Without this fix, ivlh_textio was failing at step 11 where the time is read from the file. This was because clang happens to put period directly after the units buffer on the stack. sscanf writes the terminating NUL overwriting the low byte of period, which is 100, so it returns 0.
Example clang warning fixed:
warning: 'sscanf' may overflow; destination buffer in argument 4 has size 2, but the corresponding specifier may require size 3 [-Wfortify-source]
Jevin Sweval
Cary R
Martin Whitaker
Maciej Suminski