diff -r db24a4cb8139 -r ca682d9d8db5 src/hotspot/share/classfile/classFileParser.cpp
--- a/src/hotspot/share/classfile/classFileParser.cpp	Thu Feb 21 15:17:42 2019 -0800
+++ b/src/hotspot/share/classfile/classFileParser.cpp	Thu Feb 21 16:56:06 2019 -0800
@@ -5743,16 +5743,13 @@
     ClassLoader::package_from_name(unsafe_anonymous_host->name()->as_C_string(), NULL);
 
   if (host_pkg_name != NULL) {
-    size_t host_pkg_len = strlen(host_pkg_name);
+    int host_pkg_len = (int)strlen(host_pkg_name);
     int class_name_len = _class_name->utf8_length();
-    char* new_anon_name =
-      NEW_RESOURCE_ARRAY(char, host_pkg_len + 1 + class_name_len);
-    // Copy host package name and trailing /.
-    strncpy(new_anon_name, host_pkg_name, host_pkg_len);
-    new_anon_name[host_pkg_len] = '/';
-    // Append unsafe anonymous class name. The unsafe anonymous class name can contain odd
-    // characters.  So, do a strncpy instead of using sprintf("%s...").
-    strncpy(new_anon_name + host_pkg_len + 1, (char *)_class_name->base(), class_name_len);
+    int symbol_len = host_pkg_len + 1 + class_name_len;
+    char* new_anon_name = NEW_RESOURCE_ARRAY(char, symbol_len + 1);
+    int n = snprintf(new_anon_name, symbol_len + 1, "%s/%.*s",
+                     host_pkg_name, class_name_len, _class_name->base());
+    assert(n == symbol_len, "Unexpected number of characters in string");
 
     // Decrement old _class_name to avoid leaking.
     _class_name->decrement_refcount();
@@ -5761,9 +5758,7 @@
     // The new class name is created with a refcount of one. When installed into the InstanceKlass,
     // it'll be two and when the ClassFileParser destructor runs, it'll go back to one and get deleted
     // when the class is unloaded.
-    _class_name = SymbolTable::new_symbol(new_anon_name,
-                                          (int)host_pkg_len + 1 + class_name_len,
-                                          CHECK);
+    _class_name = SymbolTable::new_symbol(new_anon_name, symbol_len, CHECK);
   }
 }