Security/PHPFilterFunctions: remove redundant strtoupper() calls

The `isset( $this->restricted_filters[ $parameters[3]['raw'] ] )` check on the array is case-sensitive, so if the filter constant name was not in upper case already, it wouldn't be matched anyhow.

Also note: the case-sensitivity is correct as constants in PHP are case-sensitive (unless explicitly declared as case-insensitive, which these aren't: https://3v4l.org/vq53U#veol).

Includes updating one of the pre-existing tests to document this.

Author: jrfnl

WordPressVIPMinimum/Sniffs/Security/PHPFilterFunctionsSniff.php

@@ -69,7 +69,7 @@ public function process_parameters( $stackPtr, $group_name, $matched_content, $p
 
 			if ( isset( $parameters[3], $this->restricted_filters[ $parameters[3]['raw'] ] ) ) {
 				$message = 'Please use an appropriate filter to sanitize, as "%s" does no filtering, see: http://php.net/manual/en/filter.filters.sanitize.php.';
-				$data    = [ strtoupper( $parameters[3]['raw'] ) ];
+				$data    = [ $parameters[3]['raw'] ];
 				$this->phpcsFile->addWarning( $message, $stackPtr, 'RestrictedFilter', $data );
 			}
 		} else {
@@ -81,7 +81,7 @@ public function process_parameters( $stackPtr, $group_name, $matched_content, $p
 
 			if ( isset( $parameters[2], $this->restricted_filters[ $parameters[2]['raw'] ] ) ) {
 				$message = 'Please use an appropriate filter to sanitize, as "%s" does no filtering, see http://php.net/manual/en/filter.filters.sanitize.php.';
-				$data    = [ strtoupper( $parameters[2]['raw'] ) ];
+				$data    = [ $parameters[2]['raw'] ];
 				$this->phpcsFile->addWarning( $message, $stackPtr, 'RestrictedFilter', $data );
 			}
 		}

WordPressVIPMinimum/Tests/Security/PHPFilterFunctionsUnitTest.inc

@@ -28,7 +28,7 @@ filter_var( $url, FILTER_SANITIZE_URL );
 \filter_var( 'test', FILTER_SANITIZE_STRING );
 FILTER_INPUT( INPUT_GET, 'foo', FILTER_SANITIZE_STRING, );
 filter_input( INPUT_GET,  "foo"   , FILTER_SANITIZE_STRING );
-filter_input_array( $array, FILTER_SANITIZE_STRING );
+filter_input_array( $array, filter_default ); // Constants are case-sensitive, so this is not the FILTER_DEFAULT constant.
 
 // Ignore as undetermined.
 filter_var(  "test", get_filter() );