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_pgsql/pgsql_driver.c b/ext/pdo_pgsql/pgsql_driver.c
index 5aae5d0a38..15b2bd16c9 100644
--- a/ext/pdo_pgsql/pgsql_driver.c
+++ b/ext/pdo_pgsql/pgsql_driver.c
@@ -124,13 +124,13 @@ static int pdo_pgsql_fetch_error_func(pdo_dbh_t *dbh, pdo_stmt_t *stmt, zval *in
 /* }}} */
 
 /* {{{ pdo_pgsql_create_lob_stream */
-static size_t pgsql_lob_write(php_stream *stream, const char *buf, size_t count)
+static ssize_t pgsql_lob_write(php_stream *stream, const char *buf, size_t count)
 {
 	struct pdo_pgsql_lob_self *self = (struct pdo_pgsql_lob_self*)stream->abstract;
 	return lo_write(self->conn, self->lfd, (char*)buf, count);
 }
 
-static size_t pgsql_lob_read(php_stream *stream, char *buf, size_t count)
+static ssize_t pgsql_lob_read(php_stream *stream, char *buf, size_t count)
 {
 	struct pdo_pgsql_lob_self *self = (struct pdo_pgsql_lob_self*)stream->abstract;
 	return lo_read(self->conn, self->lfd, buf, count);