lib/49469: libbz2 compress.c doesn't build, breaking netbsd build.

[vallesroc%gmail.com@localhost]

>Number:         49469
>Category:       lib
>Synopsis:       libbz2 compress.c doesn't build, breaking netbsd build.
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Dec 14 14:15:00 +0000 2014
>Originator:     Roc Vallès Domènech
>Release:        Current (20141214)
>Organization:
>Environment:
NetBSD yuukonet.hell 6.99.28 NetBSD 6.99.28 (YUUKONET) #7: Sat Jan 4 15:21:11 UTC 2014  rvalles%yuukonet.hell@localhost:/usr/src/sys/arch/i386/compile/YUUKONET i386
>Description:
#   compile  libbz2/compress.o
/usr/src/../tools/bin/i486--netbsdelf-gcc -O2 -march=athlon-xp -mfpmath=sse -msse2 -
O3 -pipe   -std=gnu99    -Wall -Wstrict-prototypes -Wmissing-prototypes -Wpointer-ar
ith -Wno-sign-compare  -Wno-traditional  -Wa,--fatal-warnings -Wreturn-type -Wswitch
 -Wshadow -Wcast-qual -Wwrite-strings -Wextra -Wno-unused-parameter -Wno-sign-compar
e -Wold-style-definition -Wsign-compare -Wformat=2  -Wno-format-zero-length  -Werror
   -fstack-protector -Wstack-protector   --param ssp-buffer-size=1   --sysroot=/usr/
src/../obj/destdir.i386  -D_FORTIFY_SOURCE=2 -c    /usr/src/external/bsd/bzip2/dist/
compress.c -o compress.o
/usr/src/external/bsd/bzip2/dist/compress.c: In function 'BZ2_compressBlock':
/usr/src/external/bsd/bzip2/dist/compress.c:403:25: error: 'cost[5]' may be used uni
nitialized in this function [-Werror=maybe-uninitialized]
             if (cost[t] < bc) { bc = cost[t]; bt = t; };

For what's worth, it was initialized like this:
         for (t = 0; t < nGroups; t++) cost[t] = 0;

Just a few lines above. Just gcc being weird.
>How-To-Repeat:
Get current sources.

Try to build them (x86, 32bit): (/usr/src) ./build.sh -O ../obj -T ../tools -U distribution
>Fix: