From 7e515479b0e1156d9bae3fd2b5aab17f1aaa65be Mon Sep 17 00:00:00 2001
From: Sergei Dryganets <dryganets@users.noreply.github.com>
Date: Thu, 10 Aug 2017 03:09:46 -0700
Subject: [PATCH] LocalString doesn't have a check for nullptr

Summary:
LocalString doesn't have a check for null ptr which causes a crash if the null string passed.
Closes https://github.com/facebook/react-native/pull/15372

Differential Revision: D5601469

Pulled By: javache

fbshipit-source-id: a1b20efbae90009f0d465c077e6401a701d7515f
---
 .../jni/first-party/fb/jni/LocalString.cpp    | 22 ++++++++++---------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/ReactAndroid/src/main/jni/first-party/fb/jni/LocalString.cpp b/ReactAndroid/src/main/jni/first-party/fb/jni/LocalString.cpp
index 6827ec282d1..7e60d264230 100644
--- a/ReactAndroid/src/main/jni/first-party/fb/jni/LocalString.cpp
+++ b/ReactAndroid/src/main/jni/first-party/fb/jni/LocalString.cpp
@@ -82,16 +82,18 @@ size_t modifiedLength(const uint8_t* str, size_t* length) {
   // NUL-terminated: Scan for length and supplementary characters
   size_t i = 0;
   size_t j = 0;
-  while (str[i] != 0) {
-    if (str[i + 1] == 0 ||
-        str[i + 2] == 0 ||
-        str[i + 3] == 0 ||
-        !isFourByteUTF8Encoding(&(str[i]))) {
-      i += 1;
-      j += 1;
-    } else {
-      i += 4;
-      j += 6;
+  if (str != nullptr) {
+    while (str[i] != 0) {
+      if (str[i + 1] == 0 ||
+          str[i + 2] == 0 ||
+          str[i + 3] == 0 ||
+          !isFourByteUTF8Encoding(&(str[i]))) {
+        i += 1;
+        j += 1;
+      } else {
+        i += 4;
+        j += 6;
+      }
     }
   }