1	#### var ref to array 'preHooks[@]'
2	#
3	# This idiom discussed on
4	# https://github.com/NixOS/nixpkgs/pull/147629
5
6	shopt -s eval_unsafe_arith 2>/dev/null # required for OSH
7
8	show() {
9	echo show
10
11	# These are actually different
12	argv.py ${!hooksSlice}
13
14	argv.py ${!hooksSlice+"${!hooksSlice}"}
15	}
16
17	hooksSlice='preHooks[@]'
18
19	preHooks=()
20	show
21
22	preHooks=('foo bar' baz)
23	show
24
25	# WTF this exposes a difference? But not the test case below?
26
27	# What's happening here?
28	# Uncomment this and get an error in bash about hookSlice, even though we never
29	# undefined it.
30
31	#wtf=1
32	#
33	# line 6: !hooksSlice: unbound variable
34
35	if test -n "$wtf"; then
36	# 4.4.0(1)-release
37	# echo $BASH_VERSION
38
39	set -u
40	preHooks=()
41	show
42
43	preHooks=('foo bar' baz)
44	show
45	fi
46
47	## STDOUT:
48	show
49	[]
50	[]
51	show
52	['foo', 'bar', 'baz']
53	['foo bar', 'baz']
54	## END
55
56	#### Same as above with set -u
57	show() {
58	echo show
59
60	# These are actually different
61	argv.py ${!hooksSlice}
62
63	argv.py ${!hooksSlice+"${!hooksSlice}"}
64	}
65
66	hooksSlice='preHooks[@]'
67
68	set -u
69	preHooks=()
70	show
71
72	preHooks=('foo bar' baz)
73	show
74
75	## STDOUT:
76	show
77	## END
78	## status: 1
79
80
81	#### ${!ref} to undefined array
82
83	set -u
84	shopt -s eval_unsafe_arith || true 2>/dev/null
85
86	#preHooks=()
87	hookSlice="preHooks[@]"
88
89	argv.py ${!hookSlice+"${!hookSlice}"}
90
91	for element in ${!hookSlice+"${!hookSlice}"}; do
92	echo $element
93	done
94
95	## STDOUT:
96	[]
97	## END
98
99	#### ${!ref} to undefined string var is fatal, INCONSISTENT with array
100	hookSlice='preHooks'
101
102	argv.py ${!hookSlice}
103
104	set -u
105
106	argv.py ${!hookSlice}
107
108	echo end
109
110	## status: 1
111	## STDOUT:
112	[]
113	## END
114
115	#### export with dynamic var name +=
116
117	orig() {
118	export NIX_LDFLAGS${role_post}+=" -L$1/lib64"
119	}
120
121	new() {
122	local var_name="NIX_LDFLAGS$role_post"
123	local value=" -L$1/lib64"
124
125	eval "$var_name"+='$value'
126	export "$var_name"
127	}
128
129	role_post='_foo'
130
131	# set -u
132
133	if test -n "${BASH_VERSION:-}"; then
134	orig one
135	fi
136
137	declare -p NIX_LDFLAGS_foo # inspect it
138	unset NIX_LDFLAGS_foo
139
140	new one
141
142	declare -p NIX_LDFLAGS_foo # inspect it
143
144	## STDOUT:
145	declare -x NIX_LDFLAGS_foo=" -Lone/lib64"
146	declare -x NIX_LDFLAGS_foo=" -Lone/lib64"
147	## END
148	## OK osh STDOUT:
149	declare -x NIX_LDFLAGS_foo=' -Lone/lib64'
150	## END
151