fix jpeg autorotate for orientation 3

we were not clearing the orientation tag if width and height were
unaltered by the orientation change

see https://github.com/libvips/libvips/discussions/3268

thanks zhifengzhuang

ChangeLog

@@ -1,10 +1,11 @@
-xx/1/23 8.14.1
+9/1/23 8.14.1
 
 - add vips_thread_isworker() compatibility function [remicollet]
 - add vips_semaphore_down_timeout() [kleisauke]
 - idle threads are removed after 15s [kleisauke]
 - fix version number in gtk-doc index [kleisauke]
 - save mono fits images as NAXIS=2 [ewelot]
+- fix jpeg `autorotate` for orientation 3 [zhifengzhuang]
 
 22/12/22 8.14.0
 

libvips/foreign/jpeg2vips.c

@@ -979,9 +979,10 @@ vips__jpeg_read( ReadJpeg *jpeg, VipsImage *out, gboolean header_only )
 
 		/* Swap width and height if we're going to rotate this image.
 		 */
-		if( jpeg->autorotate &&
-			vips_image_get_orientation_swap( out ) ) {
-			VIPS_SWAP( int, out->Xsize, out->Ysize );
+		if( jpeg->autorotate ) {
+			if( vips_image_get_orientation_swap( out ) ) 
+				VIPS_SWAP( int, out->Xsize, out->Ysize );
+
 			vips_autorot_remove_angle( out ); 
 		}
 	}