Fix StringView to properly convert NSStrings (#509)

NSStrings are utf16, so NSString::length returns the number of utf16
characters present in the string. When the string is entirely made up of
US-ASCII characters, everything's fine. But when characters requiring 16
bits are present, the size calculations were incorrect.

Fixed by calculating the length based on the destination character set
(i.e. UTF8).

1 files changed, 2 insertions, 1 deletions

diff --git a/Firestore/Source/Local/StringView.h b/Firestore/Source/Local/StringView.h
index 799baf8..b81b7b5 100644
--- a/Firestore/Source/Local/StringView.h
+++ b/Firestore/Source/Local/StringView.h
@@ -46,7 +46,8 @@ class StringView {
   // Creates a StringView from an NSString. When StringView is an argument type
   // into which an NSString* is passed, the caller should ensure that the
   // NSString is retained.
-  StringView(NSString *str) : data_([str UTF8String]), size_(str.length) {
+  StringView(NSString *str)
+      : data_([str UTF8String]), size_([str lengthOfBytesUsingEncoding:NSUTF8StringEncoding]) {
   }
 
   // Creates a StringView from the given char* pointer with an explicit size.