LegacyUpdate/shared/HResult.c

#include "stdafx.h"
#include <windows.h>
#include "HResult.h"
#include "LegacyUpdate.h"
#include "VersionInfo.h"

static BOOL g_loadedHModule;
static HMODULE g_messagesHModule;

EXTERN_C LPWSTR GetMessageForHresult(HRESULT hr) {
	LPWSTR message = NULL;

	if (HRESULT_FACILITY(hr) == FACILITY_WINDOWSUPDATE) {
		if (!g_loadedHModule) {
			g_loadedHModule = TRUE;

			// Load messages table from main dll
			LPWSTR installPath;
			if (GetInstallPath(&installPath)) {
				WCHAR path[MAX_PATH];
				wsprintf(path, L"%ls\\LegacyUpdate.dll", installPath);
				g_messagesHModule = LoadLibrary(path);
				LocalFree(installPath);
			}

			if (!g_messagesHModule) {
				// Try the current module
				g_messagesHModule = (HMODULE)&__ImageBase;
			}
		}

		FormatMessage(FORMAT_MESSAGE_FROM_HMODULE | FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_IGNORE_INSERTS, g_messagesHModule, hr, LANG_NEUTRAL, (LPWSTR)&message, 0, NULL);
	}

	if (message == NULL && !FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, hr, LANG_NEUTRAL, (LPWSTR)&message, 0, NULL)) {
		message = (LPWSTR)LocalAlloc(LPTR, 17 * sizeof(WCHAR));
		wsprintf(message, L"Error 0x%08X", hr);
		return message;
	}

	// Truncate trailing \r\n if any
	int len = lstrlen(message);
	if (len >= 2 && message[len - 2] == '\r' && message[len - 1] == '\n') {
		message[len - 2] = 0;
	}

	// Remove title part in braces
	if (len > 1 && message[0] == '{') {
		LPWSTR closeBrace = wcsstr(message, L"}\r\n");
		if (closeBrace) {
			message = closeBrace + 3;
		}
	}

	return message;
}