From 7d62bc241761053d1e4b60e4e928465c3e08573c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Mudr=C3=A1k?= <david@moodle.com>
Date: Tue, 15 Sep 2015 22:08:04 +0200
Subject: [PATCH] MDL-51403 install: Improve the language validation in the CLI
 installer

There are two essential improvements here. Firstly, by replacing the
file_exists() check with array_key_exists() we make sure that only
actual language code will be written into the config.php file (and not
the empty value in case of input that does not pass the PARAM_SAFEDIR
cleaning).

Additionally, we no longer display the full list of available languages
by default. The list can be displayed in the interactive mode by typing
the ? character instead of the language code. This makes the overall
interface cleaner, does not cause the header information (such as the
Moodle version) to scroll away and makes the nice cli logo more visible
(which was the main motivation for the whole patch anyway ;-).
---
 admin/cli/install.php | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/admin/cli/install.php b/admin/cli/install.php
index 131056d7e67..51364b9f149 100644
--- a/admin/cli/install.php
+++ b/admin/cli/install.php
@@ -273,7 +273,8 @@ $interactive = empty($options['non-interactive']);
 
 // set up language
 $lang = clean_param($options['lang'], PARAM_SAFEDIR);
-if (file_exists($CFG->dirroot.'/install/lang/'.$lang)) {
+$languages = get_string_manager()->get_list_of_translations();
+if (array_key_exists($lang, $languages)) {
     $CFG->lang = $lang;
 }
 
@@ -295,23 +296,34 @@ echo get_string('cliinstallheader', 'install', $CFG->target_release)."\n";
 //Fist select language
 if ($interactive) {
     cli_separator();
-    $languages = get_string_manager()->get_list_of_translations();
     // Do not put the langs into columns because it is not compatible with RTL.
-    $langlist = implode("\n", $languages);
     $default = $CFG->lang;
-    cli_heading(get_string('availablelangs', 'install'));
-    echo $langlist."\n";
+    cli_heading(get_string('chooselanguagehead', 'install'));
+    if (array_key_exists($default, $languages)) {
+        echo $default.' - '.$languages[$default]."\n";
+    }
+    if ($default !== 'en') {
+        echo 'en - English (en)'."\n";
+    }
+    echo '? - '.get_string('availablelangs', 'install')."\n";
     $prompt = get_string('clitypevaluedefault', 'admin', $CFG->lang);
     $error = '';
     do {
         echo $error;
         $input = cli_input($prompt, $default);
-        $input = clean_param($input, PARAM_SAFEDIR);
 
-        if (!file_exists($CFG->dirroot.'/install/lang/'.$input)) {
-            $error = get_string('cliincorrectvalueretry', 'admin')."\n";
+        if ($input === '?') {
+            echo implode("\n", $languages)."\n";
+            $error = "\n";
+
         } else {
-            $error = '';
+            $input = clean_param($input, PARAM_SAFEDIR);
+
+            if (!array_key_exists($input, $languages)) {
+                $error = get_string('cliincorrectvalueretry', 'admin')."\n";
+            } else {
+                $error = '';
+            }
         }
     } while ($error !== '');
     $CFG->lang = $input;