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