From 4e1fad39dce26930964fb8897b43d790ce08216c Mon Sep 17 00:00:00 2001
From: Guillaume Ayoub <guillaume.ayoub@kozea.fr>
Date: Thu, 22 Mar 2018 02:00:17 +0100
Subject: [PATCH] Fix floating-point number error to fix floating box layout

Fix #583.
---
 weasyprint/layout/inlines.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/weasyprint/layout/inlines.py b/weasyprint/layout/inlines.py
index 525de4092..458141748 100644
--- a/weasyprint/layout/inlines.py
+++ b/weasyprint/layout/inlines.py
@@ -132,6 +132,10 @@ def get_next_linebox(context, linebox, position_y, skip_stack,
         line.margin_bottom = 0
 
         line.translate(offset_x, offset_y)
+        # Avoid floating point errors, as position_y - top + top != position_y
+        # Removing this line breaks the position == linebox.position test below
+        # See https://github.com/Kozea/WeasyPrint/issues/583
+        line.position_y = position_y
 
         if line.height <= candidate_height:
             break