Merge "Add vary-revision-exist flag to handle {{REVISIONID}} and parser cache"

2 files changed, 15 insertions, 1 deletions

diff --git a/includes/Revision/RenderedRevision.php b/includes/Revision/RenderedRevision.php
index 094105aae851..d3e5938c8637 100644
--- a/includes/Revision/RenderedRevision.php
+++ b/includes/Revision/RenderedRevision.php
@@ -395,6 +395,14 @@ class RenderedRevision implements SlotRenderingProvider {
 				"$method: Prepared output has vary-revision-id with wrong ID...\n"
 			);
 			return true;
+		} elseif ( $out->getFlag( 'vary-revision-exists' ) ) {
+			// If {{REVISIONID}} resolved to '', it now needs to resolve to '-'.
+			// Note that edit stashing always uses '-', which can be used for both
+			// edit filter checks and canonical parser cache.
+			$this->saveParseLogger->info(
+				"$method: Prepared output has vary-revision-exists...\n"
+			);
+			return true;
 		} else {
 			// NOTE: In the original fix for T135261, the output was discarded if 'vary-user' was
 			// set for a null-edit. The reason was that the original rendering in that case was
diff --git a/includes/parser/Parser.php b/includes/parser/Parser.php
index 9ff731d80178..91de550fad8e 100644
--- a/includes/parser/Parser.php
+++ b/includes/parser/Parser.php
@@ -2607,7 +2607,13 @@ class Parser {
 			// @TODO: disallow this word on all namespaces
 			$this->nsInfo->isContent( $this->mTitle->getNamespace() )
 		) {
-			return $this->mRevisionId ? '-' : '';
+			if ( $this->mRevisionId ) {
+				return '-';
+			} else {
+				$this->mOutput->setFlag( 'vary-revision-exists' );
+
+				return '';
+			}
 		};
 
 		$pageLang = $this->getFunctionLang();