Reading from a pipe is messed up #14
Description
I tried reading output from stderr from a process, and it gets all messed up. It seems the length of the buffer returned is correct, but only the first couple of hundred bytes are filled, the rest are zeroes.
Looking at the code, it seems that read_atmost_n does not handle partial reads correctly. Changing this line to the following seems to fix this.
int read_bytes = read(fd, buf + rbytes, read_upto - rbytes)
On a related note, I suspect that if read_all resizes the buffer and causes a realloc, then the buffer variable might become invalid.