only mmap a file if its size is larger than 0 bytes

src/asset/asset.c

@@ -96,6 +96,7 @@ assetCtor(void * _this, va_list * params)
 		this->nmime_type = 0;
 	}
 
+	if (0 < this->size) {
 		this->data = mmap(
 				NULL, this->size, PROT_READ, MAP_PRIVATE, this->handle, 0);
 
@@ -103,6 +104,7 @@ assetCtor(void * _this, va_list * params)
 			close(this->handle);
 			return -1;
 		}
+	}
 
 	this->ref_count = 1;