attempt to define foolip's proposal

Author: annevk

fetch.bs

@@ -6074,8 +6074,6 @@ that RFC's normative processing requirements to be compatible with deployed cont
  <li><p>Let <var>mimeType</var> be the result of <a>collecting a sequence of code points</a> that
  are not equal to U+002C (,), given <var>position</var>.
 
- <li><p><a>Strip leading and trailing ASCII whitespace</a> from <var>mimeType</var>.
-
  <li><p>If <var>position</var> is past the end of <var>input</var>, then return failure.
 
  <li><p>Advance <var>position</var> by 1.
@@ -6085,8 +6083,9 @@ that RFC's normative processing requirements to be compatible with deployed cont
  <li><p>Let <var>body</var> be the <a>string percent decoding</a> of <var>encodedBody</var>.
 
  <li>
-  <p>If <var>mimeType</var> ends with an <a>ASCII case-insensitive</a> match for
-  "<code>;base64</code>", then:
+  <p>If <var>mimeType</var> ends with U+003B (;), followed by zero or more U+0020 SPACE, followed by
+  an <a>ASCII case-insensitive</a> match for "<code>base64</code>", followed by zero or more U+0020
+  SPACE, then:
 
   <ol>
    <li><p>Let <var>stringBody</var> be the <a>isomorphic decode</a> of <var>body</var>.
@@ -6095,7 +6094,13 @@ that RFC's normative processing requirements to be compatible with deployed cont
 
    <li><p>If <var>body</var> is failure, then return failure.
 
-   <li><p>Remove the last 7 code points from <var>mimeType</var>.
+   <li><p>Remove trailing U+0020 SPACE <a>code points</a> from <var>mimeType</var>, if any.
+
+   <li><p>Remove the last 6 <a>code points</a> from <var>mimeType</var>.
+
+   <li><p>Remove trailing U+0020 SPACE <a>code points</a> from <var>mimeType</var>, if any.
+
+   <li><p>Remove the last <a>code point</a> from <var>mimeType</var>.
   </ol>
 
  <li><p>If <var>mimeType</var> starts with "<code>;</code>", then prepend "<code>text/plain</code>"