Canonicalize template directory before globbing.

This prevents the glob from returning paths that don't include the root
template dir due to resolution of relative paths like `./foo`,
preventing #1541 from reoccurring. Furthermore, this prevents
misconfigured, non-existent template directories from silently passing
through, instead causing an error at init-time.

contrib/lib/src/templates/context.rs

@@ -18,7 +18,15 @@ impl Context {
     /// Load all of the templates at `root`, initialize them using the relevant
     /// template engine, and store all of the initialized state in a `Context`
     /// structure, which is returned if all goes well.
-    pub fn initialize(root: PathBuf) -> Option<Context> {
+    pub fn initialize(root: &Path) -> Option<Context> {
+        let root = match root.canonicalize() {
+            Ok(root) => root,
+            Err(e) => {
+                error!("Invalid template directory '{}': {}.", root.display(), e);
+                return None;
+            }
+        };
+
         let mut templates: HashMap<String, TemplateInfo> = HashMap::new();
         for ext in Engines::ENABLED_EXTENSIONS {
             let mut glob_path = root.join("**").join("*");
@@ -48,13 +56,12 @@ impl Context {
         }
 
         Engines::init(&templates)
-            .map(|engines| Context { root, templates, engines } )
+            .map(|engines| Context { root: root.into(), templates, engines } )
     }
 }
 
 /// Removes the file path's extension or does nothing if there is none.
-fn remove_extension<P: AsRef<Path>>(path: P) -> PathBuf {
-    let path = path.as_ref();
+fn remove_extension(path: &Path) -> PathBuf {
     let stem = match path.file_stem() {
         Some(stem) => stem,
         None => return path.to_path_buf()

contrib/lib/src/templates/fairing.rs

@@ -103,7 +103,7 @@ mod context {
                 if changed {
                     info_!("Change detected: reloading templates.");
                     let mut ctxt = self.context_mut();
-                    if let Some(mut new_ctxt) = Context::initialize(ctxt.root.clone()) {
+                    if let Some(mut new_ctxt) = Context::initialize(&ctxt.root) {
                         match callback(&mut new_ctxt.engines) {
                             Ok(()) => *ctxt = new_ctxt,
                             Err(e) => {
@@ -164,8 +164,7 @@ impl Fairing for TemplateFairing {
             }
         };
 
-        let root = Source::from(&*path);
-        match Context::initialize(path) {
+        match Context::initialize(&path) {
             Some(mut ctxt) => {
                 use rocket::{logger::PaintExt, yansi::Paint};
                 use crate::templates::Engines;
@@ -174,7 +173,7 @@ impl Fairing for TemplateFairing {
 
                 match (self.callback)(&mut ctxt.engines) {
                     Ok(()) => {
-                        info_!("directory: {}", Paint::white(root));
+                        info_!("directory: {}", Paint::white(Source::from(&*path)));
                         info_!("engines: {:?}", Paint::white(Engines::ENABLED_EXTENSIONS));
                         Ok(rocket.manage(ContextManager::new(ctxt)))
                     }
@@ -185,7 +184,10 @@ impl Fairing for TemplateFairing {
                     }
                 }
             }
-            None => Err(rocket),
+            None => {
+                error_!("Launch will be aborted due to failed template initialization.");
+                Err(rocket)
+            }
         }
     }
 

contrib/lib/src/templates/mod.rs

@@ -352,7 +352,7 @@ impl Template {
     ///
     /// # Example
     ///
-    /// ```rust
+    /// ```rust,no_run
     /// # extern crate rocket;
     /// # extern crate rocket_contrib;
     /// use std::collections::HashMap;

site/guide/5-responses.md

@@ -399,10 +399,11 @@ fairings. To attach the template fairing, simply call
 
 # use rocket_contrib::templates::Template;
 
-fn main() {
+#[launch]
+fn rocket() -> _ {
     rocket::ignite()
         .mount("/", routes![/* .. */])
-        .attach(Template::fairing());
+        .attach(Template::fairing())
 }
 ```