Index: src/wp-includes/template.php
===================================================================
--- src/wp-includes/template.php	(revision 38382)
+++ src/wp-includes/template.php	(working copy)
@@ -175,6 +175,12 @@
 	$templates = array();
 
 	if ( ! empty( $category->slug ) ) {
+
+		$slug_decoded = urldecode( $category->slug );
+		if ( $slug_decoded !== $category->slug ) {
+			$templates[] = "category-{$slug_decoded}.php";
+		}
+
 		$templates[] = "category-{$category->slug}.php";
 		$templates[] = "category-{$category->term_id}.php";
 	}
@@ -205,6 +211,12 @@
 	$templates = array();
 
 	if ( ! empty( $tag->slug ) ) {
+
+		$slug_decoded = urldecode( $tag->slug );
+		if ( $slug_decoded !== $tag->slug ) {
+			$templates[] = "tag-{$slug_decoded}.php";
+		}
+
 		$templates[] = "tag-{$tag->slug}.php";
 		$templates[] = "tag-{$tag->term_id}.php";
 	}
@@ -241,6 +253,12 @@
 
 	if ( ! empty( $term->slug ) ) {
 		$taxonomy = $term->taxonomy;
+
+		$slug_decoded = urldecode( $term->slug );
+		if ( $slug_decoded !== $term->slug ) {
+			$templates[] = "taxonomy-$taxonomy-{$slug_decoded}.php";
+		}
+
 		$templates[] = "taxonomy-$taxonomy-{$term->slug}.php";
 		$templates[] = "taxonomy-$taxonomy.php";
 	}
@@ -335,8 +353,13 @@
 	$templates = array();
 	if ( $template && 0 === validate_file( $template ) )
 		$templates[] = $template;
-	if ( $pagename )
+	if ( $pagename ) {
+		$pagename_decoded = urldecode( $pagename );
+		if ( $pagename_decoded !== $pagename ) {
+			$templates[] = "page-{$pagename_decoded}.php";
+		}
 		$templates[] = "page-$pagename.php";
+	}
 	if ( $id )
 		$templates[] = "page-$id.php";
 	$templates[] = 'page.php';
@@ -395,6 +418,12 @@
 	$templates = array();
 
 	if ( ! empty( $object->post_type ) ) {
+
+		$name_decoded = urldecode( $object->post_name );
+		if ( $name_decoded !== $object->post_name ) {
+			$templates[] = "single-{$object->post_type}-{$name_decoded}.php";
+		}
+
 		$templates[] = "single-{$object->post_type}-{$object->post_name}.php";
 		$templates[] = "single-{$object->post_type}.php";
 	}