Updated spec for new tab behavior.

This change will need to be ported to CommonMark if we
do this.

We no longer replace spaces with tabs.

Rather, we treat tabs as equivalent spaces for purposes
of determining structure.  Tab stop is still 4.

Tabs in the text remain in the text.

1 files changed, 38 insertions, 7 deletions

diff --git a/test/spec.txt b/test/spec.txt
index f6ea793..0c42aae 100644
--- a/test/spec.txt
+++ b/test/spec.txt
@@ -249,15 +249,24 @@ A [punctuation character](@punctuation-character) is an [ASCII
 punctuation character] or anything in
 the unicode classes `Pc`, `Pd`, `Pe`, `Pf`, `Pi`, `Po`, or `Ps`.
 
-## Preprocessing
+## Tabs
 
-Tabs in lines are immediately expanded to [spaces][space], with a tab
-stop of 4 characters:
+Tabs in lines are not expanded to [spaces][space].  However,
+in contexts where indentation is significant for the
+document's structure, tabs behave as if they were replaced
+by spaces with a tab stop of 4 characters.
 
 .
 →foo→baz→→bim
 .
-<pre><code>foo baz     bim
+<pre><code>foo→baz→→bim
+</code></pre>
+.
+
+.
+  →foo→baz→→bim
+.
+<pre><code>foo→baz→→bim
 </code></pre>
 .
 
@@ -265,11 +274,33 @@ stop of 4 characters:
     a→a
     ὐ→a
 .
-<pre><code>a   a
-ὐ   a
+<pre><code>a→a
+ὐ→a
 </code></pre>
 .
 
+.
+  - foo
+
+→bar
+.
+<ul>
+<li>
+<p>foo</p>
+<p>bar</p>
+</li>
+</ul>
+.
+
+.
+>→foo→bar
+.
+<blockquote>
+<p>foo→bar</p>
+</blockquote>
+.
+
+
 ## Insecure characters
 
 For security reasons, the Unicode character `U+0000` must be replaced
@@ -4251,7 +4282,7 @@ backslashes:
 .
 \→\A\a\ \3\φ\«
 .
-<p>\   \A\a\ \3\φ\«</p>
+<p>\→\A\a\ \3\φ\«</p>
 .
 
 Escaped characters are treated as regular characters and do