libstdc++/6648: Problems with cin.getline (interactive)

[Peter Schmid <schmid at snake dot iap dot physik dot tu-darmstadt dot de>]

>Number:         6648
>Category:       libstdc++
>Synopsis:       Problems with cin.getline (interactive)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon May 13 08:46:00 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Peter Schmid
>Release:        3.1 20020505 (prerelease)
>Organization:
TU Darmstadt
>Environment:
System: Linux kiste 2.4.18 #8 Sat Mar 9 15:33:15 CET 2002 i686 unknown
Architecture: i686
binutils  20020428
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: ../gcc/configure --enable-shared --disable-nls --enable-threads=posix --enable-languages=c,c++,f77,objc
>Description:
There is a severe regression in readline when run
interactively. Consider the following test case tio.C. When run, I
have to type the return key twice on the keyboard for getline to finish. All
other libstdc++ implementations, I have access to, need only one return
key press.

>How-To-Repeat:
source code tio.C
#include <iostream>

#define BUFFSIZ		2048

int main()
{	using namespace std;
        char buff[BUFFSIZ];
	cout << "Enter file name of input file: ";
	cin.getline(buff, BUFFSIZ);					       
}

g++ -v -o tio tio.C -W -Wall -g
Reading specs from /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/specs
Configured with: ../gcc/configure --enable-shared --disable-nls --enable-threads=posix --enable-languages=c,c++,f77,objc
Thread model: posix
gcc version 3.1 20020505 (prerelease)
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/cc1plus -v -D__GNUC__=3 -D__GNUC_MINOR__=1 -D__GNUC_PATCHLEVEL__=0 -D__ELF__ -Dunix -D__gnu_linux__ -Dlinux -D__ELF__ -D__unix__ -D__gnu_linux__ -D__linux__ -D__unix -D__linux -Asystem=posix -D__NO_INLINE__ -D__STDC_HOSTED__=1 -D_GNU_SOURCE -Acpu=i386 -Amachine=i386 -Di386 -D__i386 -D__i386__ -D__tune_i686__ -D__tune_pentiumpro__ tio.C -D__GNUG__=3 -D__DEPRECATED -D__EXCEPTIONS -D__GXX_ABI_VERSION=100 -quiet -dumpbase tio.C -g -W -Wall -version -o /tmp/ccHeXvC5.s
GNU CPP version 3.1 20020505 (prerelease) (cpplib) (i386 Linux/ELF)
GNU C++ version 3.1 20020505 (prerelease) (i686-pc-linux-gnu)
	compiled by GNU C version 3.1 20020505 (prerelease).
ignoring nonexistent directory "NONE/include"
ignoring nonexistent directory "/usr/local/i686-pc-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include/g++-v3
 /usr/local/include/g++-v3/i686-pc-linux-gnu
 /usr/local/include/g++-v3/backward
 /usr/local/include
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/include
 /usr/include
End of search list.
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/../../../../i686-pc-linux-gnu/bin/as -V -Qy -o /tmp/ccuPbK8I.o /tmp/ccHeXvC5.s
GNU assembler version 020428 (i686-pc-linux-gnu) using BFD version 020428 20020428
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/collect2 --eh-frame-hdr -m elf_i386 -dynamic-linker /lib/ld-linux.so.2 -o tio /usr/lib/crt1.o /usr/lib/crti.o /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/crtbegin.o -L/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1 -L/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/../../../../i686-pc-linux-gnu/lib -L/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/../../.. /tmp/ccuPbK8I.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/crtend.o /usr/lib/crtn.o

./tio
Enter file name of input file: hallo [first return]
[second return]

>Fix:
	
>Release-Note:
>Audit-Trail:
>Unformatted: