[css-device-adapt] Implemented spec changes.

Source/core/dom/ViewportArguments.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
@@ skipping 122 matching lines @@
         switch (int(resultMaxHeight)) {
         case ViewportArguments::ValueDeviceWidth:
             resultMaxHeight = deviceSize.width();
             break;
         case ViewportArguments::ValueDeviceHeight:
             resultMaxHeight = deviceSize.height();
             break;
         }
 
         if (resultMinWidth != ViewportArguments::ValueAuto || resultMaxWidth != ViewportArguments::ValueAuto)
-            resultWidth = compareIgnoringAuto(resultMinWidth, compareIgnoringAuto(resultMaxWidth, deviceSize.width(), min), max);
+            resultWidth = compareIgnoringAuto(resultMinWidth, compareIgnoringAuto(resultMaxWidth, initialViewportSize.width(), min), max);
 
         if (resultMinHeight != ViewportArguments::ValueAuto || resultMaxHeight != ViewportArguments::ValueAuto)
-            resultHeight = compareIgnoringAuto(resultMinHeight, compareIgnoringAuto(resultMaxHeight, deviceSize.height(), min), max);
+            resultHeight = compareIgnoringAuto(resultMinHeight, compareIgnoringAuto(resultMaxHeight, initialViewportSize.height(), min), max);
 
         if (resultMinZoom != ViewportArguments::ValueAuto && resultMaxZoom != ViewportArguments::ValueAuto)
             resultMaxZoom = max(resultMinZoom, resultMaxZoom);
 
         if (resultZoom != ViewportArguments::ValueAuto)
             resultZoom = compareIgnoringAuto(resultMinZoom, compareIgnoringAuto(resultMaxZoom, resultZoom, min), max);
 
-        if (resultWidth == ViewportArguments::ValueAuto && resultZoom == ViewportArguments::ValueAuto)
-            resultWidth = deviceSize.width();
-
-        if (resultWidth == ViewportArguments::ValueAuto && resultHeight == ViewportArguments::ValueAuto)
-            resultWidth = deviceSize.width() / resultZoom;
+        if (resultWidth == ViewportArguments::ValueAuto && (resultHeight == ViewportArguments::ValueAuto || !initialViewportSize.height()))
+            resultWidth = initialViewportSize.width();
 
         if (resultWidth == ViewportArguments::ValueAuto)
-            resultWidth = resultHeight * deviceSize.width() / deviceSize.height();
+            resultWidth = resultHeight * initialViewportSize.width() / initialViewportSize.height();

[kenneth.r.christiansen, 2013/06/13 13:46:42]

I am a bit afraid that  this might break Android, as initialViewportSize depends
on orientation, where as deviceSize is always given portrait mode.

[Peter Beverloo, 2013/06/28 01:13:51]

Can you please add an ASSERT() to ensure that initialViewportSize.height() > 0? 
The current non-testing code path ensures this elsewhere, but if I have the
following line in a layout test it could cause a divide-by-zero:

internals.configurationForViewport(document, 1, 0, 0, 0, 0);

[rune, 2013/07/03 08:01:52]

Added.
It's ensured also for the configurationForViewport in the if-clause right above,
but it's not that obvious so an ASSERT is warranted.

 
-        if (resultHeight == ViewportArguments::ValueAuto)
-            resultHeight = resultWidth * deviceSize.height() / deviceSize.width();
-
-        if (resultZoom != ViewportArguments::ValueAuto || resultMaxZoom != ViewportArguments::ValueAuto) {
-            resultWidth = compareIgnoringAuto(resultWidth, deviceSize.width() / compareIgnoringAuto(resultZoom, resultMaxZoom, min), max);
-            resultHeight = compareIgnoringAuto(resultHeight, deviceSize.height() / compareIgnoringAuto(resultZoom, resultMaxZoom, min), max);
+        if (resultHeight == ViewportArguments::ValueAuto) {
+            if (!initialViewportSize.width())
+                resultHeight = initialViewportSize.height();
+            else
+                resultHeight = resultWidth * initialViewportSize.height() / initialViewportSize.width();
         }
-
-        resultWidth = max<float>(1, resultWidth);
-        resultHeight = max<float>(1, resultHeight);
     }
 
     if (type != ViewportArguments::CSSDeviceAdaptation && type != ViewportArguments::Implicit) {
         // Clamp values to a valid range, but not for @viewport since is
         // not mandated by the specification.
         resultWidth = clampLengthValue(resultWidth);
         resultHeight = clampLengthValue(resultHeight);
         resultZoom = clampScaleValue(resultZoom);
         resultMinZoom = clampScaleValue(resultMinZoom);
         resultMaxZoom = clampScaleValue(resultMaxZoom);
@@ skipping 11 matching lines @@
         result.maximumScale = float(5.0);
         result.minimumScale = min(float(5.0), result.minimumScale);
     } else
         result.maximumScale = resultMaxZoom;
     result.maximumScale = max(result.minimumScale, result.maximumScale);
 
     // Resolve initial-scale value.
     result.initialScale = resultZoom;
     if (resultZoom == ViewportArguments::ValueAuto) {
         result.initialScale = initialViewportSize.width() / defaultWidth;
-        if (resultWidth != ViewportArguments::ValueAuto)
+        if (resultWidth != ViewportArguments::ValueAuto && resultWidth > 0)
             result.initialScale = initialViewportSize.width() / resultWidth;
-        if (resultHeight != ViewportArguments::ValueAuto) {
+        if (resultHeight != ViewportArguments::ValueAuto && resultHeight > 0) {
             // if 'auto', the initial-scale will be negative here and thus ignored.
             result.initialScale = max<float>(result.initialScale, initialViewportSize.height() / resultHeight);
         }
     }
 
     // Constrain initial-scale value to minimum-scale/maximum-scale range.
     result.initialScale = min(result.maximumScale, max(result.minimumScale, result.initialScale));
 
     // Resolve width value.
     if (resultWidth == ViewportArguments::ValueAuto) {
@@ skipping 206 matching lines @@
         message.replace("%replacement2", replacement2);
 
     if ((errorCode == UnrecognizedViewportArgumentValueError || errorCode == TruncatedViewportArgumentValueError) && replacement1.find(';') != WTF::notFound)
         message.append(" Note that ';' is not a separator in viewport values. The list should be comma-separated.");
 
     // FIXME: This message should be moved off the console once a solution to https://bugs.webkit.org/show_bug.cgi?id=103274 exists.
     document->addConsoleMessage(RenderingMessageSource, viewportErrorMessageLevel(errorCode), message);
 }
 
 } // namespace WebCore