Sort sitemap elements by permalink

This feature was originally reported in #257 and got fixed in
3a2dab59743e8d193a80ddb1aa1932e1b5462322, however it seems this
got lost during development.

Closes #661
Ref #257

components/site/src/lib.rs

@@ -777,11 +777,15 @@ impl Site {
         ensure_directory_exists(&self.output_path)?;
 
         let library = self.library.read().unwrap();
-        let all_sitemap_entries = sitemap::find_entries(
-            &library,
-            &self.taxonomies[..],
-            &self.config,
-        );
+        let all_sitemap_entries = {
+            let mut all_sitemap_entries = sitemap::find_entries(
+                &library,
+                &self.taxonomies[..],
+                &self.config,
+            );
+            all_sitemap_entries.sort();
+            all_sitemap_entries
+        };
         let sitemap_limit = 30000;
 
         if all_sitemap_entries.len() < sitemap_limit {

components/site/src/sitemap.rs

@@ -5,6 +5,7 @@ use std::collections::{HashSet};
 use tera::{Map, Value};
 use config::{Config};
 use library::{Library, Taxonomy};
+use std::cmp::Ordering;
 
 /// The sitemap only needs links, potentially date and extra for pages in case of updates
 /// for examples so we trim down all entries to only that
@@ -39,6 +40,18 @@ impl<'a> SitemapEntry<'a> {
     }
 }
 
+impl<'a> PartialOrd for SitemapEntry<'a> {
+    fn partial_cmp(&self, other: &SitemapEntry) -> Option<Ordering> {
+        Some(self.permalink.as_ref().cmp(other.permalink.as_ref()))
+    }
+}
+
+impl<'a> Ord for SitemapEntry<'a> {
+    fn cmp(&self, other: &SitemapEntry) -> Ordering {
+        self.permalink.as_ref().cmp(other.permalink.as_ref())
+    }
+}
+
 /// Finds out all the links to put in a sitemap from the pages/sections/taxonomies
 /// There are no duplicate permalinks in the output vec
 pub fn find_entries<'a>(library: &'a Library, taxonomies: &'a [Taxonomy], config: &'a Config) -> Vec<SitemapEntry<'a>> {