avm2: Improve accuracy of gotoAndPlay / gotoAndStop (partially fix #8954)

Partially based on AVM1 implementation, partially based on the new
regression tests added in this commit.

core/src/avm2/globals/flash/display/movieclip.rs

@@ -388,13 +388,17 @@ pub fn goto_frame<'gc>(
             .scene_label_to_number(&v.coerce_to_string(activation)?)
             .map(|v| v.saturating_sub(1)),
     }
-    .unwrap_or(0) as u32;
+    .unwrap_or(0) as i32;
     let frame = match frame_or_label {
-        Value::Integer(i) => i as u32 + scene,
+        Value::Integer(i) => i + scene,
         frame_or_label => {
             let frame_or_label = frame_or_label.coerce_to_string(activation)?;
-            if let Ok(frame) = frame_or_label.parse::<u32>() {
-                frame + scene
+            let frame = crate::avm2::value::string_to_int(&frame_or_label, 10, true);
+            if !frame.is_nan() {
+                (frame as i32)
+                    .wrapping_sub(1)
+                    .wrapping_add(scene)
+                    .saturating_add(1)
             } else {
                 if let Some(scene) = args.get(1).cloned() {
                     //If the user specified a scene, we need to validate that
@@ -410,12 +414,12 @@ pub fn goto_frame<'gc>(
 
                 mc.frame_label_to_number(&frame_or_label).ok_or_else(|| {
                     format!("ArgumentError: {frame_or_label} is not a valid frame label.")
-                })? as u32
+                })? as i32
             }
         }
     };
 
-    mc.goto_frame(&mut activation.context, frame as u16, stop);
+    mc.goto_frame(&mut activation.context, frame.max(1) as u16, stop);
 
     Ok(())
 }

tests/tests/regression_tests.rs

@@ -343,6 +343,7 @@ swf_tests! {
     (as3_get_qualified_super_class_name, "avm2/get_qualified_super_class_name", 1),
     (as3_get_timer, "avm2/get_timer", 1),
     (as3_getouterscope, "avm2/getouterscope", 1),
+    (as3_goto_methods, "avm2/goto_methods", 1),
     (as3_greaterequals, "avm2/greaterequals", 1),
     (as3_greaterthan, "avm2/greaterthan", 1),
     (as3_has_own_property, "avm2/has_own_property", 1),

tests/tests/swfs/avm2/goto_methods/output.txt

@@ -0,0 +1,56 @@
+// clip.gotoAndStop(999)
+3
+// clip.gotoAndStop(0)
+1
+// clip.gotoAndPlay(1)
+1
+// clip.gotoAndPlay(2)
+2
+// clip.gotoAndPlay(0x80000000)
+3
+// clip.gotoAndPlay(2)
+2
+// clip.gotoAndPlay(0x100000002)
+3
+// clip.gotoAndPlay(2)
+2
+// clip.gotoAndPlay(-0x80000000)
+3
+// clip.gotoAndPlay(2)
+2
+// clip.gotoAndPlay(-0x7FFFFFFF)
+1
+// clip.gotoAndPlay(2)
+2
+// clip.gotoAndPlay(-99999999999999999999)
+3
+// clip.gotoAndPlay(2)
+2
+// clip.gotoAndPlay('3 ')
+3
+// clip.gotoAndPlay(2)
+2
+// clip.gotoAndPlay('-99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999')
+3
+// clip.gotoAndPlay(Number(2.0))
+2
+// clip.gotoAndPlay(Number(-99.0))
+1
+// clip.gotoAndPlay(2)
+2
+// clip.gotoAndPlay(-99)
+1
+// clip.prevFrame()
+1
+// clip.prevFrame()
+1
+// clip.prevFrame()
+1
+// clip.gotoAndStop('TheFrame')
+2
+// clip.nextFrame()
+3
+// clip.nextFrame()
+3
+// clip.gotoAndStop({toString: function() { return 'TheFrame' }})
+2