[Mingw-notify] [ mingw-Bugs-848480 ] tellg/seekg bug with DOS text files

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Bugs item #848480, was opened at 2003-11-24 13:36
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Category: gcc
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: Stuart Mentzer (stuart_mentzer)
Assigned to: Danny Smith (dannysmith)
Summary: tellg/seekg bug with DOS text files

Initial Comment:
Using tellg/seekg to backup by one line in some DOS text 
files is going to the wrong location now both with MinGW 
GCC 3.2.3 and Cygwin GCC 3.3.1.  Using seekg with a 
tellg value doesn't return to the correct point in the file.  
It works properly with *nix text files (\n line endings).

Other users have tried the example on non-MinGW GCCs 
and report that it works correctly for DOS and *nix text 
files so I believe this is a bug in the MinGW port.

--
Stuart



// seek.cc
//
// Build with g++ seek.cc -o seek.exe 

#include <string>
#include <iostream>
#include <fstream>


int
main()
{
   std::ifstream afile( "sample.txt" );
   std::string inp_line;
   getline( afile, inp_line );
   std::cout << inp_line << std::endl;
   std::streampos sp = afile.tellg(); // Start of 2nd line
   getline( afile, inp_line );
   std::cout << inp_line << std::endl;
   getline( afile, inp_line );
   std::cout << inp_line << std::endl;
   afile.seekg( sp ); // Return to start of 2nd line
   getline( afile, inp_line );
   std::cout << inp_line << std::endl;
   afile.close();
   return 0;
}


/* sample.txt File (DOS line endings)

first line
second line
third line
fourth line

*/


/* Output generated by MinGW GCC 3.2.3 or Cygwin 
GCC 3.3.1

first line
second line
third line
nd line

*/

Additional Information:

Platform: Windows 2000 SP2

g++ -v
Reading specs from E:/mingw/bin/../lib/gcc-
lib/mingw32/3.2.3/specs
Configured with: ../gcc/configure --with-gcc --with-gnu-
ld --with-gnu-as --host=mingw32 --target=mingw32 --
prefix=/mingw --enable-th
reads --disable-nls --enable-languages=c++,f77,objc --
disable-win32-registry --disable-shared --enable-sjlj-
exceptions
Thread model: win32
gcc version 3.2.3 (mingw special 20030504-1)

ld -v
GNU ld version 2.13.90 20030111

MinGW installation from separate components

Tested in Windows console environment

#define __MINGW32_VERSION 3.2

win32api version 2.4

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