[Bug]: different behavior when calling link.attr with object vs string

What happened?

I have my command manager subscribed to stack:push events. Playing around with .attr() I found out that it will trigger a stack:push events depending on what parameters I pass to it.

Example:

const link = new dia.standard.Link();
const cm = new dia.CommandManager(...);

cm.on("stack:push", (commands, opt) => {
  console.log(commands);
});

link.attr("line/stroke", "red");  // <-- this WON'T trigger stack:push


link.attr({                       // <-- this WILL trigger stack:push
  line: {  stroke: "red" },  
});

I tried debugging the internals of Joint / Backbone and it seems that, by the time Backbone’s .set() method is called, it’s _pending flag has a different value. This then causes line 540 (backbone.js) to be called.

I’m not really sure if I’m doing something I’m not supposed to or if this is a bug.

Also, this seems to be happening only with Links.

Version

3.6.2

What browsers are you seeing the problem on?

Chrome

What operating system are you seeing the problem on?

Mac

[alexandernst]

I just checked the PR. This will be very useful without any doubt! Thank you for the fast patch! 🙏

[kumilingus]

Fixed in #1946 .