1 files changed, 9 insertions, 6 deletions
diff --git a/zen/string_base.h b/zen/string_base.h
index 3afa66c6..b5e45c0e 100755
--- a/zen/string_base.h
+++ b/zen/string_base.h
@@ -264,8 +264,8 @@ public:
     void push_back(Char val) { operator+=(val); } //STL access
     void pop_back();
 
-    Zbase& operator=(const Zbase& str);
     Zbase& operator=(Zbase&& tmp) noexcept;
+    Zbase& operator=(const Zbase& str);
     Zbase& operator=(const Char* str)   { return assign(str, strLength(str)); }
     Zbase& operator=(Char ch)           { return assign(&ch, 1); }
     Zbase& operator+=(const Zbase& str) { return append(str.c_str(), str.length()); }
@@ -573,11 +573,14 @@ template <class InputIterator> inline
 Zbase<Char, SP>& Zbase<Char, SP>::append(InputIterator first, InputIterator last)
 {
     const size_t len = std::distance(first, last);
-    const size_t thisLen = length();
-    reserve(thisLen + len); //make unshared and check capacity
-
-    *std::copy(first, last, rawStr_ + thisLen) = 0;
-    this->setLength(rawStr_, thisLen + len);
+	if (len > 0) //avoid making this string unshared for no reason
+	{
+		const size_t thisLen = length();
+		reserve(thisLen + len); //make unshared and check capacity
+
+		*std::copy(first, last, rawStr_ + thisLen) = 0;
+		this->setLength(rawStr_, thisLen + len);
+	}
     return *this;
 }