Fix regression in CursorWindow.copyStingToBuffer.

Bug: 5332296

Change-Id: Iff9eed786f0a8293b6156f883a66a322ddad5e99

Author: Jeff Brown

core/jni/android_database_CursorWindow.cpp

@@ -267,7 +267,7 @@ static void fillCharArrayBufferUTF(JNIEnv* env, jobject bufferObj,
     if (dataObj) {
         if (size) {
             jchar* data = static_cast<jchar*>(env->GetPrimitiveArrayCritical(dataObj, NULL));
-            utf8_to_utf16(reinterpret_cast<const uint8_t*>(str), len,
+            utf8_to_utf16_no_null_terminator(reinterpret_cast<const uint8_t*>(str), len,
                     reinterpret_cast<char16_t*>(data));
             env->ReleasePrimitiveArrayCritical(dataObj, data, 0);
         }

include/utils/Unicode.h

@@ -149,6 +149,13 @@ void utf8_to_utf32(const char* src, size_t src_len, char32_t* dst);
  */
 ssize_t utf8_to_utf16_length(const uint8_t* src, size_t srcLen);
 
+/**
+ * Convert UTF-8 to UTF-16 including surrogate pairs.
+ * Returns a pointer to the end of the string (where a null terminator might go
+ * if you wanted to add one).
+ */
+char16_t* utf8_to_utf16_no_null_terminator(const uint8_t* src, size_t srcLen, char16_t* dst);
+
 /**
  * Convert UTF-8 to UTF-16 including surrogate pairs. The destination buffer
  * must be large enough to hold the result as measured by utf8_to_utf16_length

libs/utils/Unicode.cpp

@@ -542,11 +542,7 @@ ssize_t utf8_to_utf16_length(const uint8_t* u8str, size_t u8len)
     return u16measuredLen;
 }
 
-/**
- * Convert a UTF-8 string to UTF-16. The destination UTF-16 buffer must have
- * space for NULL at the end.
- */
-void utf8_to_utf16(const uint8_t* u8str, size_t u8len, char16_t* u16str)
+char16_t* utf8_to_utf16_no_null_terminator(const uint8_t* u8str, size_t u8len, char16_t* u16str)
 {
     const uint8_t* const u8end = u8str + u8len;
     const uint8_t* u8cur = u8str;
@@ -569,7 +565,12 @@ void utf8_to_utf16(const uint8_t* u8str, size_t u8len, char16_t* u16str)
 
         u8cur += u8len;
     }
-    *u16cur = 0;
+    return u16cur;
+}
+
+void utf8_to_utf16(const uint8_t* u8str, size_t u8len, char16_t* u16str) {
+    char16_t* end = utf8_to_utf16_no_null_terminator(u8str, u8len, u16str);
+    *end = 0;
 }
 
 }