trail: avoid collecting trail members twice

diff --git a/IkiWiki/Plugin/trail.pm b/IkiWiki/Plugin/trail.pm
index e9b4d9cd4fc589ff2b35f2256f6d7d76bd697770..e6e55bbdbe104364a407466bd16daf0d099246ba 100644 (file)
--- a/IkiWiki/Plugin/trail.pm
+++ b/IkiWiki/Plugin/trail.pm
@@ -88,6 +88,8 @@ sub needsbuild (@) {
        return $needsbuild;
 }
 
+my $scanned = 0;
+
 =for wiki
 
 The `trail` directive is supplied by the [[plugins/contrib/trail]]
@@ -112,6 +114,15 @@ The available options are:
 sub preprocess_trail (@) {
        my %params = @_;
 
+       # avoid collecting everything in the preprocess stage if we already
+       # did in the scan stage
+       if (defined wantarray) {
+               return "" if $scanned;
+       }
+       else {
+               $scanned = 1;
+       }
+
        if (exists $params{circular}) {
                $pagestate{$params{page}}{trail}{circular} =
                        IkiWiki::yesno($params{circular});
@@ -166,14 +177,20 @@ to the trail.
 =cut
 
 sub preprocess_trailinline (@) {
-       preprocess_trail(@_);
-       return unless defined wantarray;
+       my %params = @_;
+
+       if (defined wantarray) {
+               scalar preprocess_trail(%params);
 
-       if (IkiWiki->can("preprocess_inline")) {
-               return IkiWiki::preprocess_inline(@_);
+               if (IkiWiki->can("preprocess_inline")) {
+                       return IkiWiki::preprocess_inline(@_);
+               }
+               else {
+                       error("trailinline directive requires the inline plugin");
+               }
        }
        else {
-               error("trailinline directive requires the inline plugin");
+               preprocess_trail(%params);
        }
 }
 
@@ -193,6 +210,15 @@ sub preprocess_trailitem (@) {
        my $link = shift;
        shift;
 
+       # avoid collecting everything in the preprocess stage if we already
+       # did in the scan stage
+       if (defined wantarray) {
+               return "" if $scanned;
+       }
+       else {
+               $scanned = 1;
+       }
+
        my %params = @_;
        my $trail = $params{page};
 
@@ -242,7 +268,18 @@ sub preprocess_traillink (@) {
        $link = linkpage($2);
 
        add_link($params{page}, $link, 'trail');
-       push @{$pagestate{$params{page}}{trail}{contents}}, "link $link";
+
+       # avoid collecting everything in the preprocess stage if we already
+       # did in the scan stage
+       my $already;
+       if (defined wantarray) {
+               $already = $scanned;
+       }
+       else {
+               $scanned = 1;
+       }
+
+       push @{$pagestate{$params{page}}{trail}{contents}}, [link => $link] unless $already;
 
        if (defined $linktext) {
                $linktext = pagetitle($linktext);