Change behaviour of Alt text.

Source/core/rendering/RenderImage.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011-2012. All rights reserved.
  *
@@ skipping 275 matching lines @@
 
         if (cWidth > 2 && cHeight > 2) {
             const int borderWidth = 1;
 
             // Draw an outline rect where the image should be.
             context->setStrokeStyle(SolidStroke);
             context->setStrokeColor(Color::lightGray);
             context->setFillColor(Color::transparent);
             context->drawRect(pixelSnappedIntRect(LayoutRect(paintOffset.x() + leftBorder + leftPad, paintOffset.y() + topBorder + topPad, cWidth, cHeight)));
 
-            bool errorPictureDrawn = false;
-            LayoutSize imageOffset;
+            bool altTextDisplayed = false;
             // When calculating the usable dimensions, exclude the pixels of
             // the ouline rect so the error image/alt text doesn't draw on it.
             LayoutUnit usableWidth = cWidth - 2 * borderWidth;
             LayoutUnit usableHeight = cHeight - 2 * borderWidth;
 
             RefPtr<Image> image = m_imageResource->image();
 
-            if (m_imageResource->errorOccurred() && !image->isNull() && usableWidth >= image->width() && usableHeight >= image->height()) {
-                float deviceScaleFactor = WebCore::deviceScaleFactor(frame());
-                // Call brokenImage() explicitly to ensure we get the broken image icon at the appropriate resolution.
-                pair<Image*, float> brokenImageAndImageScaleFactor = ImageResource::brokenImage(deviceScaleFactor);
-                image = brokenImageAndImageScaleFactor.first;
-                IntSize imageSize = image->size();
-                imageSize.scale(1 / brokenImageAndImageScaleFactor.second);
-                // Center the error image, accounting for border and padding.
-                LayoutUnit centerX = (usableWidth - imageSize.width()) / 2;
-                if (centerX < 0)
-                    centerX = 0;
-                LayoutUnit centerY = (usableHeight - imageSize.height()) / 2;
-                if (centerY < 0)
-                    centerY = 0;
-                imageOffset = LayoutSize(leftBorder + leftPad + centerX + borderWidth, topBorder + topPad + centerY + borderWidth);
-                context->drawImage(image.get(), pixelSnappedIntRect(LayoutRect(paintOffset + imageOffset, imageSize)), CompositeSourceOver, shouldRespectImageOrientation());
-                errorPictureDrawn = true;
-            }
-
             if (!m_altText.isEmpty()) {
                 const Font& font = style()->font();
                 const FontMetrics& fontMetrics = font.fontMetrics();
                 LayoutUnit ascent = fontMetrics.ascent();
                 LayoutPoint textRectOrigin = paintOffset;
                 textRectOrigin.move(leftBorder + leftPad + (paddingWidth / 2) - borderWidth, topBorder + topPad + (paddingHeight / 2) - borderWidth);
                 LayoutPoint textOrigin(textRectOrigin.x(), textRectOrigin.y() + ascent);
 
                 // Only draw the alt text if it'll fit within the content box,
                 // and only if it fits above the error image.
                 TextRun textRun = RenderBlockFlow::constructTextRun(this, font, m_altText, style(), TextRun::AllowTrailingExpansion | TextRun::ForbidLeadingExpansion, DefaultTextRunFlags | RespectDirection);
                 float textWidth = font.width(textRun);
                 TextRunPaintInfo textRunPaintInfo(textRun);
                 textRunPaintInfo.bounds = FloatRect(textRectOrigin, FloatSize(textWidth, fontMetrics.height()));
                 context->setFillColor(resolveColor(CSSPropertyColor));
                 if (textRun.direction() == RTL) {
                     int availableWidth = cWidth - static_cast<int>(paddingWidth);
                     textOrigin.move(availableWidth - ceilf(textWidth), 0);
                 }
-                if (errorPictureDrawn) {
-                    if (usableWidth >= textWidth && fontMetrics.height() <= imageOffset.height())
-                        context->drawBidiText(font, textRunPaintInfo, textOrigin);
-                } else if (usableWidth >= textWidth && usableHeight >= fontMetrics.height()) {
+                if (usableWidth >= textWidth && usableHeight >= fontMetrics.height()) {
                     context->drawBidiText(font, textRunPaintInfo, textOrigin);
+                    altTextDisplayed = true;
                 }
             }
+
+            if (!altTextDisplayed && m_imageResource->errorOccurred() && !image->isNull() && usableWidth >= image->width() && usableHeight >= image->height()) {
+                float deviceScaleFactor = WebCore::deviceScaleFactor(frame());
+                // Call brokenImage() explicitly to ensure we get the broken image icon at the appropriate resolution.
+                pair<Image*, float> brokenImageAndImageScaleFactor = ImageResource::brokenImage(deviceScaleFactor);
+                image = brokenImageAndImageScaleFactor.first;
+                IntSize imageSize = image->size();
+                imageSize.scale(1 / brokenImageAndImageScaleFactor.second);
+                // Center the error image, accounting for border and padding.
+                LayoutUnit centerX = (usableWidth - imageSize.width()) / 2;
+                if (centerX < 0)
+                    centerX = 0;
+                LayoutUnit centerY = (usableHeight - imageSize.height()) / 2;
+                if (centerY < 0)
+                    centerY = 0;
+                LayoutSize imageOffset;
+                imageOffset = LayoutSize(leftBorder + leftPad + centerX + borderWidth, topBorder + topPad + centerY + borderWidth);
+                context->drawImage(image.get(), pixelSnappedIntRect(LayoutRect(paintOffset + imageOffset, imageSize)), CompositeSourceOver, shouldRespectImageOrientation());
+            }
         }
     } else if (m_imageResource->hasImage() && cWidth > 0 && cHeight > 0) {
         RefPtr<Image> img = m_imageResource->image(cWidth, cHeight);
         if (!img || img->isNull())
             return;
 
         LayoutRect contentRect = contentBoxRect();
         contentRect.moveBy(paintOffset);
         LayoutRect paintRect = replacedContentRect();
         paintRect.moveBy(paintOffset);
@@ skipping 261 matching lines @@
         return 0;
 
     ImageResource* cachedImage = m_imageResource->cachedImage();
     if (cachedImage && cachedImage->image() && cachedImage->image()->isSVGImage())
         return toSVGImage(cachedImage->image())->embeddedContentBox();
 
     return 0;
 }
 
 } // namespace WebCore