ustream: return NULL in ustream_get_read_buf if there's a buffer, but no data

[project/libubox.git] / ustream.c

diff --git a/ustream.c b/ustream.c
index ed4fbb3..fd43395 100644 (file)
--- a/ustream.c
+++ b/ustream.c
@@ -37,6 +37,7 @@ static void ustream_init_buf(struct ustream_buf *buf, int len)
 
 static void ustream_add_buf(struct ustream_buf_list *l, struct ustream_buf *buf)
 {
+       l->buffers++;
        if (!l->tail)
                l->head = buf;
        else
@@ -104,7 +105,8 @@ static void ustream_state_change_cb(struct uloop_timeout *t)
 
        if (s->write_error)
                ustream_free_buffers(&s->w);
-       s->notify_state(s);
+       if (s->notify_state)
+               s->notify_state(s);
 }
 
 void ustream_init_defaults(struct ustream *s)
@@ -309,15 +311,13 @@ void ustream_fill_read(struct ustream *s, int len)
 
 char *ustream_get_read_buf(struct ustream *s, int *buflen)
 {
-       char *data;
-       int len;
+       char *data = NULL;
+       int len = 0;
 
        if (s->r.head) {
                len = s->r.head->tail - s->r.head->data;
-               data = s->r.head->data;
-       } else {
-               len = 0;
-               data = NULL;
+               if (len > 0)
+                       data = s->r.head->data;
        }
 
        if (buflen)
@@ -328,8 +328,9 @@ char *ustream_get_read_buf(struct ustream *s, int *buflen)
 
 static void ustream_write_error(struct ustream *s)
 {
+       if (!s->write_error)
+               ustream_state_change(s);
        s->write_error = true;
-       ustream_state_change(s);
 }
 
 bool ustream_write_pending(struct ustream *s)
@@ -340,7 +341,7 @@ bool ustream_write_pending(struct ustream *s)
        if (s->write_error)
                return false;
 
-       while (buf) {
+       while (buf && s->w.data_bytes) {
                struct ustream_buf *next = buf->next;
                int maxlen = buf->tail - buf->data;
 
@@ -434,6 +435,9 @@ int ustream_vprintf(struct ustream *s, const char *format, va_list arg)
        va_list arg2;
        int wr, maxlen, buflen;
 
+       if (s->write_error)
+               return 0;
+
        if (!l->data_bytes) {
                buf = alloca(MAX_STACK_BUFLEN);
                va_copy(arg2, arg);
@@ -492,6 +496,9 @@ int ustream_printf(struct ustream *s, const char *format, ...)
        va_list arg;
        int ret;
 
+       if (s->write_error)
+               return 0;
+
        va_start(arg, format);
        ret = ustream_vprintf(s, format, arg);
        va_end(arg);