I recently implemented HTML5's IDL definition for <marquee> in WebKit (https://webkit.org/b/49786) and noticed a few differences between how HTML5 specs marquee and how IE implements it. I noticed the following two discrepancies:
1) For scrollAmount, scrollDelay and loop, IE does not allow the content attribute value to contain trailing non-numeric characters, although such characters are allowed according to HTML5's "rules for parsing non-negative integers" (section 2.5.4.1). IE will return the default value for these attributes if non-numeric characters are encountered, but HTML5 says to parse up to the first non-number and return that value. 2) For scrollAmount, scrollDelay and loop, if a value is specified that exceeds 2^31-1, IE will return 2^31-1. HTML5 says that for reflected unsigned longs, if a value is larger than 2^31-1, the default value, or 0, should be returned (section 2.8.1). Perhaps these differences aren't specific to <marquee> but rather true for all unsigned content attributes in IE. In any event, I wanted to point out the differences in these edge cases and ask if they are intentional or not. I'd be happy to file a bug if that's the correct thing to do. Thanks, Andy
