I18N: Fix warnings in JavaScript translations.

Fixes an undefined index PHP warning in the load_script_textdomain function and a non-interrupting JS error when registering a domain which has no translations.

Props omarreiss, ocean90, georgestephanis.
Fixes #45256.


git-svn-id: https://develop.svn.wordpress.org/branches/5.0@43898 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class.wp-scripts.php

@@ -528,7 +528,8 @@ public function print_translations( $handle, $echo = true ) {
 		$json_translations = load_script_textdomain( $handle, $domain, $path );
 
 		if ( ! $json_translations ) {
-			return false;
+			// Register empty locale data object to ensure the domain still exists.
+			$json_translations = '{ "locale_data": { "messages": { "": {} } } }';
 		}
 
 		$output = '(function( translations ){' .

src/wp-includes/l10n.php

@@ -923,18 +923,14 @@ function load_script_textdomain( $handle, $domain, $path = null ) {
 
 		$relative = array_slice( $relative, 2 );
 		$relative = implode( '/', $relative );
-	} else if (
-		! isset( $site_url['path'] ) &&
-		( ! isset( $src_url['host'] ) || $src_url['host'] !== $site_url['host'] )
-	) {
-		$relative = trim( $src_url['path'], '/' );
-	} else if (
-		( strpos( $src_url['path'], $site_url['path'] ) === 0 ) &&
-		( ! isset( $src_url['host'] ) || $src_url['host'] !== $site_url['host'] )
-	) {
-		// Make the src relative to the WP root.
-		$relative = substr( $src, strlen( $site_url['path'] ) );
-		$relative = trim( $relative, '/' );
+	} elseif ( ! isset( $src_url['host'] ) || $src_url['host'] !== $site_url['host'] ) {
+		if ( ! isset( $site_url['path'] ) ) {
+			$relative = trim( $src_url['path'], '/' );
+		} elseif ( ( strpos( $src_url['path'], $site_url['path'] ) === 0 ) ) {
+			// Make the src relative to the WP root.
+			$relative = substr( $src, strlen( $site_url['path'] ) );
+			$relative = trim( $relative, '/' );
+		}
 	}
 
 	// If the source is not from WP.

tests/phpunit/tests/dependencies/scripts.php

@@ -863,7 +863,11 @@ public function test_wp_set_script_translations_when_translation_file_does_not_e
 		wp_set_script_translations( 'test-example', 'admin',  DIR_TESTDATA . '/languages/' );
 
 		$expected  = "<script type='text/javascript' src='/wp-includes/js/dist/wp-i18n.js'></script>";
-		$expected .= "\n<script type='text/javascript' src='/wp-admin/js/script.js'></script>\n";
+		$expected .= "\n<script type='text/javascript'>\n(function( translations ){" .
+		             "translations.locale_data.messages[\"\"].domain = \"admin\";" .
+		             "wp.i18n.setLocaleData( translations.locale_data.messages, \"admin\" );" .
+		             "})({ \"locale_data\": { \"messages\": { \"\": {} } } });\n</script>\n";
+		$expected .= "<script type='text/javascript' src='/wp-admin/js/script.js'></script>\n";
 
 		$this->assertEquals( $expected, get_echo( 'wp_print_scripts' ) );
 	}