commit 23a895e

Fix scrolling to highlight on buffers with unread messages.

Thanks to kucha on #senpai for finding this issue.

 1@@ -588,17 +588,16 @@ func (bs *BufferList) SetRead(netID, title string, timestamp time.Time) {
 2 
 3 func (bs *BufferList) UpdateRead() (netID, title string, timestamp time.Time) {
 4 	b := bs.cur()
 5-	var line *Line
 6-	y := 0
 7-	for i := len(b.lines) - 1; 0 <= i; i-- {
 8-		line = &b.lines[i]
 9+	var l *Line
10+	bs.forEachLine(b, func(line *Line, y int) bool {
11+		l = line
12 		if y >= b.scrollAmt && line.Readable {
13-			break
14+			return true
15 		}
16-		y += len(line.NewLines(bs.ui.vx, bs.textWidth)) + 1
17-	}
18-	if line != nil && line.At.After(b.read) {
19-		b.read = line.At
20+		return false
21+	})
22+	if l != nil && l.At.After(b.read) {
23+		b.read = l.At
24 		return b.netID, b.title, b.read
25 	}
26 	return "", "", time.Time{}
27@@ -637,29 +636,27 @@ func (bs *BufferList) ScrollDown(n int) {
28 func (bs *BufferList) ScrollUpHighlight() bool {
29 	b := bs.cur()
30 	ymin := b.scrollAmt + bs.tlHeight
31-	y := 0
32-	for i := len(b.lines) - 1; 0 <= i; i-- {
33-		line := &b.lines[i]
34+	return bs.forEachLine(b, func(line *Line, y int) bool {
35 		if ymin <= y && line.Highlight {
36 			b.scrollAmt = y - bs.tlHeight + 1
37 			return true
38 		}
39-		y += len(line.NewLines(bs.ui.vx, bs.textWidth)) + 1
40-	}
41-	return false
42+		return false
43+	})
44 }
45 
46 func (bs *BufferList) ScrollDownHighlight() bool {
47 	b := bs.cur()
48 	yLastHighlight := 0
49-	y := 0
50-	for i := len(b.lines) - 1; 0 <= i && y < b.scrollAmt; i-- {
51-		line := &b.lines[i]
52+	bs.forEachLine(b, func(line *Line, y int) bool {
53+		if y >= b.scrollAmt {
54+			return true
55+		}
56 		if line.Highlight {
57 			yLastHighlight = y
58 		}
59-		y += len(line.NewLines(bs.ui.vx, bs.textWidth)) + 1
60-	}
61+		return false
62+	})
63 	b.scrollAmt = yLastHighlight
64 	return b.scrollAmt != 0
65 }
66@@ -700,6 +697,23 @@ func (bs *BufferList) cur() *buffer {
67 	return &bs.list[bs.current]
68 }
69 
70+func (bs *BufferList) forEachLine(b *buffer, f func(line *Line, y int) bool) bool {
71+	rulerDrawn := b.unreadSkip != optionalFalse || b.unreadRuler.IsZero() || b.title == ""
72+	y := 0
73+	for i := len(b.lines) - 1; 0 <= i; i-- {
74+		line := &b.lines[i]
75+		if !rulerDrawn && !line.At.After(b.unreadRuler) {
76+			rulerDrawn = true
77+			y++
78+		}
79+		if f(line, y) {
80+			return true
81+		}
82+		y += len(line.NewLines(bs.ui.vx, bs.textWidth)) + 1
83+	}
84+	return false
85+}
86+
87 func (bs *BufferList) DrawVerticalBufferList(vx *Vaxis, x0, y0, width, height int, offset *int) {
88 	if y0+len(bs.list)-*offset < height {
89 		*offset = y0 + len(bs.list) - height