Tooltips/Highlight/Select incorrect when AREA shape attribute is missing or its value is non-conforming/empty

[RWAP]

For some reason, if you have ModPagespeed enabled, with the elide_attributes filter enabled, this impacts on ImageMapster.

I have a site which uses two images to show a highlighted area onclick or on mouseover.

This works fine under ImageMapster.

However, if elide_attributes is enabled - the highlighted area is not shown in Google Chrome or FIrefox (IE10 still shows it successfully).

See https://developers.google.com/speed/pagespeed/module/filter-attribute-elide

Even more oddly - it seemed to work after a while on Firefox when using 2 GIF images, but not when using two PNG images.

No errors are shown in Firebug, so it is difficult to guess which stripped attribute is causing the problem!

[RWAP]

I wonder whether this may be because the elide_attributes filter removes shape="rect" from the area map definitions - this is of course the browser default shape, so should be assumed where this attribute is not present

[techfg]

@RWAP -

Thank you for reporting this, apologies for the delayed reply!

Your analysis is correct - there is a bug in IM that does not account for shape attributes that have non-confirming/missing values. In your situation, since elide_attributes is "removing" the shape="rect" because its the default, when IM parses the HTML, it should apply rect as the default shape since its missing according to the AREA element spec.

There are actually a few places where IM doesn't currently account for missing/non-confirming values so I've adjusted the title of this issue to reflect as much and marked it as a bug.

Fix will be forthcoming in next release, thank you again for reporting this!