The compiler complains and fails trying to compile `algodefs.c` unless `--std=gnu99` is added on the command-line to make.  8 other files in that directory were modified by the specified commit (see "Environment"), which actually removed the correct code and made it less correct. 

```
algodefs.c:200:2: note: use option -std=c99 or -std=gnu99 to compile your code
algodefs.c: In function 'zbx_isqrt32':
algodefs.c:231:2: error: 'for' loop initial declarations are only allowed in C99 mode
  for (int i = 0; i < 16; i++)

```

Note: `--std=c99` fails BSD-specific parts of the code.