This page is a snapshot from the LWG issues list, see the Library Active Issues List for more information and the meaning of TC1 status.
Section: 188.8.131.52.3 [facet.num.get.virtuals] Status: TC1 Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2016-02-10
Priority: Not Prioritized
View all other issues in [facet.num.get.virtuals].
View all issues with TC1 status.
The table in paragraph 7 for the length modifier does not list the length modifier l to be applied if the type is double. Thus, the standard asks the implementation to do undefined things when using scanf() (the missing length modifier for scanf() when scanning doubles is actually a problem I found quite often in production code, too).
In 184.108.40.206.3 [facet.num.get.virtuals], paragraph 7, add a row in the Length Modifier table to say that for double a length modifier l is to be used.
The standard makes an embarrassing beginner's mistake.