Remove error handler's "errcontext" parameter

The $errcontext parameter for the error handler function has been
deprecated in PHP 7.2.

We currently use this parameter to display some of the local variables
when an error is triggered and $g_show_detailed_errors = ON, but the
output is broken and difficult to read since 2.x was released.

Considering the deprecation notice, it does not make sense to fix the
layout now since the raw data will no longer be available in the next
major PHP release.

This commit changes the error handler's signature, and removes all code
dedicated to printing Context information on the detailed error page.

Fixes #23942

core/error_api.php

@@ -130,15 +130,14 @@ function error_stack_trace( $p_exception = null ) {
  * @param string  $p_error   Contains the error message, as a string.
  * @param string  $p_file    Contains the filename that the error was raised in, as a string.
  * @param integer $p_line    Contains the line number the error was raised at, as an integer.
- * @param array   $p_context To the active symbol table at the point the error occurred (optional).
  * @return void
  * @uses lang_api.php
  * @uses config_api.php
  * @uses compress_api.php
  * @uses database_api.php (optional)
  * @uses html_api.php (optional)
  */
-function error_handler( $p_type, $p_error, $p_file, $p_line, array $p_context ) {
+function error_handler( $p_type, $p_error, $p_file, $p_line ) {
 	global $g_error_parameters, $g_error_handled, $g_error_proceed_url;
 	global $g_error_send_page_header;
 
@@ -352,7 +351,7 @@ function error_handler( $p_type, $p_error, $p_file, $p_line, array $p_context )
 				echo '</div>', "\n";
 
 				if( $t_show_detailed_errors ) {
-					error_print_details( $p_file, $p_line, $p_context );
+					error_print_details( $p_file, $p_line );
 					error_print_stack_trace();
 				}
 				echo '</div></div>';
@@ -426,13 +425,12 @@ function error_print_delayed() {
 }
 
 /**
- * Print out the error details including context
+ * Print out the error details
  * @param string  $p_file    File error occurred in.
  * @param integer $p_line    Line number error occurred on.
- * @param array   $p_context Error context.
  * @return void
  */
-function error_print_details( $p_file, $p_line, array $p_context ) {
+function error_print_details( $p_file, $p_line ) {
 ?>
 	<div class="error-details">
 		<hr>
@@ -447,54 +445,10 @@ function error_print_details( $p_file, $p_line, array $p_context ) {
 				<span class="code"><?php echo $p_line ?></span>
 			</li>
 		</ul>
-
-		<h3>Context</h3>
-		<?php error_print_context( $p_context )?>
 	</div>
 <?php
 }
 
-/**
- * Print out the variable context given
- * @param array $p_context Error context.
- * @return void
- */
-function error_print_context( array $p_context ) {
-	if( !is_array( $p_context ) ) {
-		return;
-	}
-
-	echo '<table class="width100" style="table-layout:fixed;"><tr><th>Variable</th><th>Value</th><th>Type</th></tr>';
-
-	# print normal variables
-	foreach( $p_context as $t_var => $t_val ) {
-		if( !is_array( $t_val ) && !is_object( $t_val ) ) {
-			$t_type = gettype( $t_val );
-			$t_val = htmlentities( (string)$t_val, ENT_COMPAT, 'UTF-8' );
-
-			# Mask Passwords
-			if( strpos( $t_var, 'password' ) !== false ) {
-				$t_val = '**********';
-			}
-
-			echo '<tr><td style="width=20%; word-wrap:break-word; overflow:auto;">', $t_var,
-				'</td><td style="width=70%; word-wrap:break-word; overflow:auto;">', $t_val,
-				'</td><td style="width=10%;">', $t_type, '</td></tr>', "\n";
-		}
-	}
-
-	# print arrays
-	foreach( $p_context as $t_var => $t_val ) {
-		if( is_array( $t_val ) && ( $t_var != 'GLOBALS' ) ) {
-			echo '<tr><td colspan="3" style="word-wrap:break-word"><br /><strong>', $t_var, '</strong></td></tr>';
-			echo '<tr><td colspan="3">';
-			error_print_context( $t_val );
-			echo '</td></tr>';
-		}
-	}
-
-	echo '</table>';
-}
 
 /**
  * Get the stack trace as a string that can be logged or echoed to CLI output.