ReportError doesn't flush stderr before exiting, swallowing error output

[GoogleCodeExporter]

In gflags.cc:207's ReportError function exit(1) gets called without flushing 
stderr, so the error message doesn't necessarily get printed to the console. 
Needless to say, this is very annoying for your end users. :-)

Simple fix is to add this line after va_end(ap); :
fflush(stderr);

This is an issue under Cygwin's BASH, for example (although the cmd.exe prompt 
in Windows seems to output it OK).

Original issue reported on code.google.com by alastair.maw on 20 May 2011 at 1:20

[GoogleCodeExporter]

stderr is not buffered by default on any system that I know.  fflush(stderr) 
should be unnecessary.  Are you doing something unusual in your setup, perhaps? 
 Or does cygwin?  I don't see any mention of it on a quick web search.

Anyway, no harm in adding it, I suppose.  Feel free to draw up a patch.

Original comment by csilv...@gmail.com on 20 May 2011 at 6:15

[GoogleCodeExporter]

I've had a bit of a dig, and it turns out that the rxvt terminal emulator that 
ships with Cygwin buffers stderr. The reason for this seems to be that rxvt 
needs a pty I/O layer that simply doesn't exist on Windows, so it's emulated 
with pipes, which introduces the buffering. Given there's no harm adding it, 
I'll draw up a patch to work around this. Thanks.

Original comment by alastair.maw on 31 May 2011 at 9:34

[GoogleCodeExporter]

I just released a new version of gflags, and decided not to fix this for that.  
stderr is standardized to flush, and I think it's just confusing to add code to 
flush it anyway.  Presumably cygwin/rxvt users are used to dealing with 
problems of this sort?

You're right it's just one line of code, and easy to fix, so I can still be 
convinced to do it. :-)  I'm leaving the bug open.

Original comment by csilv...@gmail.com on 30 Jul 2011 at 2:50

[GoogleCodeExporter]

} stderr is standardized to flush, and I think it's just confusing to add code 
to flush it anyway.

Wouldn't it be clear enough if you simply comment the code properly?

// flush stderr before exiting as at least cygwin/rxvt buffers stderr
fflush (stderr);

This would make your library more reliable and such commented line of code 
couldn't be confusing to anyone who is digging into the code of it.

Original comment by andreas....@gmail.com on 11 Aug 2011 at 4:47

[GoogleCodeExporter]

OK, I'm convinced. :-)  It'll be in the next release.

Original comment by csilv...@gmail.com on 26 Aug 2011 at 12:00

• Changed state: Started

[GoogleCodeExporter]

This should be fixed in gflags 1.7, just released

Original comment by csilv...@gmail.com on 21 Dec 2011 at 4:26

• Changed state: Fixed