Bug 564980. Use JSString::length directly instead of JS_GetStringLength in some places in xpconnect. r=mrbkap

js/src/xpconnect/src/xpcprivate.h

@@ -907,8 +907,8 @@ public:
     { SetIsVoid(PR_TRUE); }
 
     explicit XPCReadableJSStringWrapper(JSString *str) :
-        nsDependentString((const PRUnichar *)::JS_GetStringChars(str),
-                          ::JS_GetStringLength(str))
+        nsDependentString(reinterpret_cast<const PRUnichar *>(::JS_GetStringChars(str)),
+                          str->length())
     { }
 };
 

js/src/xpconnect/src/xpcquickstubs.cpp

@@ -723,8 +723,9 @@ xpc_qsDOMString::xpc_qsDOMString(JSContext *cx, jsval v, jsval *pval,
         *pval = STRING_TO_JSVAL(s);  // Root the new string.
     }
 
-    len = JS_GetStringLength(s);
-    chars = (len == 0 ? traits::sEmptyBuffer : (const PRUnichar*)JS_GetStringChars(s));
+    len = s->length();
+    chars = (len == 0 ? traits::sEmptyBuffer :
+                        reinterpret_cast<const PRUnichar*>(JS_GetStringChars(s)));
     new(mBuf) implementation_type(chars, len);
     mValid = JS_TRUE;
 }
@@ -757,7 +758,7 @@ xpc_qsACString::xpc_qsACString(JSContext *cx, jsval v, jsval *pval)
     }
 
     const char *bytes = JS_GetStringBytes(s);
-    size_t len = JS_GetStringLength(s);
+    size_t len = s->length();
     new(mBuf) implementation_type(bytes, len);
     mValid = JS_TRUE;
 }
@@ -1041,6 +1042,7 @@ xpc_qsJsvalToWcharStr(JSContext *cx, jsval v, jsval *pval, PRUnichar **pstr)
         *pval = STRING_TO_JSVAL(str);  // Root the new string.
     }
 
+    // XXXbz this is casting away constness too...  That seems like a bad idea.
     *pstr = (PRUnichar*)JS_GetStringChars(str);
     return JS_TRUE;
 }