syncqt: Do not needlessly rewrite header files on Windows

SyncScanner::writeIfDifferent compares the size in the buffer with
the size of the existing file on disk to see whether the file should
be rewritten. However, on Windows the sizes hardly ever matched, because
the implicit \n to \r\n conversion only happened when writing the file
in text mode using ofstream. Take this into account.

Change-Id: Ic689390396fcc3a640640378743bd058f48a1779
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>

src/tools/syncqt/main.cpp

@@ -1534,8 +1534,14 @@ bool SyncScanner::writeIfDifferent(const std::string &outputFile, const std::str
     if (!std::filesystem::exists(outputDirectory))
         std::filesystem::create_directories(outputDirectory);
 
+    int expectedSize = buffer.size();
+#ifdef _WINDOWS
+    // File on disk has \r\n instead of just \n
+    expectedSize += std::count(buffer.begin(), buffer.end(), '\n');
+#endif
+
     if (std::filesystem::exists(outputFilePath)
-        && buffer.size() == std::filesystem::file_size(outputFilePath)) {
+        && expectedSize == std::filesystem::file_size(outputFilePath)) {
         char rdBuffer[bufferSize];
         memset(rdBuffer, 0, bufferSize);