API: Better handle UsageException from the printer itself

Try falling back to use the printer without any of its parameters in
case one of them is what's failing.

Change-Id: I2611550109de4219bf1cc43333d038753e9eb87c

diff --git a/includes/api/ApiFormatBase.php b/includes/api/ApiFormatBase.php
index 26eac08..d078dc4 100644 (file)
--- a/includes/api/ApiFormatBase.php
+++ b/includes/api/ApiFormatBase.php
@@ -32,6 +32,7 @@
 abstract class ApiFormatBase extends ApiBase {
        private $mIsHtml, $mFormat, $mUnescapeAmps, $mHelp;
        private $mBuffer, $mDisabled = false;
+       protected $mForceDefaultParams = false;
 
        /**
         * If $format ends with 'fm', pretty-print the output in HTML.
@@ -107,6 +108,34 @@ abstract class ApiFormatBase extends ApiBase {
                return true;
        }
 
+       /**
+        * Ignore request parameters, force a default.
+        *
+        * Used as a fallback if errors are being thrown.
+        * @since 1.26
+        */
+       public function forceDefaultParams() {
+               $this->mForceDefaultParams = true;
+       }
+
+       /**
+        * Overridden to honor $this->forceDefaultParams(), if applicable
+        * @since 1.26
+        */
+       protected function getParameterFromSettings( $paramName, $paramSettings, $parseLimit ) {
+               if ( !$this->mForceDefaultParams ) {
+                       return parent::getParameterFromSettings( $paramName, $paramSettings, $parseLimit );
+               }
+
+               if ( !is_array( $paramSettings ) ) {
+                       return $paramSettings;
+               } elseif ( isset( $paramSettings[self::PARAM_DFLT] ) ) {
+                       return $paramSettings[self::PARAM_DFLT];
+               } else {
+                       return null;
+               }
+       }
+
        /**
         * Initialize the printer function and prepare the output headers.
         * @param bool $unused Always false since 1.25

diff --git a/includes/api/ApiMain.php b/includes/api/ApiMain.php
index 7e3dcff..2ec3aa8 100644 (file)
--- a/includes/api/ApiMain.php
+++ b/includes/api/ApiMain.php
@@ -495,7 +495,22 @@ class ApiMain extends ApiBase {
                // Reset and print just the error message
                ob_clean();
 
-               $this->printResult( true );
+               // Printer may not be initialized if the extractRequestParams() fails for the main module
+               $this->createErrorPrinter();
+
+               try {
+                       $this->printResult( true );
+               } catch ( UsageException $ex ) {
+                       // The error printer itself is failing. Try suppressing its request
+                       // parameters and redo.
+                       $this->setWarning(
+                               'Error printer failed (will retry without params): ' . $ex->getMessage()
+                       );
+                       $this->mPrinter = null;
+                       $this->createErrorPrinter();
+                       $this->mPrinter->forceDefaultParams();
+                       $this->printResult( true );
+               }
        }
 
        /**
@@ -792,22 +807,14 @@ class ApiMain extends ApiBase {
        }
 
        /**
-        * Replace the result data with the information about an exception.
-        * Returns the error code
-        * @param Exception $e
-        * @return string
+        * Create the printer for error output
         */
-       protected function substituteResultWithError( $e ) {
-               $result = $this->getResult();
-
-               // Printer may not be initialized if the extractRequestParams() fails for the main module
+       private function createErrorPrinter() {
                if ( !isset( $this->mPrinter ) ) {
-                       // The printer has not been created yet. Try to manually get formatter value.
                        $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
                        if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
                                $value = self::API_DEFAULT_FORMAT;
                        }
-
                        $this->mPrinter = $this->createPrinterByName( $value );
                }
 
@@ -816,10 +823,16 @@ class ApiMain extends ApiBase {
                if ( !$this->mPrinter->canPrintErrors() ) {
                        $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
                }
+       }
 
-               // Update raw mode flag for the selected printer.
-               $result->setRawMode( $this->mPrinter->getNeedsRawData() );
-
+       /**
+        * Replace the result data with the information about an exception.
+        * Returns the error code
+        * @param Exception $e
+        * @return string
+        */
+       protected function substituteResultWithError( $e ) {
+               $result = $this->getResult();
                $config = $this->getConfig();
 
                if ( $e instanceof UsageException ) {