Here is the matter:
ini_set(\'display_errors\', \'1\');
ini_set(\'safe_mode\', \'0\');
ini_set(\'allow_url_fopen\', \'1\');
ini_set(\'allow_url_include\', \'1\');
My answer might be off-topic but I almost always come back to this question via Google when my ini_set calls are not working. Sharing my case might help others to solve a issue with ini_set more quickly.
So, in my case display_errors is disabled but PHP displays the errors in the browser anyway although I enabled log_errors and set error_log to C:\Windows\Temp\PHP_error.log.
First impression is always that ini_set is not working BUT it might be a permission issue. If PHP cannot access the log file then it will simply send the errors to the browser.
Solution: make sure PHP has the permission to access and write the log file.