"scratch" file bug in g77/egcs1.1b

[Mako Sasaki]

I found that file I/O operations for I/O units opened as STATUS='SCRATCH' and FORM='FORMATTED' do not work correctly in g77/egcs1.1b;

* ==== Example ========================================
      character*32 ll
      open(10,form='formatted',status='scratch')
cccc  open(10,form='formatted')

* --------------- write 10 lines first --------
      do i=1,10
         write(10,'("first ",i3)') i
      end do  
      rewind 10

* --------------- write 5 lines after rewind --------
      do i=1,5
         write(10,'("second ",i3)') i
      end do  
      rewind 10

* --------------- read lines until EOF ....
      do i=1,1000
         read(10,end=150,fmt='(a)') ll
         write(*,*) ll
      end do  
  150 continue
      end
*============================================================

This program outputs the following lines when compiled with g77/egcs1.1b.

 second   1                      
 second   2                      
 second   3                      
 second   4                      
 second   5                      
    6                            
 first   7                       
 first   8                       
 first   9                       
 first  10

And expected output is only;

 second   1                      
 second   2                      
 second   3                      
 second   4                      
 second   5

It seems that "REWIND" operation does not put EOF, and garbage from the first write/rewind cycle remains.

When compiled with g77/egcs1.0.3a, it works correctly.

Binary "scratch" files and formatted files not opened as "scratch" do not have such a problem.

 ===================================================================
 Makoto Sasaki  : The Japan Research Institute Ltd.
                  sasaki@tyo.sci.jri.co.jp