gd->hsize, gd->sy);
-	gd->hsize = 0;
+	gd->hscrolled = gd->hsize = 0;
 }
 
 /* Write cell data. */

screen.c

@@ -177,8 +177,9 @@ screen_resize_y(struct screen *s, u_int sy)
 	 * If the height is decreasing, delete lines from the bottom until
 	 * hitting the cursor, then push lines from the top into the history.
 	 *
-	 * When increasing, pull as many lines as possible from the history to
-	 * the top, then fill the remaining with blanks at the bottom.
+	 * When increasing, pull as many lines as possible from scrolled
+	 * history (not explicitly cleared from view) to the top, then fill the
+	 * remaining with blanks at the bottom.
 	 */
 
 	/* Size decreasing. */
@@ -200,9 +201,10 @@ screen_resize_y(struct screen *s, u_int sy)
 		 * lines from the top.
 		 */
 		available = s->cy;
-		if (gd->flags & GRID_HISTORY)
+		if (gd->flags & GRID_HISTORY) {
+			gd->hscrolled += needed;
 			gd->hsize += needed;
-		else if (needed > 0 && available > 0) {
+		} else if (needed > 0 && available > 0) {
 			if (available > needed)
 				available = needed;
 			grid_view_delete_lines(gd, 0, available);
@@ -219,13 +221,14 @@ screen_resize_y(struct screen *s, u_int sy)
 		needed = sy - oldy;
 
 		/*
-		 * Try to pull as much as possible out of the history, if is
+		 * Try to pull as much as possible out of scrolled history, if is
 		 * is enabled.
 		 */
-		available = gd->hsize;
+		available = gd->hscrolled;
 		if (gd->flags & GRID_HISTORY && available > 0) {
 			if (available > needed)
 				available = needed;
+			gd->hscrolled -= available;
 			gd->hsize -= available;
 			s->cy += available;
 		} else

tmux.h

@@ -693,6 +693,7 @@ struct grid {
 	u_int			 sx;
 	u_int			 sy;
 
+	u_int			 hscrolled;
 	u_int			 hsize;
 	u_int			 hlimit;