static void
free_headings (const struct pivot_axis *axis, char ***headings)
{
+ if (!headings)
+ return;
for (size_t i = 0; i < axis->label_depth; i++)
{
for (size_t j = 0; j < axis->extent; j++)
{
if (x)
fputs ("; ", stdout);
- if (column_headings[y][x])
+ if (column_headings && column_headings[y] && column_headings[y][x])
fputs (column_headings[y][x], stdout);
}
putchar ('\n');