Description:
------------
file     ext/standard/file.c
line     1028


buf = ecalloc(len + 1, sizeof(char));
		if (php_stream_get_line(stream, buf, len, &line_len) == NULL) {
			goto exit_failed;
		}


here doesn't check the availablity of 'buf', so if ecalloc doesn't calloc a memory, it will return NULL, it will cause some problem

Reproduce code:
---------------
$fp=fopen("1.txt", "r");
fgets($fp, 2147483640);

on some platform, when ecalloc failed, it will return NULL, so segmentation fault will prompt. 


the same as fread function