From f00ad20a6f75845b4e4182cf0f176a85d7c78d4f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Mudr=C3=A1k?= <david@moodle.com>
Date: Wed, 16 Dec 2020 20:50:06 +0100
Subject: [PATCH] MDL-70486 output: Improve check for block region name string
 existence

* The fact that non-existing strings are returned in certain format
  starting with the bracket, is kind of side debugging effect. The value
  is really undefined and should not be relied upon.
* The string could actually exist and be worded so that its first
  character is also the square bracket.
---
 lib/outputlib.php               | 20 ++++++++++----------
 lib/tests/theme_config_test.php | 12 ++++++++++++
 2 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/lib/outputlib.php b/lib/outputlib.php
index 9f533ca84d4..bfc93a0d6cc 100644
--- a/lib/outputlib.php
+++ b/lib/outputlib.php
@@ -2451,22 +2451,22 @@ class theme_config {
      * @return string
      */
     protected function get_region_name($region, $theme) {
-        $regionstring = get_string('region-' . $region, 'theme_' . $theme);
-        // A name exists in this theme, so use it
-        if (substr($regionstring, 0, 1) != '[') {
-            return $regionstring;
+
+        $stringman = get_string_manager();
+
+        // Check if the name is defined in the theme.
+        if ($stringman->string_exists('region-' . $region, 'theme_' . $theme)) {
+            return get_string('region-' . $region, 'theme_' . $theme);
         }
 
-        // Otherwise, try to find one elsewhere
-        // Check parents, if any
+        // Check the theme parents.
         foreach ($this->parents as $parentthemename) {
-            $regionstring = get_string('region-' . $region, 'theme_' . $parentthemename);
-            if (substr($regionstring, 0, 1) != '[') {
-                return $regionstring;
+            if ($stringman->string_exists('region-' . $region, 'theme_' . $parentthemename)) {
+                return get_string('region-' . $region, 'theme_' . $parentthemename);
             }
         }
 
-        // Last resort, try the boost theme for names
+        // Last resort, try the boost theme for names.
         return get_string('region-' . $region, 'theme_boost');
     }
 
diff --git a/lib/tests/theme_config_test.php b/lib/tests/theme_config_test.php
index 35f3df73c63..3308d079cfd 100644
--- a/lib/tests/theme_config_test.php
+++ b/lib/tests/theme_config_test.php
@@ -213,4 +213,16 @@ class core_theme_config_testcase extends advanced_testcase {
 
         $this->assertEquals($cssexpected, $cssactual);
     }
+
+    /**
+     * Test that {@see theme_config::get_all_block_regions()} returns localised list of region names.
+     */
+    public function test_get_all_block_regions() {
+        $this->resetAfterTest();
+
+        $theme = theme_config::load(theme_config::DEFAULT_THEME);
+        $regions = $theme->get_all_block_regions();
+
+        $this->assertEquals('Right', $regions['side-pre']);
+    }
 }