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/pdo_oci/oci_statement.c b/ext/pdo_oci/oci_statement.c
index b983f20116..5d01ae1dab 100644
--- a/ext/pdo_oci/oci_statement.c
+++ b/ext/pdo_oci/oci_statement.c
@@ -634,7 +634,7 @@ struct oci_lob_self {
 	ub4 offset;
 };
 
-static size_t oci_blob_write(php_stream *stream, const char *buf, size_t count)
+static ssize_t oci_blob_write(php_stream *stream, const char *buf, size_t count)
 {
 	struct oci_lob_self *self = (struct oci_lob_self*)stream->abstract;
 	ub4 amt;
@@ -647,7 +647,7 @@ static size_t oci_blob_write(php_stream *stream, const char *buf, size_t count)
 		NULL, NULL, 0, SQLCS_IMPLICIT);
 
 	if (r != OCI_SUCCESS) {
-		return (size_t)-1;
+		return (ssize_t)-1;
 	}
 
 	self->offset += amt;