Fix starting position of file offset when the file is shorter than 1024 bytes.  Simplify searching, and make sure we get the last EOF marker in the file by searching from the end of the data range.
Fix starting position of file offset when the file is shorter than 1024 bytes.  Simplify searching, and make sure we get the last EOF marker in the file by searching from the end of the data range.

JackieXie168/skim,JackieXie168/skim,JackieXie168/skim,JackieXie168/skim,JackieXie168/skim