Snap for 5637134 from 1ab3b13ae5dfc07f1311a07d09e654b1cfc9c012 to qt-release

Change-Id: I318d9096e165a7b1b3f3bb2500365a2e923d5198
diff --git a/Parcel.cpp b/Parcel.cpp
index 4b61738..d6ea481 100644
--- a/Parcel.cpp
+++ b/Parcel.cpp
@@ -1324,8 +1324,8 @@
 
 const char* Parcel::readCString() const
 {
-    const size_t avail = mDataSize-mDataPos;
-    if (avail > 0) {
+    if (mDataPos < mDataSize) {
+        const size_t avail = mDataSize-mDataPos;
         const char* str = reinterpret_cast<const char*>(mData+mDataPos);
         // is the string's trailing NUL within the parcel's valid bounds?
         const char* eos = reinterpret_cast<const char*>(memchr(str, 0, avail));