ASAN on windows empty string literal false positive

I am trying to reproduce this in a trivial project but haven't been able to yet.

ASAN (windows x64, llvm release 8.0.0) seems to be complaining about me accessing the null terminating byte of the empty string literal

in main.cpp:

int
main(int argc, char **argv)
{
	{
		db_strdup("", "file", 12);
	}
...

in malloc.cpp:

char *
db_strdup(const char *str, const char *file, int line)
{
	int len = strlen(str);
	char *newStr = (char *)db_malloc(len + 1, file, line);
	strcpy(newStr, str);
	return newStr;
}

and asan is complaining on the strlen(str) call.

These excerpts from the error message seem to describe fine behavior:

READ of size 1 at 0x7ff710b1fe80 thread T0
0x7ff710b1fe80 is located 0 bytes inside of global variable '' defined in 'bdescribed.cpp:12:34' (0x7ff710b1fe80) of size 1

Is this an issue where the shadow bytes forgot to mark the null terminating byte as readable?

asan_issue.txt

Start by reproducing the Windows x64 LLVM 8.0.0 report from the snippets in main.cpp and malloc.cpp, then inspect asan_issue.txt alongside the strlen call. Done means determining whether the empty string literal access is a false positive and identifying the relevant AddressSanitizer behavior or fix.