8 files changed, 117 insertions, 2 deletions
diff --git a/src/select/computed.c b/src/select/computed.c
index 2efc8a7..23f7ea4 100644
--- a/src/select/computed.c
+++ b/src/select/computed.c
@@ -632,6 +632,11 @@ uint8_t css_computed_border_left_color(const css_computed_style *style,
 	return get_border_left_color(style, color);
 }
 
+uint8_t css_computed_box_sizing(const css_computed_style *style)
+{
+	return get_box_sizing(style);
+}
+
 uint8_t css_computed_height(const css_computed_style *style,
 		css_fixed *length, css_unit *unit)
 {
diff --git a/src/select/computed.h b/src/select/computed.h
index f77bda2..d2301f5 100644
--- a/src/select/computed.h
+++ b/src/select/computed.h
@@ -159,8 +159,9 @@ struct css_computed_style_i {
  * unicode_bidi			  2
  * visibility			  2
  * white_space			  3
+ * box_sizing			  2
  *				---
- *				 84 bits
+ *				 86 bits
  *
  * Colours are 32bits of AARRGGBB
  * Dimensions are encoded as a fixed point value + 4 bits of unit data
@@ -250,7 +251,7 @@ struct css_computed_style_i {
  * 21 mmmmmccc	min-width           | clear
  * 22 tttttxxx	padding-top         | overflow-x
  * 23 rrrrrppp	padding-right       | position
- * 24 bbbbbo..	padding-bottom      | opacity               | <unused>
+ * 24 bbbbboss	padding-bottom      | opacity               | box-sizing
  * 25 lllllttt	padding-left        | text-transform
  * 26 tttttwww	text-indent         | white-space
  * 27 bbbbbbbb	background-position
diff --git a/src/select/dispatch.c b/src/select/dispatch.c
index 326da58..7af9000 100644
--- a/src/select/dispatch.c
+++ b/src/select/dispatch.c
@@ -582,5 +582,10 @@ struct prop_table prop_dispatch[CSS_N_PROPERTIES] = {
 		PROPERTY_FUNCS(overflow_y),
 		0,
 		GROUP_NORMAL
+	},
+	{
+		PROPERTY_FUNCS(box_sizing),
+		0,
+		GROUP_NORMAL
 	}
 };
diff --git a/src/select/properties/Makefile b/src/select/properties/Makefile
index ce3ddfa..288eda9 100644
--- a/src/select/properties/Makefile
+++ b/src/select/properties/Makefile
@@ -21,6 +21,7 @@ border_top_color.c \
 border_top_style.c \
 border_top_width.c \
 bottom.c \
+box_sizing.c \
 break_after.c \
 break_before.c \
 break_inside.c \
diff --git a/src/select/properties/box_sizing.c b/src/select/properties/box_sizing.c
new file mode 100644
index 0000000..91c475d
--- /dev/null
+++ b/src/select/properties/box_sizing.c
@@ -0,0 +1,67 @@
+/*
+ * This file is part of LibCSS
+ * Licensed under the MIT License,
+ *		  http://www.opensource.org/licenses/mit-license.php
+ * Copyright 2017 Michael Drake <tlsa@netsurf-browser.org>
+ */
+
+#include "bytecode/bytecode.h"
+#include "bytecode/opcodes.h"
+#include "select/propset.h"
+#include "select/propget.h"
+#include "utils/utils.h"
+
+#include "select/properties/properties.h"
+#include "select/properties/helpers.h"
+
+css_error css__cascade_box_sizing(uint32_t opv, css_style *style, 
+		css_select_state *state)
+{
+	uint16_t value = CSS_BOX_SIZING_INHERIT;
+
+	UNUSED(style);
+
+	if (isInherit(opv) == false) {
+		switch (getValue(opv)) {
+		case BOX_SIZING_CONTENT_BOX:
+			value = CSS_BOX_SIZING_CONTENT_BOX;
+			break;
+		case BOX_SIZING_BORDER_BOX:
+			value = CSS_BOX_SIZING_BORDER_BOX;
+			break;
+		}
+	}
+
+	if (css__outranks_existing(getOpcode(opv), isImportant(opv), state,
+			isInherit(opv))) {
+		return set_box_sizing(state->computed, value);
+	}
+
+	return CSS_OK;
+}
+
+css_error css__set_box_sizing_from_hint(const css_hint *hint,
+		css_computed_style *style)
+{
+	return set_box_sizing(style, hint->status);
+}
+
+css_error css__initial_box_sizing(css_select_state *state)
+{
+	return set_box_sizing(state->computed, CSS_BOX_SIZING_CONTENT_BOX);
+}
+
+css_error css__compose_box_sizing(
+		const css_computed_style *parent,
+		const css_computed_style *child,
+		css_computed_style *result)
+{
+	uint8_t type = get_box_sizing(child);
+
+	if (type == CSS_BOX_SIZING_INHERIT) {
+		type = get_box_sizing(parent);
+	}
+
+	return set_box_sizing(result, type);
+}
+
diff --git a/src/select/properties/properties.h b/src/select/properties/properties.h
index f0ab29d..a1ab49f 100644
--- a/src/select/properties/properties.h
+++ b/src/select/properties/properties.h
@@ -42,6 +42,7 @@ PROPERTY_FUNCS(border_right_width);
 PROPERTY_FUNCS(border_bottom_width);
 PROPERTY_FUNCS(border_left_width);
 PROPERTY_FUNCS(bottom);
+PROPERTY_FUNCS(box_sizing);
 PROPERTY_FUNCS(break_after);
 PROPERTY_FUNCS(break_before);
 PROPERTY_FUNCS(break_inside);
diff --git a/src/select/propget.h b/src/select/propget.h
index 5552e39..6719443 100644
--- a/src/select/propget.h
+++ b/src/select/propget.h
@@ -1268,6 +1268,23 @@ static inline uint8_t get_background_attachment(
 #undef BACKGROUND_ATTACHMENT_SHIFT
 #undef BACKGROUND_ATTACHMENT_INDEX
 
+#define BOX_SIZING_INDEX 34
+#define BOX_SIZING_SHIFT 0
+#define BOX_SIZING_MASK  0x3
+static inline uint8_t get_box_sizing(
+		const css_computed_style *style)
+{
+	uint8_t bits = style->i.bits[BOX_SIZING_INDEX];
+	bits &= BOX_SIZING_MASK;
+	bits >>= BOX_SIZING_SHIFT;
+
+	/* 2bits: type */
+	return bits;
+}
+#undef BOX_SIZING_MASK
+#undef BOX_SIZING_SHIFT
+#undef BOX_SIZING_INDEX
+
 #define BORDER_COLLAPSE_INDEX 13
 #define BORDER_COLLAPSE_SHIFT 0
 #define BORDER_COLLAPSE_MASK  0x3
diff --git a/src/select/propset.h b/src/select/propset.h
index 76e4fe6..3f4038c 100644
--- a/src/select/propset.h
+++ b/src/select/propset.h
@@ -1361,6 +1361,24 @@ static inline css_error set_background_attachment(
 #undef BACKGROUND_ATTACHMENT_SHIFT
 #undef BACKGROUND_ATTACHMENT_INDEX
 
+#define BOX_SIZING_INDEX 34
+#define BOX_SIZING_SHIFT 0
+#define BOX_SIZING_MASK  0x3
+static inline css_error set_box_sizing(
+		css_computed_style *style, uint8_t type)
+{
+	uint8_t *bits = &style->i.bits[BOX_SIZING_INDEX];
+
+	/* 2bits: type */
+	*bits = (*bits & ~BOX_SIZING_MASK) |
+			((type & 0x3) << BOX_SIZING_SHIFT);
+
+	return CSS_OK;
+}
+#undef BOX_SIZING_MASK
+#undef BOX_SIZING_SHIFT
+#undef BOX_SIZING_INDEX
+
 #define BORDER_COLLAPSE_INDEX 13
 #define BORDER_COLLAPSE_SHIFT 0
 #define BORDER_COLLAPSE_MASK  0x3