Standardize special behavior of colspan/rowspan

ayg · zcorpan · commit 4fbd00f5c5a8 · 2017-04-26T16:28:48.000+02:00
Fixes whatwg#1198. Browsers all behave differently here, the spec matches none. The basic behavior selected was that of Chrome, except for very high values where we don't spec its overflow behavior. The colspan limit of 1000 matches Firefox/Edge (Firefox is not willing to raise its limit), instead of higher limits of 8190 in Chrome or more in WebKit. The rowspan limit of 65534 matches Firefox and Chrome, as opposed to 65535 in Edge or 8190 in WebKit. For setting, I followed Firefox because it's the simplest. Chrome converts negative numbers to 0, and Edge throws in some cases and clamps in others. Tests: whatwg#1993
diff --git a/source b/source
@@ -6989,6 +6989,16 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
   the number as a <span>valid non-negative integer</span> and that string must be used as the new
   content attribute value.</p> <!-- see previous paragraph for note about the weird range -->
 
+  <p>If a reflecting IDL attribute has an unsigned integer type (<code
+  data-x="idl-unsigned-long">unsigned long</code>) that is <dfn>clamped to the range</dfn>
+  [<var>min</var>, <var>max</var>], then on getting, the content attribute must first be parsed
+  according to the <span>rules for parsing non-negative integers</span>, and if that is successful,
+  and the value is between <var>min</var> and <var>max</var> inclusive, the resulting value must be
+  returned. If it fails, the default value must be returned. If it succeeds but the value is less
+  than <var>min</var>, <var>min</var> must be returned. If it succeeds but the value is greater than
+  <var>max</var>, <var>max</var> must be returned. On setting, it behaves the same as setting a
+  regular reflected unsigned integer.</p>
+
   <p>If a reflecting IDL attribute has a floating-point number type (<code
   data-x="idl-double">double</code> or <code data-x="idl-unrestricted-double">unrestricted
   double</code>), then, on getting, the content attribute must be parsed according to the
@@ -40217,10 +40227,11 @@ interface <dfn>HTMLTableCellElement</dfn> : <span>HTMLElement</span> {
   <h4>Attributes common to <code>td</code> and <code>th</code> elements</h4>
 
   <p>The <code>td</code> and <code>th</code> elements may have a <dfn><code data-x="attr-tdth-colspan">colspan</code></dfn> content attribute specified, whose value must
-  be a <span>valid non-negative integer</span> greater than zero.</p>
+  be a <span>valid non-negative integer</span> greater than zero and less than or equal to 1000.</p>
 
   <p>The <code>td</code> and <code>th</code> elements may also have a <dfn><code data-x="attr-tdth-rowspan">rowspan</code></dfn> content attribute specified, whose value must
-  be a <span>valid non-negative integer</span>. For this attribute, the value zero means that the
+  be a <span>valid non-negative integer</span> less than or equal to 65534.
+  For this attribute, the value zero means that the
   cell is to span all the remaining rows in the row group.</p> <!-- only in no-quirks and
   limited-quirks mode though, for back compat! -->
 
@@ -40279,18 +40290,20 @@ interface <dfn>HTMLTableCellElement</dfn> : <span>HTMLElement</span> {
 
   <div w-nodev>
 
-  <p>The <dfn><code data-x="dom-tdth-colSpan">colSpan</code></dfn> IDL attribute must
-  <span>reflect</span> the <code data-x="attr-tdth-colspan">colspan</code> content attribute. Its
-  default value is 1.</p>
-
   <!--
    https://software.hixie.ch/utilities/js/live-dom-viewer/?saved=1699
    https://software.hixie.ch/utilities/js/live-dom-viewer/?saved=1700
   -->
 
+  <!-- For colSpan/rowSpan rationale: https://github.com/whatwg/html/issues/1198 -->
+
+  <p>The <dfn><code data-x="dom-tdth-colSpan">colSpan</code></dfn> IDL attribute must
+  <span>reflect</span> the <code data-x="attr-tdth-colspan">colspan</code> content attribute. It is
+  <span>clamped to the range</span> [1, 1000], and its default value is 1.</p>
+
   <p>The <dfn><code data-x="dom-tdth-rowSpan">rowSpan</code></dfn> IDL attribute must
-  <span>reflect</span> the <code data-x="attr-tdth-rowspan">rowspan</code> content attribute. Its
-  default value is 1.</p>
+  <span>reflect</span> the <code data-x="attr-tdth-rowspan">rowspan</code> content attribute. It is
+  <span>clamped to the range</span> [0, 65534], and its default value is 1.</p>
 
   <p>The <dfn><code data-x="dom-tdth-headers">headers</code></dfn> IDL attribute must
   <span>reflect</span> the content attribute of the same name.</p>
@@ -40847,6 +40860,8 @@ interface <dfn>HTMLTableCellElement</dfn> : <span>HTMLElement</span> {
 
     <p>If parsing that value failed, or returned zero, or if the attribute is absent, then let <var>colspan</var> be 1, instead.</p>
 
+    <p>If <var>colspan</var> is greater than 1000, let it be 1000 instead.</p>
+
    </li>
 
    <li>
@@ -40857,6 +40872,8 @@ interface <dfn>HTMLTableCellElement</dfn> : <span>HTMLElement</span> {
 
     <p>If parsing that value failed or if the attribute is absent, then let <var>rowspan</var> be 1, instead.</p>
 
+    <p>If <var>rowspan</var> is greater than 65534, let it be 65534 instead.</p>
+
    </li>
 
    <li>
