Add error check for iobuf allocation

src/iobuf.c

@@ -3,7 +3,8 @@
 
 #include <string.h>
 
-void mg_iobuf_resize(struct mg_iobuf *io, size_t new_size) {
+int mg_iobuf_resize(struct mg_iobuf *io, size_t new_size) {
+  int ok = 1;
   if (new_size == 0) {
     free(io->buf);
     io->buf = NULL;
@@ -18,16 +19,20 @@ void mg_iobuf_resize(struct mg_iobuf *io, size_t new_size) {
       io->buf = (unsigned char *) p;
       io->size = new_size;
     } else {
+      ok = 0;
       LOG(LL_ERROR,
           ("%lu->%lu", (unsigned long) io->size, (unsigned long) new_size));
     }
   }
+  return ok;
 }
 
-void mg_iobuf_init(struct mg_iobuf *io, size_t size) {
+int mg_iobuf_init(struct mg_iobuf *io, size_t size) {
+  int ok = 1;
   io->buf = NULL;
   io->len = io->size = 0;
-  if (size > 0) mg_iobuf_resize(io, size);
+  if (size > 0) ok = mg_iobuf_resize(io, size);
+  return ok;
 }
 
 size_t mg_iobuf_append(struct mg_iobuf *io, const void *buf, size_t len,

src/iobuf.h

@@ -7,8 +7,8 @@ struct mg_iobuf {
   size_t size, len;
 };
 
-void mg_iobuf_init(struct mg_iobuf *, size_t);
-void mg_iobuf_resize(struct mg_iobuf *, size_t);
+int mg_iobuf_init(struct mg_iobuf *, size_t);
+int mg_iobuf_resize(struct mg_iobuf *, size_t);
 void mg_iobuf_free(struct mg_iobuf *);
 size_t mg_iobuf_append(struct mg_iobuf *, const void *, size_t, size_t);
 size_t mg_iobuf_delete(struct mg_iobuf *, size_t);

src/sock.c

@@ -161,6 +161,7 @@ int mg_send(struct mg_connection *c, const void *buf, size_t len) {
   int fail, n = c->is_udp
                     ? ll_write(c, buf, (SOCKET) len, &fail)
                     : (int) mg_iobuf_append(&c->send, buf, len, MG_IO_SIZE);
+  if (len > 0 && n == 0) fail = 1;
   return n;
 }
 
@@ -235,8 +236,9 @@ static void read_conn(struct mg_connection *c,
   // NOTE(lsm): do only one iteration of reads, cause some systems
   // (e.g. FreeRTOS stack) return 0 instead of -1/EWOULDBLOCK when no data
   if (c->recv.size - c->recv.len < MG_IO_SIZE &&
-      c->recv.size < MG_MAX_RECV_BUF_SIZE) {
-    mg_iobuf_resize(&c->recv, c->recv.size + MG_IO_SIZE);
+      c->recv.size < MG_MAX_RECV_BUF_SIZE &&
+      !mg_iobuf_resize(&c->recv, c->recv.size + MG_IO_SIZE)) {
+    c->is_closing = 1;
   }
   buf = c->recv.buf + c->recv.len;
   len = (int) (c->recv.size - c->recv.len);