Commit b61e8b81 authored Aug 07, 2012 by Maxime Larocque Committed by Daniel Stenberg Aug 07, 2012

Curl_socket_check: fix return code for timeout

We found a problem with ftp transfer using libcurl (7.23 and 7.25)
inside an application which is receiving unix signals (SIGUSR1,
SIGUSR2...) almost continuously. (Linux 2.4, PowerPC, HAVE_POLL_FINE
defined).

Curl_socket_check() uses poll() to wait for the socket, and retries it
when a signal is received (EINTR). However, if a signal is received and
it also happens that the timeout has been reached, Curl_socket_check()
returns -1 instead of 0 (indicating an error instead of a timeout).

In our case, the result is an aborted connection even before the ftp
banner is received from the server, and a return value of
CURLE_OUT_OF_MEMORY from curl_easy_perform() (Curl_pp_multi_statemach(),
in pingpong.c, actually returns OOM if Curl_socket_check() fails :-)
Funny to debug on a system on which OOM is a possible cause).

Bug: http://curl.haxx.se/mail/lib-2012-07/0122.html

parent 77f72aa6

lib/select.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -221,9 +221,11 @@ int Curl_socket_check(curl_socket_t readfd0, /* two sockets to read from */
		break;
		if(timeout_ms > 0) {
		pending_ms = (int)(timeout_ms - elapsed_ms);
		if(pending_ms <= 0)
		if(pending_ms <= 0) {
		r = 0; /* Simulate a "call timed out" case */
		break;
		}
		}
		} while(r == -1);

		if(r < 0)