iostream bug in g++ 2.95

[Dave Gomboc <dave at cs dot ualberta dot ca>]

Using gcc 2.95.1, redhat linux 6.0 on dual PII.

Bug report: c++ istream's getline reads more characters than it should...
according to The C++ Programming Language, 3rd edition (seventh printing),
by Bjarne Stroustrup, anyway.  Expected behavior is to be able to read the
double and int from the first line of (the piped-in) test.input, after
reading off the name.  What happens is the name gets read correctly, but
the double and the int are barfo.  I think the reason is that the stream's
failbit is getting set: C++PL doesn't say that it should be set.  Of
course, it's not the ISO C++ standard, but I don't have a copy of that to
reference.

The attached tar.gz includes

  test.cpp   -- source file
  test.input -- some sample data to pipe into the program when you run it
  test.ii
  test.s     -- these two generated by the command line

g++ -v --save-temps -Wall test.cpp

which gave the following output as it proceeded:

(I typed the below in manually, so there may be a typo or two)

Reading specs from /usr/opt/gcc/lib/gcc-lib/i686-pc-linux-gnu/2.95.1/specs
gcc version 2.95.1 19990816 (release)
 /usr/opt/gcc/lib/gcc-lib/i686-pc-linux-gnu/2.95.1/cpp -lang-c++ -v
-D__GNUC__=2 -D__GNUG__=2 -D__GNUC_MINOR__=95 -D__cplusplus -D__ELF__
-Dunix -D__i386__ -Dlinux -D__ELF__ -D__unix__ -D__i386__ -D__linux__
-D__unix -D__linux -Asystem(posix) -D__EXCEPTIONS -Wall -Acpu(i386)
-Amachine(i386) -Di386 -D__i386 -D__i386__ -Dpentiumpro -D__i686
-D__i686__ -D__pentiumpeo -D__pentiumpro__ test.cpp test.ii
GNU CPP version 2.95.1 19990816 (release) (i386 Linux/ELF)
#include "..." search starts here:
#include <...> search starts here:
 /usr/opt/gcc/lib/gcc-lib/i686-pc-linux-gnu/2.95.1/include/g++
 /usr/local/include
/usr/opt/gcc/lib/gcc-lib/i686-pc-linux-gnu/2.95.1/../../../../i686-pc-linux-gnu/include
 /usr/opt/gcc/lib/gcc-lib/i686-pc-linux-gnu/2.95.1/include
 /usr/include
End of search list.
The following default directories have been omitted from the search path:
End of omitted list.
 /usr/opt/gcc/lib/gcc-lib/i686-pc-linux-gnu/2.95.1/cc1plus test.ii -quiet
-dumpbase test.cc -Wall -version -o test.s
GNU C++ version 2.95.1 19990816 (release) (i686-pc-linux-gnu) compiled by
GNU C version 2.95.1 19990816 (release).
 as -V -Qy -o test.o test.s
GNU assembler version 2.9.1 (i386-redhat-linux), using BFD version 2.9.1.0.23
 /usr/opt/gcc/lib/gcc-lib/i686-pc-linux-gnu/2.95.1/collect2 -m elf_i386
-dynamic-linker /lib/ld-linux.so.2 /usr/lib/crt1.o /usr/lib/crti.o
/usr/opt/gcc/lib/gcc-lib/i686-pc-linux-gnu/2.95.1/crtbegin.o
-L/usr/opt/gcc/lib/gcc-lib/i686-pc-linux/gnu/2.95.1 -L/usr/opt/gcc/lib
test.o -lstdc++ -lm -lgcc -lc -lgcc
/usr/opt/gcc/lib/gcc-lib/i686-pc-linux-gnu/2.95.1/crtend.o /usr/lib/crtn.o

(the formatting got a bit whacked by the mail message editor too)

Dave

--
Dave Gomboc				Graduate Student
Department of Computing Science		Phone: (780)907-3214
University of Alberta			Email: dave@cs.ualberta.ca

bug.tar.gz