1# $NetBSD: job-output-null.mk,v 1.4 2022/09/03 08:03:27 rillig Exp $
2#
3# Test how null bytes in the output of a command are handled.  Make processes
4# them using null-terminated strings, which may cut off some of the output.
5#
6# Before job.c 1.454 from 2022-09-03, make handled null bytes in the output
7# from the child process inconsistently.  It's an edge case though since
8# typically the child processes output text.
9
10# Note: The printf commands used in this test must only use a single format
11# string, without parameters.  This is because it is implementation-dependent
12# how many times the command 'printf "fmt%s" "" "" ""' calls write(2).
13#
14#         NetBSD /bin/sh                1 x write("fmtfmtfmt")
15#         Dash                          1 x write("fmtfmtfmt")
16#         NetBSD /bin/ksh               3 x write("fmt") (via /bin/printf)
17#         Bash 5                        3 x write("fmt")
18#
19# In the latter case the output may arrive in 1 to 3 parts, depending on the
20# exact timing, which in this test makes a crucial difference since before
21# job.c 1.454 from 2022-09-03, the outcome of the test depended on whether
22# there was a '\n' in each of the blocks from the output.  Depending on the
23# exact timing, the output of that test varied, its possible values were '2a',
24# '2a 2b', '2a 2c', '2a 2b 2c'.
25
26.MAKEFLAGS: -j1               # force jobs mode
27
28all: .PHONY
29          # The null byte from the command output is replaced with a single
30          # space by CollectOutput.
31          @printf '1\0trailing\n'
32          # expect: 1 trailing
33
34          # Give the parent process a chance to see the above output, but not
35          # yet the output from the next printf command.
36          @sleep 1
37
38          # Each null byte from the command output is replaced with a single
39          # space.
40          @printf '2a\0trailing\n''2b\0trailing\n''2c\0trailing\n'
41          # expect: 2a trailing
42          # expect: 2b trailing
43          # expect: 2c trailing
44
45          @sleep 1
46
47          # Each null byte from the command output is replaced with a single
48          # space.  Because there is no trailing newline in the output, these
49          # null bytes were replaced with spaces even before job.c 1.454 from
50          # 2022-09-03, unlike in the cases above.
51          #
52          # The three null bytes in a row test whether this output is
53          # compressed to a single space like in DebugFailedTarget.  It isn't.
54          @printf '3a\0without\0\0\0newline, 3b\0without\0\0\0newline.'
55          # expect: 3a without   newline, 3b without   newline.
56