Remove one unnecessary LogicException from ReferenceStack

This exception was introduced very late in the patch I38c9929. It
already caused trouble. This here is essentially a revert. It restores
the previous behavior where this edge-case was silently ignored. The
worst thing that can happen is that appendText() creates an incomplete
entry in the $this->refs array, which will be rendered at the end. The
user can see it then.

As of now we are not aware of a code path where this would even be
possible. Still this does make the code *more* robust by not making it
explode, but give the user something they can work with.

Bug: T243221
Change-Id: I2e2d29bbd557090981903fcc2ece8796fafa4aa4

src/Cite.php

@@ -409,7 +409,7 @@ class Cite {
 	 *
 	 * @param Parser $parser
 	 * @param ?string $text Raw, untrimmed wikitext content of the <references> tag, if any
-	 * @param string[] $argv Arguments as given in <references name=…>, already trimmed
+	 * @param string[] $argv Arguments as given in <references …>, already trimmed
 	 *
 	 * @return string|false False in case a <references> tag is not allowed in the current context
 	 */
@@ -429,7 +429,7 @@ class Cite {
 	 *
 	 * @param Parser $parser
 	 * @param ?string $text Raw, untrimmed wikitext content of the <references> tag, if any
-	 * @param string[] $argv Arguments as given in <references name=…>, already trimmed
+	 * @param string[] $argv Arguments as given in <references …>, already trimmed
 	 *
 	 * @return string HTML
 	 */

src/ReferenceStack.php

@@ -424,10 +424,6 @@ class ReferenceStack {
 	 * @param string $text
 	 */
 	public function appendText( string $group, string $name, string $text ) {
-		if ( !isset( $this->refs[$group][$name] ) ) {
-			throw new LogicException( "Unknown ref \"$name\" in group \"$group\"" );
-		}
-
 		if ( isset( $this->refs[$group][$name]['text'] ) ) {
 			$this->refs[$group][$name]['text'] .= $text;
 		} else {

tests/phpunit/unit/ReferenceStackTest.php

@@ -1050,22 +1050,11 @@ class ReferenceStackTest extends \MediaWikiUnitTestCase {
 		$this->assertSame( [], $stack->getGroupRefs( 'empty' ) );
 	}
 
-	/**
-	 * @covers ::appendText
-	 */
-	public function testAppendText_failure() {
-		$stack = $this->newStack();
-
-		$this->expectException( LogicException::class );
-		$stack->appendText( 'group', 'name', 'the-text' );
-	}
-
 	/**
 	 * @covers ::appendText
 	 */
 	public function testAppendText() {
 		$stack = $this->newStack();
-		$stack->refs = [ 'group' => [ 'name' => [] ] ];
 
 		$stack->appendText( 'group', 'name', 'set' );
 		$this->assertSame( [ 'text' => 'set' ], $stack->refs['group']['name'] );