Bug 700498 - Change StringBuffer::append to take a JSLinearString*, not a JSAtom*. r=cdleary

js/src/jsstrinlines.h

@@ -77,7 +77,7 @@ class StringBuffer
     bool append(const jschar *chars, size_t len);
     bool append(const jschar *begin, const jschar *end);
     bool append(JSString *str);
-    bool append(JSAtom *atom);
+    bool append(JSLinearString *str);
     bool appendN(const jschar c, size_t n);
     bool appendInflated(const char *cstr, size_t len);
 
@@ -173,19 +173,14 @@ StringBuffer::append(JSString *str)
     JSLinearString *linear = str->ensureLinear(context());
     if (!linear)
         return false;
-    size_t strLen = linear->length();
-    if (!checkLength(cb.length() + strLen))
-        return false;
-    return cb.append(linear->chars(), strLen);
+    return append(linear);
 }
 
 inline bool
-StringBuffer::append(JSAtom *atom)
+StringBuffer::append(JSLinearString *str)
 {
-    size_t strLen = atom->length();
-    if (!checkLength(cb.length() + strLen))
-        return false;
-    return cb.append(atom->chars(), strLen);
+    JS::Anchor<JSString *> anch(str);
+    return cb.append(str->chars(), str->length());
 }
 
 inline bool