[css-grid-1] Clarify that if neither min or max track sizing function is definite, you only get one repetition. (Reps never depend on intrinsic sizes.) w3c#4480

Author: tabatkins

css-grid-1/Overview.bs

@@ -1786,20 +1786,25 @@ Syntax of ''repeat()''</h5>
 Repeat-to-fill: ''auto-fill'' and ''auto-fit'' repetitions</h5>
 
 	When <dfn value for="repeat()">auto-fill</dfn> is given as the repetition number,
-	if the <a>grid container</a> has a <a>definite</a> size or max size in the relevant axis,
+	if the <a>grid container</a> has a <a>definite</a> [=preferred size=] or [=maximum size=] in the relevant axis,
 	then the number of repetitions is the largest possible positive integer
 	that does not cause the <a>grid</a> to overflow
 	the <a>content box</a> of its <a>grid container</a>
-	(treating each track as its <a>max track sizing function</a> if that is <a>definite</a>
-	or as its minimum track sizing function otherwise,
-	flooring the <a>max track sizing function</a> by the <a>min track sizing function</a> if both are <a>definite</a>,
-	and taking 'gap' into account);
+	taking 'gap' into account;
 	if any number of repetitions would overflow,
 	then 1 repetition.
-	Otherwise, if the <a>grid container</a> has a <a>definite</a> min size in the relevant axis,
+	Otherwise, if the <a>grid container</a> has a <a>definite</a> [=minimum size=] in the relevant axis,
 	the number of repetitions is the smallest possible positive integer that fulfills that minimum requirement.
 	Otherwise, the specified <a>track list</a> repeats only once.
 
+	For this purpose,
+	each track is treated as its <a>max track sizing function</a> if that is <a>definite</a>
+	or else its [=minimum track sizing function=] if that is definite.
+	If both are definite, floor the <a>max track sizing function</a>
+	by the <a>min track sizing function</a>.
+	If neither are definite,
+	the number of repetitions is one.
+
 	<div class="example">
 		For example, the following code will create
 		as many 25-character columns as will fit into the window width.