API Cleanup: renamed '_badcontinue'->'badcontinue', one die()

* If a query module has 'continue' parameter, it will auto-report
that it has 'badcontinue' error.
* Added APIQueryBase::DieUsageContinueIf( $condition ) that shows
correct badcontinue error if $condition is true.

Change-Id: I9c48bda6de0cde3c117ad24460bddf6980279633

22 files changed, 52 insertions, 128 deletions

diff --git a/includes/api/ApiQueryAllCategories.php b/includes/api/ApiQueryAllCategories.php
index c2beaec6a7e5..6ada4aa716e1 100644
--- a/includes/api/ApiQueryAllCategories.php
+++ b/includes/api/ApiQueryAllCategories.php
@@ -60,10 +60,7 @@ class ApiQueryAllCategories extends ApiQueryGeneratorBase {
 
 		if ( !is_null( $params['continue'] ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 1 ) {
-				$this->dieUsage( "Invalid continue param. You should pass the " .
-					"original value returned by the previous query", "_badcontinue" );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 1 );
 			$op = $params['dir'] == 'descending' ? '<' : '>';
 			$cont_from = $db->addQuotes( $cont[0] );
 			$this->addWhere( "cat_title $op= $cont_from" );
@@ -224,12 +221,6 @@ class ApiQueryAllCategories extends ApiQueryGeneratorBase {
 		return 'Enumerate all categories';
 	}
 
-	public function getPossibleErrors() {
-		return array_merge( parent::getPossibleErrors(), array(
-			array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
-		) );
-	}
-
 	public function getExamples() {
 		return array(
 			'api.php?action=query&list=allcategories&acprop=size',
diff --git a/includes/api/ApiQueryAllImages.php b/includes/api/ApiQueryAllImages.php
index 2319263dcf2b..c78f0f3572c4 100644
--- a/includes/api/ApiQueryAllImages.php
+++ b/includes/api/ApiQueryAllImages.php
@@ -113,10 +113,7 @@ class ApiQueryAllImages extends ApiQueryGeneratorBase {
 			// Pagination
 			if ( !is_null( $params['continue'] ) ) {
 				$cont = explode( '|', $params['continue'] );
-				if ( count( $cont ) != 1 ) {
-					$this->dieUsage( 'Invalid continue param. You should pass the ' .
-						'original value returned by the previous query', '_badcontinue' );
-				}
+				$this->dieContinueUsageIf( count( $cont ) != 1 );
 				$op = ( $ascendingOrder ? '>' : '<' );
 				$continueFrom = $db->addQuotes( $cont[0] );
 				$this->addWhere( "img_name $op= $continueFrom" );
@@ -385,7 +382,6 @@ class ApiQueryAllImages extends ApiQueryGeneratorBase {
 			array( 'code' => 'mimesearchdisabled', 'info' => 'MIME search disabled in Miser Mode' ),
 			array( 'code' => 'invalidsha1hash', 'info' => 'The SHA1 hash provided is not valid' ),
 			array( 'code' => 'invalidsha1base36hash', 'info' => 'The SHA1Base36 hash provided is not valid' ),
-			array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
 		) );
 	}
 
diff --git a/includes/api/ApiQueryAllLinks.php b/includes/api/ApiQueryAllLinks.php
index 3b478b081a4e..620a394af35a 100644
--- a/includes/api/ApiQueryAllLinks.php
+++ b/includes/api/ApiQueryAllLinks.php
@@ -104,15 +104,11 @@ class ApiQueryAllLinks extends ApiQueryGeneratorBase {
 			$continueArr = explode( '|', $params['continue'] );
 			$op = $params['dir'] == 'descending' ? '<' : '>';
 			if ( $params['unique'] ) {
-				if ( count( $continueArr ) != 1 ) {
-					$this->dieUsage( 'Invalid continue parameter', 'badcontinue' );
-				}
+				$this->dieContinueUsageIf( count( $continueArr ) != 1 );
 				$continueTitle = $db->addQuotes( $continueArr[0] );
 				$this->addWhere( "{$pfx}title $op= $continueTitle" );
 			} else {
-				if ( count( $continueArr ) != 2 ) {
-					$this->dieUsage( 'Invalid continue parameter', 'badcontinue' );
-				}
+				$this->dieContinueUsageIf( count( $continueArr ) != 2 );
 				$continueTitle = $db->addQuotes( $continueArr[0] );
 				$continueFrom = intval( $continueArr[1] );
 				$this->addWhere(
@@ -279,7 +275,6 @@ class ApiQueryAllLinks extends ApiQueryGeneratorBase {
 		$link = $this->descriptionLink;
 		return array_merge( parent::getPossibleErrors(), array(
 			array( 'code' => 'params', 'info' => "{$m} cannot return corresponding page ids in unique {$link}s mode" ),
-			array( 'code' => 'badcontinue', 'info' => 'Invalid continue parameter' ),
 		) );
 	}
 
diff --git a/includes/api/ApiQueryAllPages.php b/includes/api/ApiQueryAllPages.php
index a5abae76abca..b180572bf858 100644
--- a/includes/api/ApiQueryAllPages.php
+++ b/includes/api/ApiQueryAllPages.php
@@ -69,10 +69,7 @@ class ApiQueryAllPages extends ApiQueryGeneratorBase {
 
 		if ( !is_null( $params['continue'] ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 1 ) {
-				$this->dieUsage( "Invalid continue param. You should pass the " .
-					"original value returned by the previous query", "_badcontinue" );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 1 );
 			$op = $params['dir'] == 'descending' ? '<' : '>';
 			$cont_from = $db->addQuotes( $cont[0] );
 			$this->addWhere( "page_title $op= $cont_from" );
@@ -336,7 +333,6 @@ class ApiQueryAllPages extends ApiQueryGeneratorBase {
 		return array_merge( parent::getPossibleErrors(), array(
 			array( 'code' => 'params', 'info' => 'Use "gapfilterredir=nonredirects" option instead of "redirects" when using allpages as a generator' ),
 			array( 'code' => 'params', 'info' => 'prlevel may not be used without prtype' ),
-			array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
 		) );
 	}
 
diff --git a/includes/api/ApiQueryBacklinks.php b/includes/api/ApiQueryBacklinks.php
index 6f45726b38a6..bf918ddde2a2 100644
--- a/includes/api/ApiQueryBacklinks.php
+++ b/includes/api/ApiQueryBacklinks.php
@@ -406,20 +406,14 @@ class ApiQueryBacklinks extends ApiQueryGeneratorBase {
 		// null stuff out now so we know what's set and what isn't
 		$this->rootTitle = $this->contID = $this->redirID = null;
 		$rootNs = intval( $continueList[0] );
-		if ( $rootNs === 0 && $continueList[0] !== '0' ) {
-			// Illegal continue parameter
-			$this->dieUsage( 'Invalid continue param. You should pass the original value returned by the previous query', '_badcontinue' );
-		}
+		$this->dieContinueUsageIf( $rootNs === 0 && $continueList[0] !== '0' );
+
 		$this->rootTitle = Title::makeTitleSafe( $rootNs, $continueList[1] );
+		$this->dieContinueUsageIf( !$this->rootTitle );
 
-		if ( !$this->rootTitle ) {
-			$this->dieUsage( 'Invalid continue param. You should pass the original value returned by the previous query', '_badcontinue' );
-		}
 		$contID = intval( $continueList[2] );
+		$this->dieContinueUsageIf( $contID === 0 && $continueList[2] !== '0' );
 
-		if ( $contID === 0 && $continueList[2] !== '0' ) {
-			$this->dieUsage( 'Invalid continue param. You should pass the original value returned by the previous query', '_badcontinue' );
-		}
 		$this->contID = $contID;
 		$id2 = isset( $continueList[3] ) ? $continueList[3] : null;
 		$redirID = intval( $id2 );
@@ -535,7 +529,6 @@ class ApiQueryBacklinks extends ApiQueryGeneratorBase {
 			$this->getTitleOrPageIdErrorMessage(),
 			array(
 				array( 'code' => 'bad_image_title', 'info' => "The title for {$this->getModuleName()} query must be an image" ),
-				array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
 			)
 		);
 	}
diff --git a/includes/api/ApiQueryBase.php b/includes/api/ApiQueryBase.php
index 5f4d9f9ce7b4..e36109a2d3d7 100644
--- a/includes/api/ApiQueryBase.php
+++ b/includes/api/ApiQueryBase.php
@@ -375,6 +375,19 @@ abstract class ApiQueryBase extends ApiBase {
 	}
 
 	/**
+	 * Die with the $prefix.'badcontinue' error. This call is common enough to make it into the base method.
+	 * @param $condition boolean will only die if this value is true
+	 * @since 1.21
+	 */
+	protected function dieContinueUsageIf( $condition ) {
+		if ( $condition ) {
+			$this->dieUsage(
+				'Invalid continue param. You should pass the original value returned by the previous query',
+				'badcontinue' );
+		}
+	}
+
+	/**
 	 * Get the Query database connection (read-only)
 	 * @return DatabaseBase
 	 */
@@ -549,10 +562,21 @@ abstract class ApiQueryBase extends ApiBase {
 	 * @return array
 	 */
 	public function getPossibleErrors() {
-		return array_merge( parent::getPossibleErrors(), array(
+		$errors = parent::getPossibleErrors();
+		$errors = array_merge( $errors, array(
 			array( 'invalidtitle', 'title' ),
 			array( 'invalidtitle', 'key' ),
 		) );
+		$params = $this->getFinalParams();
+		if ( array_key_exists( 'continue', $params ) ) {
+			$errors = array_merge( $errors, array(
+				array(
+					'code' => 'badcontinue',
+					'info' => 'Invalid continue param. You should pass the original value returned by the previous query'
+				),
+			) );
+		}
+		return $errors;
 	}
 
 	/**
diff --git a/includes/api/ApiQueryCategories.php b/includes/api/ApiQueryCategories.php
index 309c2ce90d1f..f05bb262de96 100644
--- a/includes/api/ApiQueryCategories.php
+++ b/includes/api/ApiQueryCategories.php
@@ -85,10 +85,7 @@ class ApiQueryCategories extends ApiQueryGeneratorBase {
 
 		if ( !is_null( $params['continue'] ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 2 ) {
-				$this->dieUsage( "Invalid continue param. You should pass the " .
-					"original value returned by the previous query", "_badcontinue" );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 2 );
 			$op = $params['dir'] == 'descending' ? '<' : '>';
 			$clfrom = intval( $cont[0] );
 			$clto = $this->getDB()->addQuotes( $cont[1] );
diff --git a/includes/api/ApiQueryCategoryMembers.php b/includes/api/ApiQueryCategoryMembers.php
index a07b049aa401..ca24f2b82233 100644
--- a/includes/api/ApiQueryCategoryMembers.php
+++ b/includes/api/ApiQueryCategoryMembers.php
@@ -106,11 +106,7 @@ class ApiQueryCategoryMembers extends ApiQueryGeneratorBase {
 		} else {
 			if ( $params['continue'] ) {
 				$cont = explode( '|', $params['continue'], 3 );
-				if ( count( $cont ) != 3 ) {
-					$this->dieUsage( 'Invalid continue param. You should pass the original value returned '.
-						'by the previous query', '_badcontinue'
-					);
-				}
+				$this->dieContinueUsageIf( count( $cont ) != 3 );
 
 				// Remove the types to skip from $queryTypes
 				$contTypeIndex = array_search( $cont[0], $queryTypes );
@@ -403,7 +399,6 @@ class ApiQueryCategoryMembers extends ApiQueryGeneratorBase {
 			$this->getTitleOrPageIdErrorMessage(),
 			array(
 				array( 'code' => 'invalidcategory', 'info' => 'The category name you entered is not valid' ),
-				array( 'code' => 'badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
 			)
 		);
 	}
diff --git a/includes/api/ApiQueryDeletedrevs.php b/includes/api/ApiQueryDeletedrevs.php
index 8903e4686fa6..9eab651f4d51 100644
--- a/includes/api/ApiQueryDeletedrevs.php
+++ b/includes/api/ApiQueryDeletedrevs.php
@@ -160,10 +160,9 @@ class ApiQueryDeletedrevs extends ApiQueryBase {
 
 		if ( !is_null( $params['continue'] ) && ( $mode == 'all' || $mode == 'revs' ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 3 ) {
-				$this->dieUsage( 'Invalid continue param. You should pass the original value returned by the previous query', 'badcontinue' );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 3 );
 			$ns = intval( $cont[0] );
+			$this->dieContinueUsageIf( strval( $ns ) !== $cont[0] );
 			$title = $db->addQuotes( $cont[1] );
 			$ts = $db->addQuotes( $db->timestamp( $cont[2] ) );
 			$op = ( $dir == 'newer' ? '>' : '<' );
@@ -397,7 +396,6 @@ class ApiQueryDeletedrevs extends ApiQueryBase {
 			array( 'code' => 'permissiondenied', 'info' => 'You don\'t have permission to view deleted revision information' ),
 			array( 'code' => 'badparams', 'info' => 'user and excludeuser cannot be used together' ),
 			array( 'code' => 'permissiondenied', 'info' => 'You don\'t have permission to view deleted revision content' ),
-			array( 'code' => 'badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
 			array( 'code' => 'badparams', 'info' => "The 'from' parameter cannot be used in modes 1 or 2" ),
 			array( 'code' => 'badparams', 'info' => "The 'to' parameter cannot be used in modes 1 or 2" ),
 			array( 'code' => 'badparams', 'info' => "The 'prefix' parameter cannot be used in modes 1 or 2" ),
diff --git a/includes/api/ApiQueryDuplicateFiles.php b/includes/api/ApiQueryDuplicateFiles.php
index f088062cb92b..d4a486a999f8 100644
--- a/includes/api/ApiQueryDuplicateFiles.php
+++ b/includes/api/ApiQueryDuplicateFiles.php
@@ -66,10 +66,7 @@ class ApiQueryDuplicateFiles extends ApiQueryGeneratorBase {
 		$skipUntilThisDup = false;
 		if ( isset( $params['continue'] ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 2 ) {
-				$this->dieUsage( 'Invalid continue param. You should pass the ' .
-					'original value returned by the previous query', '_badcontinue' );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 2 );
 			$fromImage = $cont[0];
 			$skipUntilThisDup = $cont[1];
 			// Filter out any images before $fromImage
@@ -204,12 +201,6 @@ class ApiQueryDuplicateFiles extends ApiQueryGeneratorBase {
 		return 'List all files that are duplicates of the given file(s) based on hash values';
 	}
 
-	public function getPossibleErrors() {
-		return array_merge( parent::getPossibleErrors(), array(
-			array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
-		) );
-	}
-
 	public function getExamples() {
 		return array(
 			'api.php?action=query&titles=File:Albert_Einstein_Head.jpg&prop=duplicatefiles',
diff --git a/includes/api/ApiQueryFilearchive.php b/includes/api/ApiQueryFilearchive.php
index 7ec47fa91f5c..fcffc4d41821 100644
--- a/includes/api/ApiQueryFilearchive.php
+++ b/includes/api/ApiQueryFilearchive.php
@@ -77,10 +77,7 @@ class ApiQueryFilearchive extends ApiQueryBase {
 
 		if ( !is_null( $params['continue'] ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 1 ) {
-				$this->dieUsage( "Invalid continue param. You should pass the " .
-					"original value returned by the previous query", "_badcontinue" );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 1 );
 			$op = $params['dir'] == 'descending' ? '<' : '>';
 			$cont_from = $db->addQuotes( $cont[0] );
 			$this->addWhere( "fa_name $op= $cont_from" );
@@ -366,7 +363,6 @@ class ApiQueryFilearchive extends ApiQueryBase {
 			array( 'code' => 'hashsearchdisabled', 'info' => 'Search by hash disabled in Miser Mode' ),
 			array( 'code' => 'invalidsha1hash', 'info' => 'The SHA1 hash provided is not valid' ),
 			array( 'code' => 'invalidsha1base36hash', 'info' => 'The SHA1Base36 hash provided is not valid' ),
-			array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
 		) );
 	}
 
diff --git a/includes/api/ApiQueryIWBacklinks.php b/includes/api/ApiQueryIWBacklinks.php
index c5012f085d8a..283115d80bcc 100644
--- a/includes/api/ApiQueryIWBacklinks.php
+++ b/includes/api/ApiQueryIWBacklinks.php
@@ -56,10 +56,7 @@ class ApiQueryIWBacklinks extends ApiQueryGeneratorBase {
 
 		if ( !is_null( $params['continue'] ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 3 ) {
-				$this->dieUsage( 'Invalid continue param. You should pass the ' .
-					'original value returned by the previous query', '_badcontinue' );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 3 );
 
 			$db = $this->getDB();
 			$op = $params['dir'] == 'descending' ? '<' : '>';
@@ -233,7 +230,6 @@ class ApiQueryIWBacklinks extends ApiQueryGeneratorBase {
 	public function getPossibleErrors() {
 		return array_merge( parent::getPossibleErrors(), array(
 			array( 'missingparam', 'prefix' ),
-			array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
 		) );
 	}
 
diff --git a/includes/api/ApiQueryIWLinks.php b/includes/api/ApiQueryIWLinks.php
index 30c7f5a80107..8e8a07569925 100644
--- a/includes/api/ApiQueryIWLinks.php
+++ b/includes/api/ApiQueryIWLinks.php
@@ -58,10 +58,7 @@ class ApiQueryIWLinks extends ApiQueryBase {
 
 		if ( !is_null( $params['continue'] ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 3 ) {
-				$this->dieUsage( 'Invalid continue param. You should pass the ' .
-					'original value returned by the previous query', '_badcontinue' );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 3 );
 			$op = $params['dir'] == 'descending' ? '<' : '>';
 			$db = $this->getDB();
 			$iwlfrom = intval( $cont[0] );
@@ -187,7 +184,6 @@ class ApiQueryIWLinks extends ApiQueryBase {
 	public function getPossibleErrors() {
 		return array_merge( parent::getPossibleErrors(), array(
 			array( 'missingparam', 'prefix' ),
-			array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
 		) );
 	}
 
diff --git a/includes/api/ApiQueryImageInfo.php b/includes/api/ApiQueryImageInfo.php
index 0a0b5ddb0a15..88c41a8a1d4e 100644
--- a/includes/api/ApiQueryImageInfo.php
+++ b/includes/api/ApiQueryImageInfo.php
@@ -56,10 +56,7 @@ class ApiQueryImageInfo extends ApiQueryBase {
 			if ( !is_null( $params['continue'] ) ) {
 				$skip = true;
 				$cont = explode( '|', $params['continue'] );
-				if ( count( $cont ) != 2 ) {
-					$this->dieUsage( 'Invalid continue param. You should pass the original ' .
-							'value returned by the previous query', '_badcontinue' );
-				}
+				$this->dieContinueUsageIf( count( $cont ) != 2 );
 				$fromTitle = strval( $cont[0] );
 				$fromTimestamp = $cont[1];
 				// Filter out any titles before $fromTitle
diff --git a/includes/api/ApiQueryImages.php b/includes/api/ApiQueryImages.php
index 6052a75f4573..16d54aad06ee 100644
--- a/includes/api/ApiQueryImages.php
+++ b/includes/api/ApiQueryImages.php
@@ -62,10 +62,7 @@ class ApiQueryImages extends ApiQueryGeneratorBase {
 		$this->addWhereFld( 'il_from', array_keys( $this->getPageSet()->getGoodTitles() ) );
 		if ( !is_null( $params['continue'] ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 2 ) {
-				$this->dieUsage( 'Invalid continue param. You should pass the ' .
-					'original value returned by the previous query', '_badcontinue' );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 2 );
 			$op = $params['dir'] == 'descending' ? '<' : '>';
 			$ilfrom = intval( $cont[0] );
 			$ilto = $this->getDB()->addQuotes( $cont[1] );
@@ -185,12 +182,6 @@ class ApiQueryImages extends ApiQueryGeneratorBase {
 		return 'Returns all images contained on the given page(s)';
 	}
 
-	public function getPossibleErrors() {
-		return array_merge( parent::getPossibleErrors(), array(
-			array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
-		) );
-	}
-
 	public function getExamples() {
 		return array(
 			'api.php?action=query&prop=images&titles=Main%20Page' => 'Get a list of images used in the [[Main Page]]',
diff --git a/includes/api/ApiQueryInfo.php b/includes/api/ApiQueryInfo.php
index dd1326b4f0a2..efbd731fc29a 100644
--- a/includes/api/ApiQueryInfo.php
+++ b/includes/api/ApiQueryInfo.php
@@ -268,10 +268,7 @@ class ApiQueryInfo extends ApiQueryBase {
 			// Throw away any titles we're gonna skip so they don't
 			// clutter queries
 			$cont = explode( '|', $this->params['continue'] );
-			if ( count( $cont ) != 2 ) {
-				$this->dieUsage( 'Invalid continue param. You should pass the original ' .
-						'value returned by the previous query', '_badcontinue' );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 2 );
 			$conttitle = Title::makeTitleSafe( $cont[0], $cont[1] );
 			foreach ( $this->everything as $pageid => $title ) {
 				if ( Title::compare( $title, $conttitle ) >= 0 ) {
@@ -809,12 +806,6 @@ class ApiQueryInfo extends ApiQueryBase {
 		return 'Get basic page information such as namespace, title, last touched date, ...';
 	}
 
-	public function getPossibleErrors() {
-		return array_merge( parent::getPossibleErrors(), array(
-			array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
-		) );
-	}
-
 	public function getExamples() {
 		return array(
 			'api.php?action=query&prop=info&titles=Main%20Page',
diff --git a/includes/api/ApiQueryLangBacklinks.php b/includes/api/ApiQueryLangBacklinks.php
index 3920407b9186..d6346d3ff493 100644
--- a/includes/api/ApiQueryLangBacklinks.php
+++ b/includes/api/ApiQueryLangBacklinks.php
@@ -56,10 +56,7 @@ class ApiQueryLangBacklinks extends ApiQueryGeneratorBase {
 
 		if ( !is_null( $params['continue'] ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 3 ) {
-				$this->dieUsage( 'Invalid continue param. You should pass the ' .
-					'original value returned by the previous query', '_badcontinue' );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 3 );
 
 			$db = $this->getDB();
 			$op = $params['dir'] == 'descending' ? '<' : '>';
@@ -233,7 +230,6 @@ class ApiQueryLangBacklinks extends ApiQueryGeneratorBase {
 	public function getPossibleErrors() {
 		return array_merge( parent::getPossibleErrors(), array(
 			array( 'missingparam', 'lang' ),
-			array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
 		) );
 	}
 
diff --git a/includes/api/ApiQueryLangLinks.php b/includes/api/ApiQueryLangLinks.php
index 3109a0908680..9c54cfa285ee 100644
--- a/includes/api/ApiQueryLangLinks.php
+++ b/includes/api/ApiQueryLangLinks.php
@@ -56,10 +56,7 @@ class ApiQueryLangLinks extends ApiQueryBase {
 		$this->addWhereFld( 'll_from', array_keys( $this->getPageSet()->getGoodTitles() ) );
 		if ( !is_null( $params['continue'] ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 2 ) {
-				$this->dieUsage( 'Invalid continue param. You should pass the ' .
-					'original value returned by the previous query', '_badcontinue' );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 2 );
 			$op = $params['dir'] == 'descending' ? '<' : '>';
 			$llfrom = intval( $cont[0] );
 			$lllang = $this->getDB()->addQuotes( $cont[1] );
@@ -179,7 +176,6 @@ class ApiQueryLangLinks extends ApiQueryBase {
 	public function getPossibleErrors() {
 		return array_merge( parent::getPossibleErrors(), array(
 			array( 'missingparam', 'lang' ),
-			array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
 		) );
 	}
 
diff --git a/includes/api/ApiQueryLinks.php b/includes/api/ApiQueryLinks.php
index 9e4b7ebb3684..54ee57c15880 100644
--- a/includes/api/ApiQueryLinks.php
+++ b/includes/api/ApiQueryLinks.php
@@ -112,10 +112,7 @@ class ApiQueryLinks extends ApiQueryGeneratorBase {
 
 		if ( !is_null( $params['continue'] ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 3 ) {
-				$this->dieUsage( 'Invalid continue param. You should pass the ' .
-					'original value returned by the previous query', '_badcontinue' );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 3 );
 			$op = $params['dir'] == 'descending' ? '<' : '>';
 			$plfrom = intval( $cont[0] );
 			$plns = intval( $cont[1] );
diff --git a/includes/api/ApiQueryRevisions.php b/includes/api/ApiQueryRevisions.php
index e161f30e1a5d..ecf47a9bb4e9 100644
--- a/includes/api/ApiQueryRevisions.php
+++ b/includes/api/ApiQueryRevisions.php
@@ -338,10 +338,7 @@ class ApiQueryRevisions extends ApiQueryBase {
 
 			if ( !is_null( $params['continue'] ) ) {
 				$cont = explode( '|', $params['continue'] );
-				if ( count( $cont ) != 2 ) {
-					$this->dieUsage( 'Invalid continue param. You should pass the original ' .
-							'value returned by the previous query', '_badcontinue' );
-				}
+				$this->dieContinueUsageIf( count( $cont ) != 2 );
 				$pageid = intval( $cont[0] );
 				$revid = intval( $cont[1] );
 				$this->addWhere(
diff --git a/includes/api/ApiQueryUserContributions.php b/includes/api/ApiQueryUserContributions.php
index f30b1325e12e..96fea1a8e85a 100644
--- a/includes/api/ApiQueryUserContributions.php
+++ b/includes/api/ApiQueryUserContributions.php
@@ -160,10 +160,7 @@ class ApiQueryContributions extends ApiQueryBase {
 		// Handle continue parameter
 		if ( $this->multiUserMode && !is_null( $this->params['continue'] ) ) {
 			$continue = explode( '|', $this->params['continue'] );
-			if ( count( $continue ) != 2 ) {
-				$this->dieUsage( 'Invalid continue param. You should pass the original ' .
-					'value returned by the previous query', '_badcontinue' );
-			}
+			$this->dieContinueUsageIf( count( $continue ) != 2 );
 			$db = $this->getDB();
 			$encUser = $db->addQuotes( $continue[0] );
 			$encTS = $db->addQuotes( $db->timestamp( $continue[1] ) );
diff --git a/includes/api/ApiQueryWatchlistRaw.php b/includes/api/ApiQueryWatchlistRaw.php
index 6b24aef32edc..27b6f747f73b 100644
--- a/includes/api/ApiQueryWatchlistRaw.php
+++ b/includes/api/ApiQueryWatchlistRaw.php
@@ -71,11 +71,9 @@ class ApiQueryWatchlistRaw extends ApiQueryGeneratorBase {
 
 		if ( isset( $params['continue'] ) ) {
 			$cont = explode( '|', $params['continue'] );
-			if ( count( $cont ) != 2 ) {
-				$this->dieUsage( "Invalid continue param. You should pass the " .
-					"original value returned by the previous query", "_badcontinue" );
-			}
+			$this->dieContinueUsageIf( count( $cont ) != 2 );
 			$ns = intval( $cont[0] );
+			$this->dieContinueUsageIf( strval( $ns ) !== $cont[0] );
 			$title = $this->getDB()->addQuotes( $cont[1] );
 			$op = $params['dir'] == 'ascending' ? '>' : '<';
 			$this->addWhere(