Test for 'errorformat'.  This will fail if the quickfix feature was disabled.

STARTTEST
:so small.vim
:" Also test a BOM is ignored.
:so mbyte.vim
:set encoding=utf-8
:7/start of errorfile/,/end of errorfile/w! Xerrorfile1
:7/start of errorfile/,/end of errorfile/-1w! Xerrorfile2
:/start of testfile/,/end of testfile/w! Xtestfile
:cf Xerrorfile2
:clast
:copen
:let a=w:quickfix_title
:wincmd p
gR=a

:cf Xerrorfile1
rA
:cn
rB
:cn
rC
:cn
rD
:cn
rE
:cn
:wincmd w
:let a=w:quickfix_title
:wincmd p
gR=a

:w! test.out             " Write contents of this file
:qa!
ENDTEST

start of errorfile
"Xtestfile", line 4.12: 1506-045 (S) Undeclared identifier fd_set.
"Xtestfile", line 7 col 19; this is an error
gcc -c -DHAVE_CONFIsing-prototypes -I/usr/X11R6/include  version.c
Xtestfile:13: parse error before `asd'
make: *** [vim] Error 1
in file "Xtestfile" linenr 16: there is an error

2 returned
"Xtestfile", linenr 19: yet another problem

Does anyone know what is the problem and how to correction it?
"Xtestfile", line 21 col 9: What is the title of the quickfix window?
"Xtestfile", line 22 col 9: What is the title of the quickfix window?
end of errorfile

start of testfile
line 2  xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 3  xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 4  xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 5  xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 6  xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 7  xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 8  xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 9  xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 10 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 11 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 12 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 13 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 14 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 15 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 16 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 17 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 18 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 19 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 20 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 21 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line 22 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
end of testfile