The previous behavior had an oversight: if you tried to set a variable with the same name as an in-scope property, it would always try to overwrite that property. This can fail silently and doesn't match with Flash Player behavior. Now, an attempt to overwrite a read-only property is instead correctly rejected so that it can be defined in local scope.
This type explicitly signals if an immediate value is to be returned, if a value is to be returned on the stack, or if no return value is to be generated. Holders of a `ReturnValue` can also use `and_then` to schedule a `StackContinuation` to be executed when and if that value is ready.
`StackContinuations` now yield `ReturnValues` as well, so they have a moderate level of composability. For example, if you need to get a property from an object and push it on the stack, you can return the result of calling `get` directly and the machinery ensures it eventually gets there.
This involved yet another macro, `and_then!`, to avoid a ridiculous amount of duplicate code. It calls a continuation whenever it's value is ready, even if the value resolved on the Rust stack.
`locals_into_form_values` does not currently support this. It skips any property that does not resolve on the Rust stack. Future work is required to resolve this.
This involves the use of a "stack continuation" system. Due to previous lifetime issues with using closures directly (see `8ea6c6234dba925ec5fbc61502627fb62b05916c`), we instead use a macro that constructs a `Collect`able type holding the things the continuation needs to continue working with. The syntax is largely similar to Rust closures but with the addition of an explicit list of bound variables, all of which must be `Collect`.
Generally there is one SoundStreamBlock per frame in a MovieClip.
However, if there are gaps between stream sounds, the stream must
stop and then pick up when the next block is encountered.
TODO: Sometimes Flash will do weird stuff and export a stream that
is plainly out of sync if there are gaps between sounds (the old
trick was to put a silent stream across the entire timeline to fix
this). This happens when the streams are too close together with
MP3 encoding. Investigate this more.
This pushes an extra `undefined` onto the stack to fix underflow in AS2 interface declarations.
It is currently unknown if this is a miscompilation or if some other value is supposed to be there.
# Conflicts:
# core/src/avm1.rs
# core/src/avm1/object.rs
The premultiplied alpha was not properly considered when there was
a color transform on a bitmap. Now the shader unmultiplies the
alpha before applying the color transform, and the remultiplies it.
Goto forward that did a replace was not replacing the previous child.
TODO: Figure out how to write a regression test for this; will
need a special test harness probably because this only happens with
Graphics, not MovieClips, so we can't attach AS to them to get
trace output.
When a stream sound uses ADPCM compression, the ADPCM header is
included in each SoundStreamBlock (as opposed to stream sounds
in the other formats). This header wasn't being parsed, resulting
in corrupted audio (see https://homestarrunner.com/main12.swf).
Gotos now goto the specified frames immediately as opposed to
queuing. Actions on the new frame will still be queued,
and are executed after any current actions are completed.
Mike Welsh