Backed out 2 changesets (bug 1353593) for windows build bustage a=backout

Backed out changeset c16b53fc17d9 (bug 1353593)
Backed out changeset 4bc441fc5860 (bug 1353593)

MozReview-Commit-ID: F2pCPyEOmwn

mfbt/Char16.h

@@ -56,12 +56,6 @@ public:
   {
     return reinterpret_cast<const wchar_t*>(mPtr);
   }
-
-  operator wchar_t*()
-  {
-    return const_cast<wchar_t*>(reinterpret_cast<const wchar_t*>(mPtr));
-  }
-
   operator const void*() const
   {
     return mPtr;

widget/windows/IMMHandler.cpp

@@ -344,7 +344,7 @@ IMMHandler::InitKeyboardLayout(nsWindow* aWindow,
     // Add room for the terminating null character
     sIMEName.SetLength(++IMENameLength);
     IMENameLength =
-      ::ImmGetDescriptionW(aKeyboardLayout, sIMEName.get(),
+      ::ImmGetDescriptionW(aKeyboardLayout, wwc(sIMEName.BeginWriting()),
                            IMENameLength);
     // Adjust the length to ignore the terminating null character
     sIMEName.SetLength(IMENameLength);

xpcom/base/nsSystemInfo.cpp

@@ -229,7 +229,7 @@ nsresult GetCountryCode(nsAString& aCountryCode)
   }
   // Now get the string for real
   aCountryCode.SetLength(numChars);
-  numChars = GetGeoInfoW(geoid, GEO_ISO2, char16ptr_t(aCountryCode.BeginWriting()),
+  numChars = GetGeoInfoW(geoid, GEO_ISO2, wwc(aCountryCode.BeginWriting()),
                          aCountryCode.Length(), 0);
   if (!numChars) {
     return NS_ERROR_FAILURE;

xpcom/ds/nsWindowsRegKey.cpp

@@ -354,8 +354,11 @@ nsWindowsRegKey::ReadStringValue(const nsAString& aName, nsAString& aResult)
         return NS_ERROR_OUT_OF_MEMORY;
       }
 
+      nsAString::iterator begin;
+      expandedResult.BeginWriting(begin);
+
       resultLen = ExpandEnvironmentStringsW(flatSource.get(),
-                                            expandedResult.get(),
+                                            wwc(begin.get()),
                                             resultLen + 1);
       if (resultLen <= 0) {
         rv = ERROR_UNKNOWN_FEATURE;

xpcom/io/FileUtilsWin.cpp

@@ -61,7 +61,7 @@ HandleToFilename(HANDLE aHandle, const LARGE_INTEGER& aOffset,
   do {
     mappedFilename.SetLength(mappedFilename.Length() + MAX_PATH);
     len = GetMappedFileNameW(GetCurrentProcess(), view,
-                             mappedFilename.get(),
+                             wwc(mappedFilename.BeginWriting()),
                              mappedFilename.Length());
   } while (!len && GetLastError() == ERROR_INSUFFICIENT_BUFFER);
   if (!len) {

xpcom/io/nsLocalFileWin.cpp

@@ -995,7 +995,7 @@ nsLocalFile::ResolveShortcut()
     return NS_ERROR_OUT_OF_MEMORY;
   }
 
-  wchar_t* resolvedPath = mResolvedPath.get();
+  wchar_t* resolvedPath = wwc(mResolvedPath.BeginWriting());
 
   // resolve this shortcut
   nsresult rv = gResolver->Resolve(mWorkingPath.get(), resolvedPath);
@@ -1365,7 +1365,7 @@ nsLocalFile::Create(uint32_t aType, uint32_t aAttributes)
   // Skip the first 'X:\' for the first form, and skip the first full
   // '\\machine\volume\' segment for the second form.
 
-  wchar_t* path = char16ptr_t(mResolvedPath.BeginWriting());
+  wchar_t* path = wwc(mResolvedPath.BeginWriting());
 
   if (path[0] == L'\\' && path[1] == L'\\') {
     // dealing with a UNC path here; skip past '\\machine\'
@@ -3743,7 +3743,7 @@ nsDriveEnumerator::Init()
   if (!mDrives.SetLength(length + 1, fallible)) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
-  if (!GetLogicalDriveStringsW(length, mDrives.get())) {
+  if (!GetLogicalDriveStringsW(length, wwc(mDrives.BeginWriting()))) {
     return NS_ERROR_FAILURE;
   }
   mDrives.BeginReading(mStartOfCurrentDrive);

xpcom/io/nsNativeCharsetUtils.cpp

@@ -929,8 +929,12 @@ NS_CopyNativeToUnicode(const nsACString& aInput, nsAString& aOutput)
     return NS_ERROR_OUT_OF_MEMORY;
   }
   if (resultLen > 0) {
-    char16ptr_t result = aOutput.BeginWriting();
-    ::MultiByteToWideChar(CP_ACP, 0, buf, inputLen, result, resultLen);
+    nsAString::iterator out_iter;
+    aOutput.BeginWriting(out_iter);
+
+    char16_t* result = out_iter.get();
+
+    ::MultiByteToWideChar(CP_ACP, 0, buf, inputLen, wwc(result), resultLen);
   }
   return NS_OK;
 }
@@ -974,6 +978,41 @@ NS_CopyUnicodeToNative(const nsAString&  aInput, nsACString& aOutput)
   return NS_OK;
 }
 
+// moved from widget/windows/nsToolkit.cpp
+int32_t
+NS_ConvertAtoW(const char* aStrInA, int aBufferSize, char16_t* aStrOutW)
+{
+  return MultiByteToWideChar(CP_ACP, 0, aStrInA, -1, wwc(aStrOutW), aBufferSize);
+}
+
+int32_t
+NS_ConvertWtoA(const char16_t* aStrInW, int aBufferSizeOut,
+               char* aStrOutA, const char* aDefault)
+{
+  if ((!aStrInW) || (!aStrOutA) || (aBufferSizeOut <= 0)) {
+    return 0;
+  }
+
+  int numCharsConverted = WideCharToMultiByte(CP_ACP, 0, char16ptr_t(aStrInW), -1,
+                                              aStrOutA, aBufferSizeOut,
+                                              aDefault, nullptr);
+
+  if (!numCharsConverted) {
+    if (GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
+      // Overflow, add missing null termination but return 0
+      aStrOutA[aBufferSizeOut - 1] = '\0';
+    } else {
+      // Other error, clear string and return 0
+      aStrOutA[0] = '\0';
+    }
+  } else if (numCharsConverted < aBufferSizeOut) {
+    // Add 2nd null (really necessary?)
+    aStrOutA[numCharsConverted] = '\0';
+  }
+
+  return numCharsConverted;
+}
+
 #else
 
 #include "nsReadableUtils.h"

xpcom/string/nsString.h

@@ -148,6 +148,49 @@ private:
   NS_ConvertUTF8toUTF16(char16_t) = delete;
 };
 
+
+#ifdef MOZ_USE_CHAR16_WRAPPER
+
+inline char16_t*
+wwc(wchar_t* aStr)
+{
+  return reinterpret_cast<char16_t*>(aStr);
+}
+
+inline wchar_t*
+wwc(char16_t* aStr)
+{
+  return reinterpret_cast<wchar_t*>(aStr);
+}
+
+inline const char16_t*
+wwc(const wchar_t* aStr)
+{
+  return reinterpret_cast<const char16_t*>(aStr);
+}
+
+inline const wchar_t*
+wwc(const char16_t* aStr)
+{
+  return reinterpret_cast<const wchar_t*>(aStr);
+}
+
+#else
+
+inline char16_t*
+wwc(char16_t* aStr)
+{
+  return aStr;
+}
+
+inline const char16_t*
+wwc(const char16_t* aStr)
+{
+  return aStr;
+}
+
+#endif
+
 // the following are included/declared for backwards compatibility
 typedef nsAutoString nsVoidableString;