From 67765541153687692bec339ec283f73e547f9392 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 27 Feb 2013 13:39:31 +0530
Subject: [PATCH] Only use scrollLeft if the bounding rect is obviously wrong,
 as scrollLeft is inaccurate in some cases.

---
 resources/compiled_coffeescript.zip         | Bin 67988 -> 68147 bytes
 src/calibre/ebooks/oeb/display/paged.coffee |  17 ++++++++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/resources/compiled_coffeescript.zip b/resources/compiled_coffeescript.zip
index 726167b97cb6473611e9ad552756f757e934febf..b90e6b50eaf8435e0a97c7bf7f2c8de9ca1bede2 100644
GIT binary patch
delta 361
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z9fh3Kw35vgZvUAkFE`V)P*BKBQ_x5%(ksa?P_R+ZH8e0V&{U}AQh)=HdIejs8G6OZ
zMfo{7K0uMlhJ~_xP${5p5NmSb39-qQo;Hj*n-6+E;+}q#ol#_STJkZ`&6OXna&FFT
z{lmF=ap-#9&6)iIiJSd?-R9Y>Qt8Me&d4OfjKvGn9oQLdK!(UMS%gha_$5017dxZ)
z^bZ_B0im4f0-TKc)8jy#=cQoT$sCMg(`!J=AJ>BgHUjMjDQB6!mV;4>X;Lppbn=9L
tw&}*4j9N^K-U0dY(^)xy?AG7Y4LKN<MOfKDA;|%R;Y<t+$JiNxJOJura=rin

delta 301
zcmdlyg=NZQ7U=+QW)=|!5LlKK?X>mF;_C^a3=AMFJ^dp)qufSI6F1@1oYY($1rS-R
zqfn4ol$uvEd4r(HWCs?G&CA?wGfkGA$1&N?NO-c1mog7XnO<>nQGQO2&*lWLN8Fp=
z*01N?>=brObaVf2OP<XyOIf%!&*>FN+$@uGm2>l&cei=O8JR?wu{dM;eRf8h>5QC=
za!fNrrz>(YYEGBt0CGH%K^)QP0UV6t)9-+!l`1DM{H-{B6$hghQ*tXr_B98i*mN(D
zY<xdNq@I&eXnH!xg!~T>kvSZUQqw1b)VTbbzLAqrQG}HZ6dD{r7|z7Npw7++<N*Lf
CA6W_j

diff --git a/src/calibre/ebooks/oeb/display/paged.coffee b/src/calibre/ebooks/oeb/display/paged.coffee
index 80aa9b9d7f..fdb83bf2f1 100644
--- a/src/calibre/ebooks/oeb/display/paged.coffee
+++ b/src/calibre/ebooks/oeb/display/paged.coffee
@@ -410,7 +410,22 @@ class PagedDisplay
         elem.scrollIntoView()
         if this.in_paged_mode
             # Ensure we are scrolled to the column containing elem
-            this.scroll_to_xpos(calibre_utils.viewport_to_document(elem.scrollLeft+this.margin_side, elem.scrollTop, elem.ownerDocument)[0])
+
+            # Because of a bug in WebKit's getBoundingClientRect() in column
+            # mode, this position can be inaccurate, see
+            # https://bugs.launchpad.net/calibre/+bug/1132641 for a test case.
+            # The usual symptom of the inaccuracy is br.top is highly negative.
+            br = elem.getBoundingClientRect()
+            if br.top < -1000
+                # This only works because of the preceding call to
+                # elem.scrollIntoView(). However, in some cases it gives
+                # inaccurate results, so we prefer the bounding client rect,
+                # when possible.
+                left = elem.scrollLeft
+            else
+                left = br.left
+            this.scroll_to_xpos(calibre_utils.viewport_to_document(
+                left+this.margin_side, elem.scrollTop, elem.ownerDocument)[0])
 
     snap_to_selection: () ->
         # Ensure that the viewport is positioned at the start of the column