1.1 --- a/public/amtl/am-string.h	Fri Aug 23 22:29:44 2013 -0700
     1.2 +++ b/public/amtl/am-string.h	Sat Aug 24 01:29:03 2013 -0700
     1.3 @@ -51,18 +51,32 @@
     1.4      set(str, length);
     1.5    }
     1.6    AString(const AString &other) {
     1.7 -    set(other.chars_, other.length_);
     1.8 +    if (other.length_)
     1.9 +      set(other.chars_, other.length_);
    1.10    }
    1.11  
    1.12    AString &operator =(const char *str) {
    1.13 -    set(str, strlen(str));
    1.14 +    if (str && str[0]) {
    1.15 +      set(str, strlen(str));
    1.16 +    } else {
    1.17 +      chars_ = NULL;
    1.18 +      length_ = 0;
    1.19 +    }
    1.20      return *this;
    1.21    }
    1.22    AString &operator =(const AString &other) {
    1.23 -    set(other.chars_, other.length_);
    1.24 +    if (other.length_) {
    1.25 +      set(other.chars_, other.length_);
    1.26 +    } else {
    1.27 +      chars_ = NULL;
    1.28 +      length_ = 0;
    1.29 +    }
    1.30      return *this;
    1.31    }
    1.32  
    1.33 +  int compare(const AString &other) const {
    1.34 +    return strcmp(chars(), other.chars());
    1.35 +  }
    1.36    bool operator ==(const AString &other) const {
    1.37      return other.length() == length() &&
    1.38             memcmp(other.chars(), chars(), length()) == 0;