diff --git a/mongoose.c b/mongoose.c
index 3d7d715d..9ee2eed3 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -1683,7 +1683,7 @@ void mg_http_delete_chunk(struct mg_connection *c, struct mg_http_message *hm) {
 static void http_cb(struct mg_connection *c, int ev, void *evd, void *fnd) {
   if (ev == MG_EV_READ || ev == MG_EV_CLOSE) {
     struct mg_http_message hm;
-    for (;;) {
+    while (c->recv.buf != NULL && c->recv.len > 0) {
       int n = mg_http_parse((char *) c->recv.buf, c->recv.len, &hm);
       bool is_chunked = n > 0 && mg_is_chunked(&hm);
       if (ev == MG_EV_CLOSE) {
@@ -4291,8 +4291,9 @@ static size_t mg_nce(const char *s, size_t n, size_t ofs, size_t *koff,
 }
 
 bool mg_commalist(struct mg_str *s, struct mg_str *k, struct mg_str *v) {
-  size_t koff = 0, klen = 0, voff = 0, vlen = 0;
-  size_t off = mg_nce(s->ptr, s->len, 0, &koff, &klen, &voff, &vlen);
+  size_t koff = 0, klen = 0, voff = 0, vlen = 0, off = 0;
+  if (s->ptr == NULL || s->len == 0) return 0;
+  off = mg_nce(s->ptr, s->len, 0, &koff, &klen, &voff, &vlen);
   if (k != NULL) *k = mg_str_n(s->ptr + koff, klen);
   if (v != NULL) *v = mg_str_n(s->ptr + voff, vlen);
   *s = mg_str_n(s->ptr + off, s->len - off);
diff --git a/src/http.c b/src/http.c
index f0f4e8ec..33fd94e2 100644
--- a/src/http.c
+++ b/src/http.c
@@ -919,7 +919,7 @@ void mg_http_delete_chunk(struct mg_connection *c, struct mg_http_message *hm) {
 static void http_cb(struct mg_connection *c, int ev, void *evd, void *fnd) {
   if (ev == MG_EV_READ || ev == MG_EV_CLOSE) {
     struct mg_http_message hm;
-    for (;;) {
+    while (c->recv.buf != NULL && c->recv.len > 0) {
       int n = mg_http_parse((char *) c->recv.buf, c->recv.len, &hm);
       bool is_chunked = n > 0 && mg_is_chunked(&hm);
       if (ev == MG_EV_CLOSE) {
diff --git a/src/util.c b/src/util.c
index b948bebe..8981a5a6 100644
--- a/src/util.c
+++ b/src/util.c
@@ -113,8 +113,9 @@ static size_t mg_nce(const char *s, size_t n, size_t ofs, size_t *koff,
 }
 
 bool mg_commalist(struct mg_str *s, struct mg_str *k, struct mg_str *v) {
-  size_t koff = 0, klen = 0, voff = 0, vlen = 0;
-  size_t off = mg_nce(s->ptr, s->len, 0, &koff, &klen, &voff, &vlen);
+  size_t koff = 0, klen = 0, voff = 0, vlen = 0, off = 0;
+  if (s->ptr == NULL || s->len == 0) return 0;
+  off = mg_nce(s->ptr, s->len, 0, &koff, &klen, &voff, &vlen);
   if (k != NULL) *k = mg_str_n(s->ptr + koff, klen);
   if (v != NULL) *v = mg_str_n(s->ptr + voff, vlen);
   *s = mg_str_n(s->ptr + off, s->len - off);