INPUT textfield: Do not remove line-height of innerEditor if we don't need to remove it.

third_party/WebKit/Source/core/layout/LayoutTextControlSingleLine.cpp

 /**
  * Copyright (C) 2006, 2007, 2010 Apple Inc. All rights reserved.
  *           (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 255 matching lines @@
 PassRefPtr<ComputedStyle> LayoutTextControlSingleLine::createInnerEditorStyle(const ComputedStyle& startStyle) const
 {
     RefPtr<ComputedStyle> textBlockStyle = ComputedStyle::create();
     textBlockStyle->inheritFrom(startStyle);
     adjustInnerEditorStyle(*textBlockStyle);
 
     textBlockStyle->setWhiteSpace(PRE);
     textBlockStyle->setOverflowWrap(NormalOverflowWrap);
     textBlockStyle->setTextOverflow(textShouldBeTruncated() ? TextOverflowEllipsis : TextOverflowClip);
 
+    int computedLineHeight = lineHeight(true, HorizontalLine, PositionOfInteriorLineBoxes);
     // Do not allow line-height to be smaller than our default.
-    if (textBlockStyle->fontSize() >= lineHeight(true, HorizontalLine, PositionOfInteriorLineBoxes) || !startStyle.logicalHeight().isIntrinsicOrAuto())
+    if (textBlockStyle->fontSize() >= computedLineHeight)
+        textBlockStyle->setLineHeight(ComputedStyle::initialLineHeight());
+
+    // We'd like to remove line-height if it's unnecessary because
+    // overflow:scroll clips editing text by line-height.
+    Length logicalHeight = startStyle.logicalHeight();
+    // Here, we remove line-height if the INPUT fixed height is taller than the
+    // line-height.  It's not the precise condition because logicalHeight
+    // includes border and padding if box-sizing:border-box, and non-fixed
+    // heights are possible.
+    if (logicalHeight.isFixed() && logicalHeight.getFloatValue() > computedLineHeight)

[kojii, 2016/04/26 06:03:21]

Are Percent and Calculated converted to Fixed at this point? By changing
!isIntrinsicOrAuto() to isFixed(), these are left in between, correct?

[tkent, 2016/04/26 07:03:28]

No.  We are unable to determine if it's ok to remove line-height.  So, we'll see
the editing-text-cutting-issues again in percent/calculated height.

Another choice is to remove line-height if percent/calculated height. Like
   if (logicalHeight.hasPercent() || logicalHeight.isFixed() && ...)

[tkent, 2016/04/26 07:44:49]

We discussed offline, and agreed that we should not change the behavior in a
case of Percent/Calculated.  I have uploaded new patch set.

         textBlockStyle->setLineHeight(ComputedStyle::initialLineHeight());
 
     textBlockStyle->setDisplay(BLOCK);
     textBlockStyle->setUnique();
 
     if (inputElement()->shouldRevealPassword())
         textBlockStyle->setTextSecurity(TSNONE);
 
     textBlockStyle->setOverflowX(OverflowScroll);
+    // overflow-y:visible doesn't work because overflow-x:scroll makes a layer.
     textBlockStyle->setOverflowY(OverflowScroll);
     RefPtr<ComputedStyle> noScrollbarStyle = ComputedStyle::create();
     noScrollbarStyle->setStyleType(PseudoIdScrollbar);
     noScrollbarStyle->setDisplay(NONE);
     textBlockStyle->addCachedPseudoStyle(noScrollbarStyle);
     textBlockStyle->setHasPseudoStyle(PseudoIdScrollbar);
 
     return textBlockStyle.release();
 }
 
@@ skipping 65 matching lines @@
     // inner-editor element overflows the INPUT box intentionally, however it
     // shouldn't affect outside of the INPUT box.  So we ignore child overflow.
 }
 
 HTMLInputElement* LayoutTextControlSingleLine::inputElement() const
 {
     return toHTMLInputElement(node());
 }
 
 } // namespace blink