Report errors from stream read and write operations

The php_stream_read() and php_stream_write() functions now return
an ssize_t value, with negative results indicating failure. Functions
like fread() and fwrite() will return false in that case.

As a special case, EWOULDBLOCK and EAGAIN on non-blocking streams
should not be regarded as error conditions, and be reported as
successful zero-length reads/writes instead. The handling of EINTR
remains unclear and is internally inconsistent (e.g. some code-paths
will automatically retry on EINTR, while some won't).

I'm landing this now to make sure the stream wrapper ops API changes
make it into 7.4 -- however, if the user-facing changes turn out to
be problematic we have the option of clamping negative returns to
zero in php_stream_read() and php_stream_write() to restore the
old behavior in a relatively non-intrusive manner.

1 files changed, 2 insertions, 2 deletions

diff --git a/ext/curl/interface.c b/ext/curl/interface.c
index 6b42ddafa6..6a25359597 100644
--- a/ext/curl/interface.c
+++ b/ext/curl/interface.c
@@ -2133,9 +2133,9 @@ PHP_FUNCTION(curl_copy_handle)
 static size_t read_cb(char *buffer, size_t size, size_t nitems, void *arg) /* {{{ */
 {
 	php_stream *stream = (php_stream *) arg;
-	size_t numread = php_stream_read(stream, buffer, nitems * size);
+	ssize_t numread = php_stream_read(stream, buffer, nitems * size);
 
-	if (numread == (size_t)-1) {
+	if (numread < 0) {
 		return CURL_READFUNC_ABORT;
 	}
 	return numread;