diff --git a/common/base-str.cpp b/common/base-str.cpp
index 0566821420e..2439c2931a1 100644
--- a/common/base-str.cpp
+++ b/common/base-str.cpp
@@ -731,6 +731,8 @@ TEMPLATE void BASESTRING::trim() {
 #endif
 
 TEMPLATE void BASESTRING::assignAppend(value_type c) {
+	if (c == 0)
+		return;
 	ensureCapacity(_size + 1, true);
 
 	_str[_size++] = c;