bug #10899 Explicitly define the encoding. (jakzal)

This PR was merged into the 2.3 branch.

Discussion
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Explicitly define the encoding.

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Credits for discovering it go to @nicolas-grekas. Cheers!

Travis for PHP 5.6 cannot be enabled yet as there's one more test failing.

re #10714 #10714

Commits
-------

619ff58 Explicitly define the encoding.

src/Symfony/Component/Console/Application.php

@@ -1151,7 +1151,7 @@ class Application
         $line = '';
         foreach (preg_split('//u', $utf8String) as $char) {
             // test if $char could be appended to current line
-            if (mb_strwidth($line.$char) <= $width) {
+            if (mb_strwidth($line.$char, 'utf8') <= $width) {
                 $line .= $char;
                 continue;
             }

src/Symfony/Component/Console/Tests/Fixtures/application_renderexception_doublewidth2.txt

@@ -1,11 +1,10 @@
 
 
-                             
-  [Exception]                
-  コマンドの実行中に         
-  エラーが発生しまし         
-  た。                       
-                             
+                              
+  [Exception]                 
+  コマンドの実行中にエラーが  
+  発生しました。              
+                              
 
 
 foo