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, 1 insertions, 1 deletions

diff --git a/ext/standard/md5.c b/ext/standard/md5.c
index d6ec2ffa66..5bf29be286 100644
--- a/ext/standard/md5.c
+++ b/ext/standard/md5.c
@@ -78,7 +78,7 @@ PHP_NAMED_FUNCTION(php_if_md5_file)
 	unsigned char buf[1024];
 	unsigned char digest[16];
 	PHP_MD5_CTX   context;
-	size_t           n;
+	ssize_t       n;
 	php_stream    *stream;
 
 	ZEND_PARSE_PARAMETERS_START(1, 2)