Assertion failure reading a single character from stdin

[rgrjr]

The code below used to work for reading a single character, at least as recently as r45000, but fails miserably in r49633. TIA,

rogers@rgr> cat new-test.pir

.sub test :main
	.local pmc stdin
	stdin = getstdin
	.local string input_string
	.local int len
	input_string = stdin.'read'(1)
	len = length input_string
	print "got len "
	print len
	print "\n"
.end
rogers@rgr> ./parrot new-test.pir
src/gc/string_gc.c:442: failed assertion '!(*Buffer_bufflagsptr(str) & Buffer_shared_FLAG)'
Backtrace - Obtained 21 stack frames (max trace depth is 32).
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0x75a42) [0xb754ea42]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(Parrot_confess+0x9a) [0xb754ea0a]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0x88568) [0xb7561568]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0x846d8) [0xb755d6d8]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0x7ee65) [0xb7557e65]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0xe8b99) [0xb75c1b99]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0xe80d0) [0xb75c10d0]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0xe671c) [0xb75bf71c]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(Parrot_io_reads+0x20a) [0xb75bd48a]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0x158fb9) [0xb7631fb9]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0x168eaf) [0xb7641eaf]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0x45622) [0xb751e622]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0xd1e31) [0xb75aae31]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0xd0eaa) [0xb75a9eaa]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(+0x950ff) [0xb756e0ff]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(Parrot_pcc_invoke_from_sig_object+0x19b) [0xb756873b]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(Parrot_ext_call+0x103) [0xb754f603]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(Parrot_runcode+0x1af) [0xb754c49f]
/alt/usr/src/parrot/blib/lib/libparrot.so.2.9.1(imcc_run_pbc+0x99) [0xb768d719]
./parrot() [0x8049085]
/lib/libc.so.6(__libc_start_main+0xfe) [0xb726ec0e]
Aborted
rogers@rgr> 

[rgrjr]

Binary search shows that this has failed ever since r46353, when the assertion was added, so this is probably something that was missed when immutable strings were implemented.

[nwellnhof]

I think it's perfectly safe to reallocate shared strings, so the assertion should be removed.

Nick

[rgrjr]

I tried removing the assertions, but got a zero-length string, which I suppose is a new bug. (In r46352, it got a string consisting of a single null character, which is wrong in yet another way.)

[nwellnhof]

This should also be fixed by r49646.