From e22b18aabcb46e3c0eafeb466b51bb3eb18cf1e1 Mon Sep 17 00:00:00 2001
From: Joey Hess <joey@kitenet.net>
Date: Mon, 27 Sep 2010 15:47:14 -0400
Subject: [PATCH] template_depends: throw nice error message when template
 cannot be found

plovs reported a crash when templates were not installed properly,
with a non-useful error about the template object not being defined.
I've audited all uses of template_depends(), and template(), and it makes
sense for them to throw an error if the template cannot be found. All code
with a user-supplied template catches errors already, to handle template
parse failures.

It did not make sense for template_file to throw errors, as some code uses
it to probe if a template file is available.
---
 IkiWiki.pm                     | 8 +++++---
 IkiWiki/Plugin/edittemplate.pm | 3 ---
 IkiWiki/Plugin/inline.pm       | 5 +----
 IkiWiki/Plugin/template.pm     | 7 ++-----
 doc/plugins/write.mdwn         | 2 ++
 5 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/IkiWiki.pm b/IkiWiki.pm
index 6da281999..66ae86809 100644
--- a/IkiWiki.pm
+++ b/IkiWiki.pm
@@ -1769,12 +1769,14 @@ sub template_depends ($$;@) {
 	my $page=shift;
 	
 	my ($filename, $tpage, $untrusted)=template_file($name);
+	if (! defined $filename) {
+		error(sprintf(gettext("template %s not found"), $name))
+	}
+
 	if (defined $page && defined $tpage) {
 		add_depends($page, $tpage);
 	}
-
-	return unless defined $filename;
-
+	
 	my @opts=(
 		filter => sub {
 			my $text_ref = shift;
diff --git a/IkiWiki/Plugin/edittemplate.pm b/IkiWiki/Plugin/edittemplate.pm
index 4f07866e4..576c94be4 100644
--- a/IkiWiki/Plugin/edittemplate.pm
+++ b/IkiWiki/Plugin/edittemplate.pm
@@ -132,9 +132,6 @@ sub filltemplate ($$) {
 		# up a template that doesn't work.
 		return "[[!pagetemplate ".gettext("failed to process template:")." $@]]";
 	}
-	if (! defined $template) {
-		return;
-	}
 
 	$template->param(name => $page);
 
diff --git a/IkiWiki/Plugin/inline.pm b/IkiWiki/Plugin/inline.pm
index 715a3d652..c00aed299 100644
--- a/IkiWiki/Plugin/inline.pm
+++ b/IkiWiki/Plugin/inline.pm
@@ -336,10 +336,7 @@ sub preprocess_inline (@) {
 					blind_cache => 1);
 			};
 			if ($@) {
-				error gettext("failed to process template:")." $@";
-			}
-			if (! $template) {
-				error sprintf(gettext("template %s not found"), $params{template}.".tmpl");
+				error sprintf(gettext("failed to process template %s"), $params{template}.".tmpl").": $@";
 			}
 		}
 		my $needcontent=$raw || (!($archive && $quick) && $template->query(name => 'content'));
diff --git a/IkiWiki/Plugin/template.pm b/IkiWiki/Plugin/template.pm
index db26bfe31..3df06e652 100644
--- a/IkiWiki/Plugin/template.pm
+++ b/IkiWiki/Plugin/template.pm
@@ -41,12 +41,9 @@ sub preprocess (@) {
 			blind_cache => 1);
 	};
 	if ($@) {
-		error gettext("failed to process template:")." $@";
-	}
-	if (! $template) {
-		error sprintf(gettext("%s not found"),
+		error sprintf(gettext("failed to process template %s"),
 			htmllink($params{page}, $params{destpage},
-				"/templates/$params{id}"))
+				"/templates/$params{id}"))." $@";
 	}
 
 	$params{basename}=IkiWiki::basename($params{page});
diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index e60314485..d5bd1dd76 100644
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -740,6 +740,8 @@ with no ".tmpl" extension. Template pages are normally looked for in
 the templates/ directory. If the page name starts with "/", a page
 elsewhere in the wiki can be used.
 
+If the template is not found, or contains a syntax error, an error is thrown.
+
 ### `template_depends($$;@)`
 
 Use this instead of `template()` if the content of a template is being
-- 
2.26.2