Require length in sk_wchar_to_string.

src/utils/win/SkDWrite.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkDWrite.h"
 #include "SkHRESULT.h"
 #include "SkOnce.h"
@@ skipping 49 matching lines @@
     }
     name->reset(wlen);
     wlen = MultiByteToWideChar(CP_UTF8, 0, skname, -1, name->get(), wlen);
     if (0 == wlen) {
         HRM(HRESULT_FROM_WIN32(GetLastError()), "Could not convert wchar to utf-8.");
     }
     return S_OK;
 }
 
 /** Converts a WCHAR string to a utf8 string. */
-HRESULT sk_wchar_to_skstring(WCHAR* name, SkString* skname) {
-    int len = WideCharToMultiByte(CP_UTF8, 0, name, -1, NULL, 0, NULL, NULL);
+HRESULT sk_wchar_to_skstring(WCHAR* name, int nameLen, SkString* skname) {
+    int len = WideCharToMultiByte(CP_UTF8, 0, name, nameLen, NULL, 0, NULL, NULL);
     if (0 == len) {
+        if (nameLen <= 0) {
+            skname->reset();
+            return S_OK;
+        }
         HRM(HRESULT_FROM_WIN32(GetLastError()),
             "Could not get length for utf-8 to wchar conversion.");
     }
-    skname->resize(len - 1);
+    skname->resize(len);
 
-    // TODO: remove after https://code.google.com/p/skia/issues/detail?id=1989 is fixed.
-    // If we resize to 0 then the skname points to gEmptyRec (the unique empty SkString::Rec).
-    // gEmptyRec is static const and on Windows this means the value is in a read only page.
-    // Writing to it in the following call to WideCharToMultiByte will cause an access violation.
-    if (1 == len) {
-        return S_OK;
-    }
-
-    len = WideCharToMultiByte(CP_UTF8, 0, name, -1, skname->writable_str(), len, NULL, NULL);
+    len = WideCharToMultiByte(CP_UTF8, 0, name, nameLen, skname->writable_str(), len, NULL, NULL);
     if (0 == len) {
         HRM(HRESULT_FROM_WIN32(GetLastError()), "Could not convert utf-8 to wchar.");
     }
     return S_OK;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Locale
 
 void sk_get_locale_string(IDWriteLocalizedStrings* names, const WCHAR* preferedLocale,
                           SkString* skname) {
     UINT32 nameIndex = 0;
     if (preferedLocale) {
         // Ignore any errors and continue with index 0 if there is a problem.
         BOOL nameExists;
         names->FindLocaleName(preferedLocale, &nameIndex, &nameExists);
         if (!nameExists) {
             nameIndex = 0;
         }
     }
 
-    UINT32 nameLength;
-    HRVM(names->GetStringLength(nameIndex, &nameLength), "Could not get name length.");
-    nameLength += 1;
+    UINT32 nameLen;
+    HRVM(names->GetStringLength(nameIndex, &nameLen), "Could not get name length.");
 
-    SkSMallocWCHAR name(nameLength);
-    HRVM(names->GetString(nameIndex, name.get(), nameLength), "Could not get string.");
+    SkSMallocWCHAR name(nameLen+1);
+    HRVM(names->GetString(nameIndex, name.get(), nameLen+1), "Could not get string.");
 
-    HRV(sk_wchar_to_skstring(name.get(), skname));
+    HRV(sk_wchar_to_skstring(name.get(), nameLen, skname));
 }
 
 HRESULT SkGetGetUserDefaultLocaleNameProc(SkGetUserDefaultLocaleNameProc* proc) {
     *proc = reinterpret_cast<SkGetUserDefaultLocaleNameProc>(
         GetProcAddress(LoadLibraryW(L"Kernel32.dll"), "GetUserDefaultLocaleName")
     );
     if (!*proc) {
         HRESULT hr = HRESULT_FROM_WIN32(GetLastError());
         if (!IS_ERROR(hr)) {
             hr = ERROR_PROC_NOT_FOUND;
         }
         return hr;
     }
     return S_OK;
 }