From c05e49c71a72adeb4f1fc0406292fd94e20bd03e Mon Sep 17 00:00:00 2001
From: tjhunt <tjhunt>
Date: Wed, 22 Jul 2009 02:34:24 +0000
Subject: [PATCH] themes: MDL-19077 make sure that errors displayed by blocks
 are displayed properly.

Note: blocks should not be calling print_error anyway, but some did!
---
 lib/setuplib.php | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/setuplib.php b/lib/setuplib.php
index 76445e10c6..28e87765f6 100644
--- a/lib/setuplib.php
+++ b/lib/setuplib.php
@@ -238,10 +238,20 @@ function print_error($errorcode, $module = 'error', $link = '', $a = null) {
     // Errors in unit test become exceptions, so you can unit test code that might call print_error().
     if (!empty($UNITTEST->running)) {
         throw new moodle_exception($errorcode, $module, $link, $a);
+    } else {
+        // It is really bad if library code calls print_error when output buffering
+        // is on.
+        while (ob_get_level() > 0) {
+            ob_end_clean();
+        }
     }
 
     list($message, $moreinfourl, $link) = prepare_error_message($errorcode, $module, $link, $a);
-    echo $OUTPUT->fatal_error($message, $moreinfourl, $link, debug_backtrace());
+    if (is_stacktrace_during_output_init(debug_backtrace())) {
+        echo bootstrap_renderer::early_error($message, $moreinfourl, $link, debug_backtrace());
+    } else {
+        echo $OUTPUT->fatal_error($message, $moreinfourl, $link, debug_backtrace());
+    }
 
     exit(1); // General error code
 }
-- 
2.39.5