From 59d891798f9fce13f557aabc981b217bad318b52 Mon Sep 17 00:00:00 2001
From: Robert O'Callahan <robert@ocallahan.org>
Date: Mon, 29 Mar 2010 14:46:59 +1300
Subject: [PATCH] Bug 548792. Let the search for a scrollable parent cross
 document boundaries. r=mats

---
 layout/base/nsPresShell.cpp                   |  4 +++-
 .../test_scroll_selection_into_view.html      | 24 +++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/layout/base/nsPresShell.cpp b/layout/base/nsPresShell.cpp
index 7d7da57b62c4..006e0fd0223a 100644
--- a/layout/base/nsPresShell.cpp
+++ b/layout/base/nsPresShell.cpp
@@ -4129,7 +4129,9 @@ PresShell::ScrollFrameRectIntoView(nsIFrame*     aFrame,
       rect.IntersectRect(rect, sf->GetScrollPortRect());
     }
     rect += container->GetPosition();
-    container = container->GetParent();
+    nsPoint extraOffset(0,0);
+    container = nsLayoutUtils::GetCrossDocParentFrame(container, &extraOffset);
+    rect += extraOffset;
   } while (container);
 
   return didScroll;
diff --git a/layout/base/tests/test_scroll_selection_into_view.html b/layout/base/tests/test_scroll_selection_into_view.html
index 031648e0896b..5c02e60478c2 100644
--- a/layout/base/tests/test_scroll_selection_into_view.html
+++ b/layout/base/tests/test_scroll_selection_into_view.html
@@ -30,6 +30,17 @@
   </div>
   <div style="height:400px;"></div>
 </div>
+<div id="c4" style="overflow-y:scroll; width:200px; height:200px; position:absolute; top:200px; left:600px;">
+  <iframe id="target4" style="border:none; width:100%; height:1100px; display:block;"
+          src="data:text/html,
+               <body style='margin:0; overflow:hidden;'>
+                 <div style='height:400px;'></div>
+                 <div><span id='target4'
+                            style='display:inline-block; vertical-align:top; height:300px;'>target4</span>
+                 </div>
+                 <div style='height:400px;'></div>">
+  </iframe>
+</div>
 
 <pre id="test">
 <script class="testbody" type="text/javascript">
@@ -43,6 +54,9 @@ function testCollapsed(id, vPercent, startAt, expected) {
 
   var c = document.getElementById("c" + id);
   var target = document.getElementById("target" + id);
+  if (target.contentDocument) {
+    target = target.contentDocument.getElementById("target" + id);
+  }
   selection.collapse(target.parentNode, 0);
   c.scrollTop = startAt;
   selection.scrollIntoView(FOCUS, true, vPercent, 0);
@@ -78,6 +92,16 @@ function doTest() {
   // visible.
   testCollapsed("3", -1, 1000, 400);
 
+  // Test scrolling an element larger than the scrollport
+  testCollapsed("4", 0, 0, 400);
+  testCollapsed("4", 100, 0, 500);
+  testCollapsed("4", -1, 0, 400);
+  testCollapsed("4", 0, 1000, 400);
+  testCollapsed("4", 100, 1000, 500);
+  // If the element can't be completely visible, we make the top edge
+  // visible.
+  testCollapsed("4", -1, 1000, 400);
+
   SimpleTest.finish();
 }
 
