Addresses problems with TOC generation

Not the best way, probably. At the end of the day, TOC and anchors
should be generated using the same code, but this module is kind of
convoluted, so I'm doing this manually. This should close #41 but also
help with Raku/doc#2245

lib/Pod/To/HTML.pm

@@ -61,7 +61,10 @@ sub unescape_html(Str $str) returns Str {
 }
 
 sub escape_id ($id) {
-    $id.trim.subst(/\s+/, '_', :g).subst('"', '"', :g);
+    $id.trim.subst(/\s+/, '_', :g)
+      .subst('"', '"', :g)
+      .subst(' ', '_', :g)
+      .subst(''', "'", :g);
 }
 
 multi visit(Nil, |a) {
@@ -209,36 +212,40 @@ sub do-metadata returns Str {
 
 #| Turns accumulated headings into a nested-C«<ol>» table of contents
 sub do-toc($pod) returns Str {
-  my @levels is default(0) = 0;
-  
-  my proto sub find-headings($node, :$inside-heading){*}
-  
-  multi sub find-headings(Str $s is raw, :$inside-heading){
-    $inside-heading ?? $s.trim.&escape_html !! ''
-  }
-  
-  multi sub find-headings(Pod::FormattingCode $node is raw where *.type eq 'C', :$inside-heading){
-    my $html = $node.contents.map(*.&find-headings(:$inside-heading));
-    $inside-heading ?? qq[<code class="pod-code-inline">{$html}</code>] !! ''
-  }
-  
-  multi sub find-headings(Pod::Heading $node is raw, :$inside-heading){
-        @levels.splice($node.level) if $node.level < +@levels;
-        @levels[$node.level-1]++;
+    my @levels is default(0) = 0;
+
+    my proto sub find-headings($node, :$inside-heading){*}
+
+    multi sub find-headings(Str $s is raw, :$inside-heading){
+      $inside-heading ?? $s.trim.&escape_html !! ''
+    }
+
+    multi sub find-headings(Pod::FormattingCode $node is raw where *.type eq 'C', :$inside-heading){
+      my $html = $node.contents.map(*.&find-headings(:$inside-heading));
+      $inside-heading ?? qq[<code class="pod-code-inline">{$html}</code>] !! ''
+    }
+
+    multi sub find-headings(Pod::Heading $node is raw, :$inside-heading) {
+      @levels.splice($node.level) if $node.level < +@levels;
+      @levels[$node.level-1]++;
         my $level-hierarchy = @levels.join('.'); # e.g. §4.2.12
         my $text = $node.contents.map(*.&find-headings(inside-heading => True));
         my $link = escape_id(node2text($node.contents));
         qq[<tr class="toc-level-{$node.level}"><td class="toc-number">{$level-hierarchy}</td><td class="toc-text"><a href="#$link">{$text}</a></td></tr>\n];
     }
+
     multi sub find-headings(Positional \list, :$inside-heading){
         list.map(*.&find-headings(:$inside-heading))
     }
+
     multi sub find-headings(Pod::Block $node is raw, :$inside-heading){
         $node.contents.map(*.&find-headings(:$inside-heading))
     }
+
     multi sub find-headings(Pod::Config $node, :$inside-heading){
         ''
     }
+
     multi sub find-headings(Pod::Raw $node is raw, :$inside-heading){
         $node.contents.map(*.&find-headings(:$inside-heading))
     }

t/11-issue-41.t

@@ -0,0 +1,18 @@
+use Test;
+use Pod::To::HTML;
+plan 2;
+
+=begin pod
+=head2 Rendering Perl 6 with no-break space
+
+Nothing to see here
+
+=head2 What's wrong with this rendering?
+
+Nothing to see here either
+=end pod
+
+my $r = pod2html $=pod;
+
+ok $r ~~ m/\#What\'s_wrong/;
+ok $r ~~ m/\#Rendering_Perl_6/;