Line breaking: fix tests by choosing longer (but still beyond the str…

…etchable tolerance) lines over shorter; note that this reverts a revert commit to fix #265, this fixes all cases

text/linebreak.go

@@ -293,6 +293,12 @@ func (lb *linebreaker) computeAdjustmentRatio(b int, active *Breakpoint) float64
 	}
 	ratio := 0.0
 	if L < lb.width {
+		if lb.Y-active.Y == 0.0 {
+			// unstretchable line, act as if we have a very small stretchable space.
+			// this helps to distinguish between between smaller and longer lines if both would
+			// need to stretched beyond the tolerance
+			return Infinity * (1.0 + (lb.width-L)/lb.width)
+		}
 		ratio = (lb.width - L) / (lb.Y - active.Y)
 	} else if lb.width < L {
 		ratio = (lb.width - L) / (lb.Z - active.Z)

text/linebreak_test.go

@@ -38,6 +38,9 @@ func TestLinebreak(t *testing.T) {
 		{[]Item{Box(50.0), P, Box(40.0), P, Box(50.0), P, Box(40.0), P, Box(50.0)}, "7>3>0", []float64{0.0, 0.0, 0.0}},
 		{[]Item{Box(30.0), P, Box(30.0), P, Box(30.0), P, Box(60.0), G, P, g, Box(60.0)}, "8>5>0", []float64{0.0, 0.0, 0.0}},
 
+		// CJK
+		{[]Item{Box(21.0), P, Box(21.0), P, Box(21.0), P, Box(21.0), P, Box(21.0), P, Box(21.0), P, Box(21.0), P, Box(21.0), P, Box(21.0)}, "15>7>0", []float64{0.0, 0.0, 0.0}},
+
 		// line too long
 		{[]Item{Box(120.0), P, Box(100.0)}, "1>0", []float64{0.0, 0.0}},
 	}