Syntax error with #if and designated initializer

[chrchr-github]

From the forum: https://sourceforge.net/p/cppcheck/discussion/general/thread/2cc604d687

struct S { int i; };
struct S s = {
#if 1
            .i = 1,
#endif
};

bar.cpp:3:0: error: Syntax error in #if [preprocessorErrorDirective]
#if 1
^

The tokens 1 and . are combined.