From 039b0a680d431de53f9f6f2f900f023278dc5285 Mon Sep 17 00:00:00 2001
From: Guillaume Ayoub <guillaume.ayoub@kozea.fr>
Date: Fri, 12 Apr 2019 16:04:25 +0200
Subject: [PATCH] Don't rely on iter_get_index to get current line break index

pango_layout_iter_get_index gives the visual order, not the logical order, so
we can't rely on this to fix the line break index.

Fix #828.
---
 weasyprint/tests/test_text.py | 24 ++++++++++++++++++++++--
 weasyprint/text.py            |  4 +++-
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/weasyprint/tests/test_text.py b/weasyprint/tests/test_text.py
index 8f9d305d5..3970f1a76 100644
--- a/weasyprint/tests/test_text.py
+++ b/weasyprint/tests/test_text.py
@@ -54,11 +54,31 @@ def test_line_breaking():
     assert resume_at is None
 
     _, _, resume_at, _, _, _ = make_text(string, 90, font_size=100)
-    assert string[resume_at:] == 'is a text for test'
+    assert string.encode('utf-8')[resume_at:].decode('utf-8') == (
+        'is a text for test')
 
     _, _, resume_at, _, _, _ = make_text(
         string, 100, font_family=SANS_FONTS.split(','), font_size=19)
-    assert string[resume_at:] == 'text for test'
+    assert string.encode('utf-8')[resume_at:].decode('utf-8') == (
+        'text for test')
+
+
+@assert_no_logs
+def test_line_breaking_rtl():
+    string = 'لوريم ايبسوم دولا'
+
+    # These two tests do not really rely on installed fonts
+    _, _, resume_at, _, _, _ = make_text(string, 90, font_size=1)
+    assert resume_at is None
+
+    _, _, resume_at, _, _, _ = make_text(string, 90, font_size=100)
+    assert string.encode('utf-8')[resume_at:].decode('utf-8') == (
+        'ايبسوم دولا')
+
+    _, _, resume_at, _, _, _ = make_text(
+        string, 100, font_family=SANS_FONTS.split(','), font_size=16)
+    assert string.encode('utf-8')[resume_at:].decode('utf-8') == (
+        'دولا')
 
 
 @assert_no_logs
diff --git a/weasyprint/text.py b/weasyprint/text.py
index 035074e93..f1a69d4e7 100644
--- a/weasyprint/text.py
+++ b/weasyprint/text.py
@@ -718,7 +718,9 @@ def get_first_line(self):
             pango.pango_layout_iter_free)
         first_line = pango.pango_layout_iter_get_line_readonly(layout_iter)
         if pango.pango_layout_iter_next_line(layout_iter):
-            index = pango.pango_layout_iter_get_index(layout_iter)
+            second_line = pango.pango_layout_iter_get_line_readonly(
+                layout_iter)
+            index = second_line.start_index
         else:
             index = None
         return first_line, index