Merge pull request #10984 from extrowerk:advanced_haiku_patches

* Haiku supporting patches

* Revert uneeded changes

* Whitespace cleanup

modules/core/src/utils/filesystem.cpp

@@ -34,7 +34,7 @@
 #include <errno.h>
 #include <io.h>
 #include <stdio.h>
-#elif defined __linux__ || defined __APPLE__
+#elif defined __linux__ || defined __APPLE__ || defined __HAIKU__
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
@@ -161,7 +161,7 @@ cv::String getcwd()
     sz = GetCurrentDirectoryA((DWORD)buf.size(), (char*)buf);
     return cv::String((char*)buf, (size_t)sz);
 #endif
-#elif defined __linux__ || defined __APPLE__
+#elif defined __linux__ || defined __APPLE__ || defined __HAIKU__
     for(;;)
     {
         char* p = ::getcwd((char*)buf, buf.size());
@@ -195,7 +195,7 @@ bool createDirectory(const cv::String& path)
 #else
     int result = _mkdir(path.c_str());
 #endif
-#elif defined __linux__ || defined __APPLE__
+#elif defined __linux__ || defined __APPLE__ || defined __HAIKU__
     int result = mkdir(path.c_str(), 0777);
 #else
     int result = -1;
@@ -310,7 +310,7 @@ private:
     Impl& operator=(const Impl&); // disabled
 };
 
-#elif defined __linux__ || defined __APPLE__
+#elif defined __linux__ || defined __APPLE__ || defined __HAIKU__
 
 struct FileLock::Impl
 {
@@ -424,7 +424,7 @@ cv::String getCacheDirectory(const char* sub_directory_name, const char* configu
             default_cache_path = "/tmp/";
             CV_LOG_WARNING(NULL, "Using world accessible cache directory. This may be not secure: " << default_cache_path);
         }
-#elif defined __linux__
+#elif defined __linux__ || defined __HAIKU__
         // https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
         if (default_cache_path.empty())
         {