--- a/layout/generic/TextOverflow.cpp
+++ b/layout/generic/TextOverflow.cpp
@@ -272,21 +272,21 @@ TextOverflow::WillProcessLines(nsDisplay
   nsIScrollableFrame* scroll =
     nsLayoutUtils::GetScrollableFrameFor(aBlockFrame);
   textOverflow->mCanHaveHorizontalScrollbar = false;
   if (scroll) {
     textOverflow->mCanHaveHorizontalScrollbar =
       scroll->GetScrollbarStyles().mHorizontal != NS_STYLE_OVERFLOW_HIDDEN;
     textOverflow->mContentArea.MoveBy(scroll->GetScrollPosition());
   }
-  textOverflow->mBlockIsRTL =
-    aBlockFrame->GetStyleVisibility()->mDirection == NS_STYLE_DIRECTION_RTL;
+  PRUint8 direction = aBlockFrame->GetStyleVisibility()->mDirection;
+  textOverflow->mBlockIsRTL = direction == NS_STYLE_DIRECTION_RTL;
   const nsStyleTextReset* style = aBlockFrame->GetStyleTextReset();
-  textOverflow->mLeft.Init(style->mTextOverflow.mLeft);
-  textOverflow->mRight.Init(style->mTextOverflow.mRight);
+  textOverflow->mLeft.Init(*style->mTextOverflow.GetLeft(direction));
+  textOverflow->mRight.Init(*style->mTextOverflow.GetRight(direction));
   // The left/right marker string is setup in ExamineLineFrames when a line
   // has overflow on that side.
 
   return textOverflow.forget();
 }
 
 void
 TextOverflow::DidProcessLines()
@@ -397,41 +397,41 @@ TextOverflow::AnalyzeMarkerEdges(nsIFram
   }
 }
 
 void
 TextOverflow::ExamineLineFrames(nsLineBox*      aLine,
                                 FrameHashtable* aFramesToHide,
                                 AlignmentEdges* aAlignmentEdges)
 {
+  // No ellipsing for 'clip' style.
+  bool suppressLeft = mLeft.mStyle->mType == NS_STYLE_TEXT_OVERFLOW_CLIP;
+  bool suppressRight = mRight.mStyle->mType == NS_STYLE_TEXT_OVERFLOW_CLIP;
+
   // Scrolling to the end position can leave some text still overflowing due to
   // pixel snapping behaviour in our scrolling code so we move the edges 1px
   // outward to avoid triggering a text-overflow marker for such overflow.
   nsRect contentArea = mContentArea;
   const nscoord scrollAdjust = mCanHaveHorizontalScrollbar ?
     mBlock->PresContext()->AppUnitsPerDevPixel() : 0;
-  InflateLeft(&contentArea,
-              mLeft.mStyle->mType == NS_STYLE_TEXT_OVERFLOW_CLIP,
-              scrollAdjust);
-  InflateRight(&contentArea,
-               mRight.mStyle->mType == NS_STYLE_TEXT_OVERFLOW_CLIP,
-               scrollAdjust);
+  InflateLeft(&contentArea, suppressLeft, scrollAdjust);
+  InflateRight(&contentArea, suppressRight, scrollAdjust);
   nsRect lineRect = aLine->GetScrollableOverflowArea();
-  const bool leftOverflow = lineRect.x < contentArea.x;
-  const bool rightOverflow = lineRect.XMost() > contentArea.XMost();
+  const bool leftOverflow =
+    !suppressLeft && lineRect.x < contentArea.x;
+  const bool rightOverflow =
+    !suppressRight && lineRect.XMost() > contentArea.XMost();
   if (!leftOverflow && !rightOverflow) {
-    // The line does not overflow - no need to traverse the frame tree.
+    // The line does not overflow on a side we should ellipsize.
     return;
   }
 
   PRUint32 pass = 0;
-  bool guessLeft =
-    mLeft.mStyle->mType != NS_STYLE_TEXT_OVERFLOW_CLIP && leftOverflow;
-  bool guessRight =
-    mRight.mStyle->mType != NS_STYLE_TEXT_OVERFLOW_CLIP && rightOverflow;
+  bool guessLeft = leftOverflow;
+  bool guessRight = rightOverflow;
   do {
     // Setup marker strings as needed.
     if (guessLeft) {
       mLeft.SetupString(mBlock);
     }
     if (guessRight) {
       mRight.SetupString(mBlock);
     }

--- a/layout/reftests/text-overflow/bidi-simple-scrolled.html
+++ b/layout/reftests/text-overflow/bidi-simple-scrolled.html
@@ -12,17 +12,17 @@
   font-family: DejaVuSansMono;
   src: url(../fonts/DejaVuSansMono.woff);
 }
 html,body {
     color:black; background-color:white; font-size:16px; padding:0; margin:0; font-family:DejaVuSansMono;
 }
 .test {
   overflow:auto;
-  text-overflow:ellipsis;
+  text-overflow:ellipsis ellipsis;
   white-space:nowrap;
   width: 4.4em;
   margin-bottom:1em;
   position:relative;
   line-height:2em;
 }
 
 .hidden {

--- a/layout/reftests/text-overflow/ellipsis-font-fallback.html
+++ b/layout/reftests/text-overflow/ellipsis-font-fallback.html
@@ -26,17 +26,17 @@ html,body {
 .rlo {
   unicode-bidi: bidi-override; direction: rtl;
 }
 .lro {
   unicode-bidi: bidi-override; direction: ltr;
 }
 
 .o {
-  text-overflow: ellipsis;
+  text-overflow: ellipsis ellipsis;
   color:blue;
 }
 .o span {
   color:black;
 }
 
 .s {
   width:10em;

--- a/layout/reftests/text-overflow/false-marker-overlap.html
+++ b/layout/reftests/text-overflow/false-marker-overlap.html
@@ -14,17 +14,17 @@
 }
 html,body {
     color:black; background-color:white; font-size:16px; padding:0; margin:0; font-family:DejaVuSansMono;
 }
 
 .test { 
   overflow: hidden; 
   white-space: nowrap;
-  text-overflow: ellipsis;
+  text-overflow: ellipsis ellipsis;
   color: black;
   height: 6em;
   width: 32.5em;
   margin-bottom: 1em;
 }
 
 i {
   display:inline-block;

--- a/layout/reftests/text-overflow/marker-basic-ref.html
+++ b/layout/reftests/text-overflow/marker-basic-ref.html
@@ -129,16 +129,18 @@ x1 m { position:absolute; right:0; font-
 #test8a  { top:280px; left:0;     position:absolute; }
 #test8b  { top:280px; left:100px; position:absolute; }
 #test8c  { top:280px; left:200px; position:absolute; }
 #test8d  { top:280px; left:300px; position:absolute; }
 #test9a  { top:320px; left:0;     position:absolute; border:1px solid black; }
 #test9b  { top:320px; left:100px; position:absolute; border:1px solid black; }
 #test9c  { top:320px; left:200px; position:absolute; border:1px solid black; }
 #test9d  { top:320px; left:300px; position:absolute; border:1px solid black; }
+#test10a { top:360px; left:0;     position:absolute; }
+#test10b { top:360px; left:100px; position:absolute; }
 
     </style>
 </head>
 <body>
 <div style="position: absolute; top:20px; left:50px;">
 
 <div id="test1a">
 <div class="s a"><div class="p rel">
@@ -294,12 +296,15 @@ x1 m { position:absolute; right:0; font-
 <div id="test8a"><div class="s a"><div class="a p ltr"><span class="c5 a"></span><span class="e"></span><span style="margin-right:-0.5em">&#x2026;</span><span>&#x200c;</span></div></div></div>
 <div id="test8d"><div class="s a"><div class="a p rtl"><span class="c5 a"></span><span class="e"></span><span style="margin-right:-0.5em">&#x2026;</span><span>&#x200c;</span></div></div></div>
 
 <div id="test9a"><div class="s a"><div class="p ltr"><span class="e"></span><i>&nbsp;&nbsp;&nbsp;&nbsp;</i><m>&#x2026;</m><span class="e a"></span></div></div></div>
 <div id="test9b"><div class="s a"><div class="p rtl"><span class="e"></span><i>&nbsp;&nbsp;&nbsp;&nbsp;</i><m>&#x2026;</m><span class="e a"></span></div></div></div>
 <div id="test9c"><div class="s a"><div class="p ltr"><span class="e"></span><i>&nbsp;&nbsp;&nbsp;&nbsp;</i><m>&#x2026;</m><span class="e a"></span></div></div></div>
 <div id="test9d"><div class="s a"><div class="p rtl"><span class="e"></span><i>&nbsp;&nbsp;&nbsp;&nbsp;</i><m>&#x2026;</m><span class="e a"></span></div></div></div>
 
+<!-- no marker for overflow:auto that doesn't trigger scrollbar -->
+<div id="test10a"><div class="s a"><div class="p o ltr"><span style="margin-left:-5px" >||||||</span></div></div></div>
+<div id="test10b"><div class="s a"><div class="p o rtl"><span style="margin-right:-5px">||||||</span></div></div></div>
 
 </div>
 </body>
 </html>

--- a/layout/reftests/text-overflow/marker-basic.html
+++ b/layout/reftests/text-overflow/marker-basic.html
@@ -25,17 +25,17 @@ html,body {
 .rlo {
   unicode-bidi: bidi-override; direction: rtl;
 }
 .lro {
   unicode-bidi: bidi-override; direction: ltr;
 }
 
 .o {
-  text-overflow: ellipsis;
+  text-overflow: ellipsis ellipsis;
 }
 
 .rel {
   position: relative;
   height:2em;
 }
 .abs0 {
   position: absolute;
@@ -45,16 +45,19 @@ html,body {
 .s {
   width:4em;
 }
 .p {
   overflow: hidden;
   white-space:nowrap;
   font-size:16px;
 }
+.auto {
+  overflow: auto;
+}
 .r {
   text-align:right;
 }
 .a {
   font-size:20px;
 }
 .l {
   text-align:left;
@@ -126,16 +129,18 @@ i {
 #test8a  { top:280px; left:0;     position:absolute; }
 #test8b  { top:280px; left:100px; position:absolute; }
 #test8c  { top:280px; left:200px; position:absolute; }
 #test8d  { top:280px; left:300px; position:absolute; }
 #test9a  { top:320px; left:0;     position:absolute; border:1px solid black; }
 #test9b  { top:320px; left:100px; position:absolute; border:1px solid black; }
 #test9c  { top:320px; left:200px; position:absolute; border:1px solid black; }
 #test9d  { top:320px; left:300px; position:absolute; border:1px solid black; }
+#test10a { top:360px; left:0;     position:absolute; }
+#test10b { top:360px; left:100px; position:absolute; }
 
 
     </style>
 </head>
 <body>
 <div style="position: absolute; top:20px; left:50px;">
 
 <!-- start + end marker, aligned to text -->
@@ -186,12 +191,15 @@ i {
 <div id="test8d"><div class="s a"><div class="a p o rtl"><span class="c5 a">|</span><span class="e"></span><span>&#x200c;</span></div></div></div>
 
 <!-- end marker, marker aligns to inline block with overflow -->
 <div id="test9a"><div class="s a"><div class="p o ltr"><span class="e"></span><i>&nbsp;&nbsp;&nbsp;&nbsp;</i><span class="e"></span><span class="c5 a">|||</span></div></div></div>
 <div id="test9b"><div class="s a"><div class="p o rtl"><span class="e"></span><i>&nbsp;&nbsp;&nbsp;&nbsp;</i><span class="e"></span><span class="c5 a">|||</span></div></div></div>
 <div id="test9c"><div class="s a"><div class="p o ltr"><span class="e"></span><i>&nbsp;&nbsp;&nbsp;&nbsp;</i><span class="e"></span><span class="c5 a">|||</span></div></div></div>
 <div id="test9d"><div class="s a"><div class="p o rtl"><span class="e"></span><i>&nbsp;&nbsp;&nbsp;&nbsp;</i><span class="e"></span><span class="c5 a">|||</span></div></div></div>
 
+<!-- no marker for overflow:auto that doesn't trigger scrollbar -->
+<div id="test10a"><div class="s a"><div class="p o ltr auto"><span style="margin-left:-5px" >||||||</span></div></div></div>
+<div id="test10b"><div class="s a"><div class="p o rtl auto"><span style="margin-right:-5px">||||||</span></div></div></div>
+
 </div>
-
 </body>
 </html>

--- a/layout/reftests/text-overflow/marker-string.html
+++ b/layout/reftests/text-overflow/marker-string.html
@@ -39,19 +39,19 @@ s {
 }
 .rtl {
   direction:rtl;
 }
 .ltr {
   direction:ltr;
 }
 
-.t1 { text-overflow:""; }
-.t2 { text-overflow:"Hello World"; }
-.t3 { text-overflow:"X"; }
+.t1 { text-overflow:"" ""; }
+.t2 { text-overflow:"Hello World" "Hello World"; }
+.t3 { text-overflow:"X" "X"; }
 
 </style>
 
 </head><body>
 
 
 <!-- Empty marker clips text -->
 <div class="test t1"><span>xx</span></div>

--- a/layout/reftests/text-overflow/reftest.list
+++ b/layout/reftests/text-overflow/reftest.list
@@ -14,8 +14,9 @@ HTTP(..) == standards-decorations.html s
 HTTP(..) == standards-line-height.html standards-line-height-ref.html
 HTTP(..) == selection.html selection-ref.html
 HTTP(..) == marker-shadow.html marker-shadow-ref.html
 == aligned-baseline.html aligned-baseline-ref.html
 skip-if(Android) == clipped-elements.html clipped-elements-ref.html
 == theme-overflow.html theme-overflow-ref.html
 HTTP(..) == table-cell.html table-cell-ref.html
 HTTP(..) == two-value-syntax.html two-value-syntax-ref.html
+HTTP(..) == single-value.html single-value-ref.html 

--- a/layout/reftests/text-overflow/selection.html
+++ b/layout/reftests/text-overflow/selection.html
@@ -18,17 +18,17 @@
   src: url(TestEllipsisFallback.woff);
 }
 html,body {
     color:black; background-color:white; font-size:16px; padding:0; margin:0; font-family:DejaVuSansMono;
 }
 
 .test {
   overflow:auto;
-  text-overflow:ellipsis;
+  text-overflow:ellipsis ellipsis;
   white-space:nowrap;
   width: 5em;
   position:relative;
   margin-top:1em;
   padding-left: 0.9em;
   padding-right: 1.3em;
 }
 

new file mode 100644
--- /dev/null
+++ b/layout/reftests/text-overflow/single-value-ref.html
@@ -0,0 +1,105 @@
+<!DOCTYPE HTML>
+<!--
+    Any copyright is dedicated to the Public Domain.
+    http://creativecommons.org/licenses/publicdomain/
+
+    Test: text-overflow: <single value>, scrolled and non-scrolled tests, (bug 684266)
+-->
+<html class="reftest-wait"><head>
+<title>text-overflow: &lt;single value&gt;, scrolled and non-scrolled tests, (bug 684266)</title>
+<style type="text/css">
+@font-face {
+  font-family: DejaVuSansMono;
+  src: url(../fonts/DejaVuSansMono.woff),url(DejaVuSansMono.woff);
+}
+html,body {
+    color:black; background-color:white; font-size:16px; padding:0; margin:0; font-family:DejaVuSansMono;
+}
+
+body {padding:10px 40px;}
+
+div {
+  width:100px;
+  white-space:nowrap;
+}
+.hidden {overflow:hidden}
+.auto {overflow:auto}
+.autolong {overflow:auto; width:100%;}
+.scroll {overflow:scroll}
+
+.ltr { direction:ltr; unicode-bidi: bidi-override; }
+.rtl { direction:rtl; unicode-bidi: bidi-override; }
+
+.ltr.p { text-indent: -5px; padding-left: 40px; } /* overflow into padding, but not outside the padding edge */
+.rtl.p { text-indent: -5px; padding-right: 40px; } /* overflow into padding, but not outside the padding edge */
+
+.s { text-indent: -5px; } /* overflow start edge outside the padding edge */
+
+div.ltr {
+  text-overflow: clip ellipsis;
+}
+div.rtl {
+  text-overflow: ellipsis clip;
+}
+
+</style>
+
+<script>
+function scrolldivs() {
+ var divs = document.getElementsByTagName('div');
+  for (i = 0; i < divs.length; ++i) {
+    var elm = divs[i];
+    if (elm.hasAttribute('scroll')) {
+      if (window.getComputedStyle(elm).direction == 'ltr')
+        elm.scrollLeft = 8;
+      else
+        elm.scrollLeft = -8;
+    }
+  }
+  document.documentElement.removeAttribute('class');
+}
+</script>
+</head>
+<body onload="scrolldivs()">
+
+    <div class="ltr start p hidden">A long line that does not break (overflow:hidden)</div>
+    <div class="ltr start p auto">A long line that does not break (overflow:auto)</div>
+    <div class="ltr start p autolong">A long line that does not break (overflow:auto)</div>
+    <div class="ltr start p scroll">A long line that does not break (overflow:scroll)</div>
+    <div class="ltr start s hidden">A long line that does not break (overflow:hidden)</div>
+    <div class="ltr start s auto">A long line that does not break (overflow:auto)</div>
+    <div class="ltr start s autolong">A long line that does not break (overflow:auto)</div>
+    <div class="ltr start s scroll">A long line that does not break (overflow:scroll)</div>
+
+    <div scroll class="ltr start p hidden">A long line that does not break (overflow:hidden)</div>
+    <div scroll class="ltr start p auto">A long line that does not break (overflow:auto)</div>
+    <div scroll class="ltr start p autolong">A long line that does not break (overflow:auto)</div>
+    <div scroll class="ltr start p scroll">A long line that does not break (overflow:scroll)</div>
+    <div scroll class="ltr start s hidden">A long line that does not break (overflow:hidden)</div>
+    <div scroll class="ltr start s auto">A long line that does not break (overflow:auto)</div>
+    <div scroll class="ltr start s autolong">A long line that does not break (overflow:auto)</div>
+    <div scroll class="ltr start s scroll">A long line that does not break (overflow:scroll)</div>
+
+<div class="rtl" style="float:right">
+    <div class="rtl start p hidden">A long line that does not break (overflow:hidden)</div>
+    <div class="rtl start p auto">A long line that does not break (overflow:auto)</div>
+    <div class="rtl start p autolong">A long line that does not break (overflow:auto)</div>
+    <div class="rtl start p scroll">A long line that does not break (overflow:scroll)</div>
+    <div class="rtl start s hidden">A long line that does not break (overflow:hidden)</div>
+    <div class="rtl start s auto">A long line that does not break (overflow:auto)</div>
+    <div class="rtl start s autolong">A long line that does not break (overflow:auto)</div>
+    <div class="rtl start s scroll">A long line that does not break (overflow:scroll)</div>
+
+    <div scroll class="rtl start p hidden">A long line that does not break (overflow:hidden)</div>
+    <div scroll class="rtl start p auto">A long line that does not break (overflow:auto)</div>
+    <div scroll class="rtl start p autolong">A long line that does not break (overflow:auto)</div>
+    <div scroll class="rtl start p scroll">A long line that does not break (overflow:scroll)</div>
+    <div scroll class="rtl start s hidden">A long line that does not break (overflow:hidden)</div>
+    <div scroll class="rtl start s auto">A long line that does not break (overflow:auto)</div>
+    <div scroll class="rtl start s autolong">A long line that does not break (overflow:auto)</div>
+    <div scroll class="rtl start s scroll">A long line that does not break (overflow:scroll)</div>
+</div>
+
+
+</body>
+</hml>

new file mode 100644
--- /dev/null
+++ b/layout/reftests/text-overflow/single-value.html
@@ -0,0 +1,98 @@
+<!DOCTYPE HTML>
+<!--
+    Any copyright is dedicated to the Public Domain.
+    http://creativecommons.org/licenses/publicdomain/
+
+    Test: text-overflow: <single value>, scrolled and non-scrolled tests, (bug 684266)
+-->
+<html class="reftest-wait"><head>
+<title>text-overflow: &lt;single value&gt;, scrolled and non-scrolled tests, (bug 684266)</title>
+<style type="text/css">
+@font-face {
+  font-family: DejaVuSansMono;
+  src: url(../fonts/DejaVuSansMono.woff),url(DejaVuSansMono.woff);
+}
+html,body {
+    color:black; background-color:white; font-size:16px; padding:0; margin:0; font-family:DejaVuSansMono;
+}
+
+body {padding:10px 40px;}
+
+div {
+  text-overflow: ellipsis;
+  width:100px;
+  white-space:nowrap;
+}
+.hidden {overflow:hidden}
+.auto {overflow:auto}
+.autolong {overflow:auto; width:100%;}
+.scroll {overflow:scroll}
+
+.ltr { direction:ltr; unicode-bidi: bidi-override; }
+.rtl { direction:rtl; unicode-bidi: bidi-override; }
+
+.ltr.p { text-indent: -5px; padding-left: 40px; } /* overflow into padding, but not outside the padding edge */
+.rtl.p { text-indent: -5px; padding-right: 40px; } /* overflow into padding, but not outside the padding edge */
+
+.s { text-indent: -5px; } /* overflow start edge outside the padding edge */
+</style>
+
+<script>
+function scrolldivs() {
+ var divs = document.getElementsByTagName('div');
+  for (i = 0; i < divs.length; ++i) {
+    var elm = divs[i];
+    if (elm.hasAttribute('scroll')) {
+      if (window.getComputedStyle(elm).direction == 'ltr')
+        elm.scrollLeft = 8;
+      else
+        elm.scrollLeft = -8;
+    }
+  }
+  document.documentElement.removeAttribute('class');
+}
+</script>
+</head>
+<body onload="scrolldivs()">
+
+    <div class="ltr start p hidden">A long line that does not break (overflow:hidden)</div>
+    <div class="ltr start p auto">A long line that does not break (overflow:auto)</div>
+    <div class="ltr start p autolong">A long line that does not break (overflow:auto)</div>
+    <div class="ltr start p scroll">A long line that does not break (overflow:scroll)</div>
+    <div class="ltr start s hidden">A long line that does not break (overflow:hidden)</div>
+    <div class="ltr start s auto">A long line that does not break (overflow:auto)</div>
+    <div class="ltr start s autolong">A long line that does not break (overflow:auto)</div>
+    <div class="ltr start s scroll">A long line that does not break (overflow:scroll)</div>
+
+    <div scroll class="ltr start p hidden">A long line that does not break (overflow:hidden)</div>
+    <div scroll class="ltr start p auto">A long line that does not break (overflow:auto)</div>
+    <div scroll class="ltr start p autolong">A long line that does not break (overflow:auto)</div>
+    <div scroll class="ltr start p scroll">A long line that does not break (overflow:scroll)</div>
+    <div scroll class="ltr start s hidden">A long line that does not break (overflow:hidden)</div>
+    <div scroll class="ltr start s auto">A long line that does not break (overflow:auto)</div>
+    <div scroll class="ltr start s autolong">A long line that does not break (overflow:auto)</div>
+    <div scroll class="ltr start s scroll">A long line that does not break (overflow:scroll)</div>
+
+<div class="rtl" style="float:right">
+    <div class="rtl start p hidden">A long line that does not break (overflow:hidden)</div>
+    <div class="rtl start p auto">A long line that does not break (overflow:auto)</div>
+    <div class="rtl start p autolong">A long line that does not break (overflow:auto)</div>
+    <div class="rtl start p scroll">A long line that does not break (overflow:scroll)</div>
+    <div class="rtl start s hidden">A long line that does not break (overflow:hidden)</div>
+    <div class="rtl start s auto">A long line that does not break (overflow:auto)</div>
+    <div class="rtl start s autolong">A long line that does not break (overflow:auto)</div>
+    <div class="rtl start s scroll">A long line that does not break (overflow:scroll)</div>
+
+    <div scroll class="rtl start p hidden">A long line that does not break (overflow:hidden)</div>
+    <div scroll class="rtl start p auto">A long line that does not break (overflow:auto)</div>
+    <div scroll class="rtl start p autolong">A long line that does not break (overflow:auto)</div>
+    <div scroll class="rtl start p scroll">A long line that does not break (overflow:scroll)</div>
+    <div scroll class="rtl start s hidden">A long line that does not break (overflow:hidden)</div>
+    <div scroll class="rtl start s auto">A long line that does not break (overflow:auto)</div>
+    <div scroll class="rtl start s autolong">A long line that does not break (overflow:auto)</div>
+    <div scroll class="rtl start s scroll">A long line that does not break (overflow:scroll)</div>
+</div>
+
+
+</body>
+</hml>

--- a/layout/reftests/text-overflow/theme-overflow.html
+++ b/layout/reftests/text-overflow/theme-overflow.html
@@ -2,17 +2,17 @@
 <html>
 <head>
   <meta http-equiv="content-type" content="text/html; charset=UTF-8">
   <title>Testcase for bug 669284</title>
   
   <style type="text/css">
     p {
       overflow: hidden;
-      text-overflow: ellipsis;
+      text-overflow: ellipsis ellipsis;
       width: 200px;
     }
     .r {
       direction:rtl;
     }
 
 .x0 { margin:0px;}
 .x1 { margin:1px;}

--- a/layout/style/nsCSSParser.cpp
+++ b/layout/style/nsCSSParser.cpp
@@ -8181,18 +8181,19 @@ CSSParserImpl::ParseTextOverflow(nsCSSVa
   if (!ParseVariant(left, VARIANT_KEYWORD | VARIANT_STRING,
                     nsCSSProps::kTextOverflowKTable))
     return PR_FALSE;
 
   nsCSSValue right;
   if (ParseVariant(right, VARIANT_KEYWORD | VARIANT_STRING,
                     nsCSSProps::kTextOverflowKTable))
     aValue.SetPairValue(left, right);
-  else
-    aValue.SetPairValue(left, left);
+  else {
+    aValue = left;
+  }
   return PR_TRUE;
 }
 
 bool
 CSSParserImpl::ParseTransitionProperty()
 {
   nsCSSValue value;
   if (ParseVariant(value, VARIANT_INHERIT | VARIANT_NONE | VARIANT_ALL,

--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -2481,43 +2481,45 @@ nsComputedDOMStyle::DoGetTextIndent()
                   &nsComputedDOMStyle::GetCBContentWidth);
   return val;
 }
 
 nsIDOMCSSValue*
 nsComputedDOMStyle::DoGetTextOverflow()
 {
   const nsStyleTextReset *style = GetStyleTextReset();
-  nsROCSSPrimitiveValue *left = GetROCSSPrimitiveValue();
-  if (style->mTextOverflow.mLeft.mType == NS_STYLE_TEXT_OVERFLOW_STRING) {
+  nsROCSSPrimitiveValue *first = GetROCSSPrimitiveValue();
+  const nsStyleTextOverflowSide *side = style->mTextOverflow.GetFirstValue();
+  if (side->mType == NS_STYLE_TEXT_OVERFLOW_STRING) {
     nsString str;
-    nsStyleUtil::AppendEscapedCSSString(style->mTextOverflow.mLeft.mString, str);
-    left->SetString(str);
+    nsStyleUtil::AppendEscapedCSSString(side->mString, str);
+    first->SetString(str);
   } else {
-    left->SetIdent(
-      nsCSSProps::ValueToKeywordEnum(style->mTextOverflow.mLeft.mType,
+    first->SetIdent(
+      nsCSSProps::ValueToKeywordEnum(side->mType,
                                      nsCSSProps::kTextOverflowKTable));
   }
-  if (style->mTextOverflow.mLeft == style->mTextOverflow.mRight) {
-    return left;
+  side = style->mTextOverflow.GetSecondValue();
+  if (!side) {
+    return first;
   }
-  nsROCSSPrimitiveValue *right = GetROCSSPrimitiveValue();
-  if (style->mTextOverflow.mRight.mType == NS_STYLE_TEXT_OVERFLOW_STRING) {
+  nsROCSSPrimitiveValue *second = GetROCSSPrimitiveValue();
+  if (side->mType == NS_STYLE_TEXT_OVERFLOW_STRING) {
     nsString str;
-    nsStyleUtil::AppendEscapedCSSString(style->mTextOverflow.mRight.mString, str);
-    right->SetString(str);
+    nsStyleUtil::AppendEscapedCSSString(side->mString, str);
+    second->SetString(str);
   } else {
-    right->SetIdent(
-      nsCSSProps::ValueToKeywordEnum(style->mTextOverflow.mRight.mType,
+    second->SetIdent(
+      nsCSSProps::ValueToKeywordEnum(side->mType,
                                      nsCSSProps::kTextOverflowKTable));
   }
 
   nsDOMCSSValueList *valueList = GetROCSSValueList(PR_FALSE);
-  valueList->AppendCSSValue(left);
-  valueList->AppendCSSValue(right);
+  valueList->AppendCSSValue(first);
+  valueList->AppendCSSValue(second);
   return valueList;
 }
 
 nsIDOMCSSValue*
 nsComputedDOMStyle::DoGetTextShadow()
 {
   return GetCSSShadowArray(GetStyleText()->mTextShadow,
                            GetStyleColor()->mColor,

--- a/layout/style/nsRuleNode.cpp
+++ b/layout/style/nsRuleNode.cpp
@@ -3489,25 +3489,44 @@ nsRuleNode::ComputeTextResetData(void* a
     text->SetDecorationStyle(decorationStyleValue->GetIntValue());
   } else if (eCSSUnit_Inherit == decorationStyleValue->GetUnit()) {
     text->SetDecorationStyle(parentText->GetDecorationStyle());
     canStoreInRuleTree = PR_FALSE;
   } else if (eCSSUnit_Initial == decorationStyleValue->GetUnit()) {
     text->SetDecorationStyle(NS_STYLE_TEXT_DECORATION_STYLE_SOLID);
   }
 
-  // text-overflow: pair(enum|string), inherit, initial
+  // text-overflow: enum, string, pair(enum|string), inherit, initial
   const nsCSSValue* textOverflowValue =
     aRuleData->ValueForTextOverflow();
   if (eCSSUnit_Initial == textOverflowValue->GetUnit()) {
     text->mTextOverflow = nsStyleTextOverflow();
   } else if (eCSSUnit_Inherit == textOverflowValue->GetUnit()) {
     canStoreInRuleTree = PR_FALSE;
     text->mTextOverflow = parentText->mTextOverflow;
+  } else if (eCSSUnit_Enumerated == textOverflowValue->GetUnit()) {
+    // A single enumerated value.
+    SetDiscrete(*textOverflowValue, text->mTextOverflow.mRight.mType,
+                canStoreInRuleTree,
+                SETDSC_ENUMERATED, parentText->mTextOverflow.mRight.mType,
+                NS_STYLE_TEXT_OVERFLOW_CLIP, 0, 0, 0, 0);
+    text->mTextOverflow.mRight.mString.Truncate();
+    text->mTextOverflow.mLeft.mType = NS_STYLE_TEXT_OVERFLOW_CLIP;
+    text->mTextOverflow.mLeft.mString.Truncate();
+    text->mTextOverflow.mLogicalDirections = true;
+  } else if (eCSSUnit_String == textOverflowValue->GetUnit()) {
+    // A single string value.
+    text->mTextOverflow.mRight.mType = NS_STYLE_TEXT_OVERFLOW_STRING;
+    textOverflowValue->GetStringValue(text->mTextOverflow.mRight.mString);
+    text->mTextOverflow.mLeft.mType = NS_STYLE_TEXT_OVERFLOW_CLIP;
+    text->mTextOverflow.mLeft.mString.Truncate();
+    text->mTextOverflow.mLogicalDirections = true;
   } else if (eCSSUnit_Pair == textOverflowValue->GetUnit()) {
+    // Two values were specified.
+    text->mTextOverflow.mLogicalDirections = false;
     const nsCSSValuePair& textOverflowValue =
       aRuleData->ValueForTextOverflow()->GetPairValue();
 
     const nsCSSValue *textOverflowLeftValue = &textOverflowValue.mXValue;
     if (eCSSUnit_Enumerated == textOverflowLeftValue->GetUnit()) {
       SetDiscrete(*textOverflowLeftValue, text->mTextOverflow.mLeft.mType,
                   canStoreInRuleTree,
                   SETDSC_ENUMERATED, parentText->mTextOverflow.mLeft.mType,

--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -1143,25 +1143,53 @@ struct nsStyleTextOverflowSide {
     return !(*this == aOther);
   }
 
   nsString mString;
   PRUint8  mType;
 };
 
 struct nsStyleTextOverflow {
+  nsStyleTextOverflow() : mLogicalDirections(true) {}
   bool operator==(const nsStyleTextOverflow& aOther) const {
     return mLeft == aOther.mLeft && mRight == aOther.mRight;
   }
   bool operator!=(const nsStyleTextOverflow& aOther) const {
     return !(*this == aOther);
   }
 
-  nsStyleTextOverflowSide mLeft;
-  nsStyleTextOverflowSide mRight;
+  // Returns the value to apply on the left side.
+  const nsStyleTextOverflowSide& GetLeft(PRUint8 aDirection) const {
+    NS_ASSERTION(aDirection == NS_STYLE_DIRECTION_LTR ||
+                 aDirection == NS_STYLE_DIRECTION_RTL, "bad direction");
+    return !mLogicalDirections || aDirection == NS_STYLE_DIRECTION_LTR ?
+             mLeft : mRight;
+  }
+
+  // Returns the value to apply on the right side.
+  const nsStyleTextOverflowSide& GetRight(PRUint8 aDirection) const {
+    NS_ASSERTION(aDirection == NS_STYLE_DIRECTION_LTR ||
+                 aDirection == NS_STYLE_DIRECTION_RTL, "bad direction");
+    return !mLogicalDirections || aDirection == NS_STYLE_DIRECTION_LTR ?
+             mRight : mLeft;
+  }
+
+  // Returns the first value that was specified.
+  const nsStyleTextOverflowSide* GetFirstValue() const {
+    return mLogicalDirections ? &mRight : &mLeft;
+  }
+
+  // Returns the second value, or null if there was only one value specified.
+  const nsStyleTextOverflowSide* GetSecondValue() const {
+    return mLogicalDirections ? nsnull : &mRight;
+  }
+
+  nsStyleTextOverflowSide mLeft;  // start side when mLogicalDirections is true
+  nsStyleTextOverflowSide mRight; // end side when mLogicalDirections is true
+  bool mLogicalDirections;  // true when only one value was specified
 };
 
 struct nsStyleTextReset {
   nsStyleTextReset(void);
   nsStyleTextReset(const nsStyleTextReset& aOther);
   ~nsStyleTextReset(void);
 
   void* operator new(size_t sz, nsPresContext* aContext) CPP_THROW_NEW {

--- a/layout/style/test/property_database.js
+++ b/layout/style/test/property_database.js
@@ -2563,18 +2563,18 @@ var gCSSProperties = {
 			"-moz-calc(3*25px + 50%)",
 		],
 		invalid_values: []
 	},
 	"text-overflow": {
 		domProp: "textOverflow",
 		inherited: false,
 		type: CSS_TYPE_LONGHAND,
-		initial_values: [ "clip", "clip clip" ],
-		other_values: [ "ellipsis", '""', "''", '"hello"', 'clip ellipsis', 'clip ""', '"hello" ""', '"" ellipsis' ],
+		initial_values: [ "clip" ],
+		other_values: [ "ellipsis", '""', "''", '"hello"', 'clip clip', 'ellipsis ellipsis', 'clip ellipsis', 'clip ""', '"hello" ""', '"" ellipsis' ],
 		invalid_values: [ "none", "auto", '"hello" inherit', 'inherit "hello"', 'clip initial', 'initial clip', 'initial inherit', 'inherit initial', 'inherit none']
 	},
 	"text-shadow": {
 		domProp: "textShadow",
 		inherited: true,
 		type: CSS_TYPE_LONGHAND,
 		prerequisites: { "color": "blue" },
 		initial_values: [ "none" ],