Bug#902630: libtinfo6: tiparm("") returns NULL

[Jakub Wilk]

Package: libtinfo6
Version: 6.1+20180210-4

I'm not sure what are the exact circumstances, but tiparm("") sometimes 
returns NULL instead of empty string:

  $ make test-tiparm LDLIBS=-ltinfo
  cc     test-tiparm.c  -ltinfo -o test-tiparm

  $ ./test-tiparm
  tiparm("") = NULL
  tiparm("foo") = "foo"
  tiparm("") = ""


-- System Information:
Architecture: i386

Versions of packages libtinfo6 depends on:
ii  libc6  2.27-3

--
Jakub Wilk
#include <stdio.h>

#include <term.h>

void test_tiparm(const char *s)
{
	const char *t = tiparm(s);
	printf("tiparm(\"%s\") = ", s);
	if (t)
		printf("\"%s\"", t);
	else
		printf("NULL");
	printf("\n");
}

int main(int argc, char **argv)
{
	setupterm(NULL, 1, NULL);
	test_tiparm("");
	test_tiparm("foo");
	test_tiparm("");
	return 0;
}