[css-sizing-3] Handle input intrinsic size minimum as a UA-imposed value, per fremy's comment in #2141 (comment) ; additional wording cleanup. #2141

Author: fantasai

css-sizing-3/Overview.bs

@@ -802,17 +802,20 @@ Intrinsic Sizes</h3>
 	The content in this case is defined to be the input control's values
 	(the <l spec=html>[=raw value=]</l> in the case of <{textarea}>,
 	or the <a href="https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#concept-fe-value">value</a> in the case of <{input}>),
-	possibly transformed to a localized display format,
+	possibly transformed to a more human-readable and/or localized display format,
 	which is then treated as child <a>text runs</a> of the input control.
-	If the input control has <a>placeholder text</a> overlaid,
+	If the input control has designated placeholder text
+	to be overlaid in its value display area,
 	then that text is also measured for the purpose of calculating the content-based size--
 	whether or not the placeholder text is visible at the moment.
 	(Thus the content-based intrinsic size of the input control
 	is the larger of the size to fit the placeholder text and the size to fit the value.)
-
-	Issue: So that this gives sensible results,
-	ensure minimum height via UA style sheet
-	<code>textarea { min-height: 1lh; }</code>.
+	The UA may enforce a minimum
+	(such as the size required to contain a single zero-width character)
+	on the form control’s
+	<a lt="min-content size">min-content</a> and <a>max-content sizes</a>
+	to ensure sufficient space for the caret
+	and otherwise maintain usability of the form control.
 
 	Issue: <code>&lt;input type=text></code> only ever displays its value on a single line.
 	This appears to be accomplished by "magic":
@@ -821,10 +824,12 @@ Intrinsic Sizes</h3>
 	rather than the 'white-space' property in the UA stylesheet.
 	Thus, the ''width/min-content'' size should probably automatically treat it as if it had ''white-space: pre''.
 
-	Note: See <a href="https://github.com/w3c/csswg-drafts/issues/1771">discussion about this functionality</a>.
-	This might be extended to <{iframe}> or other content-containing replaced elements,
-	but text inputs are the major use-case
-	and have the least additional complications.
+	Note:
+	This might be extended to <{iframe}> or other content-containing replaced elements
+	(see <a href="https://github.com/w3c/csswg-drafts/issues/1771">discussion</a>),
+	but text inputs are a major use-case,
+	and being document-internal,
+	have the least additional complications.
 
 <h3 id="intrinsic-contribution">
 Intrinsic Contributions</h3>