5 files changed, 36 insertions, 23 deletions
diff --git a/src/platform/posix/posix_alloc.c b/src/platform/posix/posix_alloc.c
index f4b0245c..f0847408 100644
--- a/src/platform/posix/posix_alloc.c
+++ b/src/platform/posix/posix_alloc.c
@@ -17,13 +17,13 @@
 void *
 nni_alloc(size_t sz)
 {
-	return (malloc(sz));
+	return (sz > 0 ? malloc(sz) : NULL);
 }
 
 void *
 nni_zalloc(size_t sz)
 {
-	return (calloc(1, sz));
+	return (sz > 0 ? calloc(1, sz) : NULL);
 }
 
 void
diff --git a/src/platform/posix/posix_file.c b/src/platform/posix/posix_file.c
index b21c0509..5d918d6b 100644
--- a/src/platform/posix/posix_file.c
+++ b/src/platform/posix/posix_file.c
@@ -115,14 +115,18 @@ nni_plat_file_get(const char *name, void **datap, size_t *lenp)
 	}
 
 	len = st.st_size;
-	if ((data = nni_alloc(len)) == NULL) {
-		rv = NNG_ENOMEM;
-		goto done;
-	}
-	if (fread(data, 1, len, f) != len) {
-		rv = nni_plat_errno(errno);
-		nni_free(data, len);
-		goto done;
+	if (len > 0) {
+		if ((data = nni_alloc(len)) == NULL) {
+			rv = NNG_ENOMEM;
+			goto done;
+		}
+		if (fread(data, 1, len, f) != len) {
+			rv = nni_plat_errno(errno);
+			nni_free(data, len);
+			goto done;
+		}
+	} else {
+		data = NULL;
 	}
 	*datap = data;
 	*lenp  = len;
diff --git a/src/platform/windows/win_file.c b/src/platform/windows/win_file.c
index 3b6461a6..47bb87af 100644
--- a/src/platform/windows/win_file.c
+++ b/src/platform/windows/win_file.c
@@ -136,14 +136,19 @@ nni_plat_file_get(const char *name, void **datap, size_t *lenp)
 		rv = nni_win_error(GetLastError());
 		goto done;
 	}
-	if ((data = nni_alloc((size_t) sz)) == NULL) {
-		rv = NNG_ENOMEM;
-		goto done;
-	}
-	if (!ReadFile(h, data, sz, &nread, NULL)) {
-		rv = nni_win_error(GetLastError());
-		nni_free(data, sz);
-		goto done;
+	if (sz > 0) {
+		if ((data = nni_alloc((size_t) sz)) == NULL) {
+			rv = NNG_ENOMEM;
+			goto done;
+		}
+		if (!ReadFile(h, data, sz, &nread, NULL)) {
+			rv = nni_win_error(GetLastError());
+			nni_free(data, sz);
+			goto done;
+		}
+	} else {
+		data  = NULL;
+		nread = 0;
 	}
 
 	// We can get a short read, indicating end of file.  We return
diff --git a/src/platform/windows/win_thread.c b/src/platform/windows/win_thread.c
index d6363207..3b4e63bc 100644
--- a/src/platform/windows/win_thread.c
+++ b/src/platform/windows/win_thread.c
@@ -19,13 +19,13 @@
 void *
 nni_alloc(size_t sz)
 {
-	return (malloc(sz));
+	return (sz > 0 ? malloc(sz) : NULL);
 }
 
 void *
 nni_zalloc(size_t sz)
 {
-	return (calloc(1, sz));
+	return (sz > 0 ? calloc(1, sz) : NULL);
 }
 
 void
diff --git a/src/protocol/pubsub0/sub.c b/src/protocol/pubsub0/sub.c
index cb6d781f..aeccfd25 100644
--- a/src/protocol/pubsub0/sub.c
+++ b/src/protocol/pubsub0/sub.c
@@ -228,9 +228,13 @@ sub0_subscribe(void *arg, const void *buf, size_t sz, nni_opt_type t)
 		nni_mtx_unlock(&s->lk);
 		return (NNG_ENOMEM);
 	}
-	if ((newtopic->buf = nni_alloc(sz)) == NULL) {
-		nni_mtx_unlock(&s->lk);
-		return (NNG_ENOMEM);
+	if (sz > 0) {
+		if ((newtopic->buf = nni_alloc(sz)) == NULL) {
+			nni_mtx_unlock(&s->lk);
+			return (NNG_ENOMEM);
+		}
+	} else {
+		newtopic->buf = NULL;
 	}
 	NNI_LIST_NODE_INIT(&newtopic->node);
 	newtopic->len = sz;