From: Michal Privoznik <[email protected]>
As mentioned in the previous commit, the following function
doesn't echo '1' but '0':
func() {
local var=$(false)
echo $?
}
It's explained here [1]. Since this kind of error is not easy to
catch a new syntax-check rule is introduced. To avoid having
multiline grep and match only those patterns where '$?' is
examined, let's keep the rule simple and forbid all local
declarations with subshell.
1: https://www.shellcheck.net/wiki/SC2155
Signed-off-by: Michal Privoznik <[email protected]>
---
build-aux/syntax-check.mk | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/build-aux/syntax-check.mk b/build-aux/syntax-check.mk
index f605c9b0e3..ff44dfa2fe 100644
--- a/build-aux/syntax-check.mk
+++ b/build-aux/syntax-check.mk
@@ -394,6 +394,12 @@ sc_prohibit_g_autofree_const:
halt='‘g_autofree’ discards ‘const’ qualifier from pointer target type'
\
$(_sc_search_regexp)
+sc_prohibit_local_with_subshell:
+ @prohibit='local [a-zA-Z]+="?\$$\(.+' \
+ in_vc_files='\.sh(\.in)?$$' \
+ halt='local variable with subshell does not do what you think it does' \
+ $(_sc_search_regexp)
+
# Many of the function names below came from this filter:
# git grep -B2 '\<_('|grep -E '\.c- *[[:alpha:]_][[:alnum:]_]* ?\(.*[,;]$' \
--
2.52.0
