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.

2 files changed, 6 insertions, 6 deletions

diff --git a/ext/pgsql/pgsql.c b/ext/pgsql/pgsql.c
index 967eb05155..9f51256ac5 100644
--- a/ext/pgsql/pgsql.c
+++ b/ext/pgsql/pgsql.c
@@ -5372,15 +5372,15 @@ PHP_FUNCTION(pg_get_pid)
 }
 /* }}} */
 
-static size_t php_pgsql_fd_write(php_stream *stream, const char *buf, size_t count) /* {{{ */
+static ssize_t php_pgsql_fd_write(php_stream *stream, const char *buf, size_t count) /* {{{ */
 {
-	return 0;
+	return -1;
 }
 /* }}} */
 
-static size_t php_pgsql_fd_read(php_stream *stream, char *buf, size_t count) /* {{{ */
+static ssize_t php_pgsql_fd_read(php_stream *stream, char *buf, size_t count) /* {{{ */
 {
-	return 0;
+	return -1;
 }
 /* }}} */
 
diff --git a/ext/pgsql/php_pgsql.h b/ext/pgsql/php_pgsql.h
index 0294ea10a9..cecd2cc95b 100644
--- a/ext/pgsql/php_pgsql.h
+++ b/ext/pgsql/php_pgsql.h
@@ -225,8 +225,8 @@ static void php_pgsql_get_field_info(INTERNAL_FUNCTION_PARAMETERS, int entry_typ
 static void php_pgsql_data_info(INTERNAL_FUNCTION_PARAMETERS, int entry_type);
 static void php_pgsql_do_async(INTERNAL_FUNCTION_PARAMETERS,int entry_type);
 
-static size_t php_pgsql_fd_write(php_stream *stream, const char *buf, size_t count);
-static size_t php_pgsql_fd_read(php_stream *stream, char *buf, size_t count);
+static ssize_t php_pgsql_fd_write(php_stream *stream, const char *buf, size_t count);
+static ssize_t php_pgsql_fd_read(php_stream *stream, char *buf, size_t count);
 static int php_pgsql_fd_close(php_stream *stream, int close_handle);
 static int php_pgsql_fd_flush(php_stream *stream);
 static int php_pgsql_fd_set_option(php_stream *stream, int option, int value, void *ptrparam);