Mid_FatFlushFile does not update the file information (file size) correctly

Mid_FatFlushFile does not update the file information correctly.

Mid_FatFlushFile() updates the physical file information but overwrites the cached file size by the previous parameter (size before the flush).

This results in the following behaviour:
A call to Mid_FatGetFileSize(), after writing to the file, returns the current file size (including cached data). A subsequent call to Mid_FatFlushFile() updates the physical file information and resets the cached file size to the previous physical size (size before the flush). So the next call of Mid_FatGetFileSize() returns an incorrect size but the physical filesystem is consistent.
A second call to Mid_FatFlushFile() then again exchanges the file size information. A call to Mid_FatGetFileSize() returns the correct size but the physical filesystem information keeps the size before the write.
NOTE: Mid_FatCloseFile() and Mid_FatReadFile() may also internally call Mid_FatFlushFile().