Avoid \] in BREs and EREs

* bootstrap (PACKAGE_NAME, PACKAGE_BUGREPORT):
* lib/autoconf/status.m4 (AC_OUTPUT_MAKE_DEFS):
* maint.mk (longopt_re, gpg_key_ID):
* tests/m4sugar.at (m4_dumpdef):
Avoid \] in POSIX-specified regular expressions, as POSIX says \]
produces undefined results in BREs and EREs.

bootstrap

@@ -149,9 +149,9 @@ VERSION=$(build-aux/git-version-gen .tarball-version)
 # get copied into the generated configure script, so we need to get them
 # right.  Caution: there is a hard tab in one of the regexes below.
 PACKAGE_NAME=$(sed -n < configure.ac \
-   -e 's/^m4_define(\[autoconf_PACKAGE_NAME\], \[\([^]]*\)\])$/\1/p')
+   -e 's/^m4_define(\[autoconf_PACKAGE_NAME], \[\([^]]*\)])$/\1/p')
 PACKAGE_BUGREPORT=$(sed -n < configure.ac \
-   -e 's/^m4_define(\[autoconf_PACKAGE_BUGREPORT\], \[\([^]]*\)\])$/\1/p')
+   -e 's/^m4_define(\[autoconf_PACKAGE_BUGREPORT], \[\([^]]*\)])$/\1/p')
 
 if [ -z "$RELEASE_YEAR" ]; then
     echo "$me: error: could not extract RELEASE_YEAR from configure.ac" >&2

lib/autoconf/status.m4

@@ -1772,9 +1772,7 @@ s/^[	 ]*#[	 ]*define[	 ][	 ]*\([^	 ][^	 ]*\)[	 ]*\(.*\)/-D\1=\2/g
 t quote
 b any
 :quote
-s/[	 `~#$^&*(){}\\|;'\''"<>?]/\\&/g
-s/\[/\\&/g
-s/\]/\\&/g
+s/[][	 `~#$^&*(){}\\|;'\''"<>?]/\\&/g
 s/\$/$$/g
 H
 :any

maint.mk

@@ -826,7 +826,7 @@ sc_trailing_blank:
 # Match lines like the following, but where there is only one space
 # between the options and the description:
 #   -D, --all-repeated[=delimit-method]  print all duplicate lines\n
-longopt_re = --[a-z][0-9A-Za-z-]*(\[?=[0-9A-Za-z-]*\]?)?
+longopt_re = --[a-z][0-9A-Za-z-]*(\[?=[0-9A-Za-z-]*]?)?
 sc_two_space_separator_in_usage:
 	@prohibit='^   *(-[A-Za-z],)? $(longopt_re) [^ ].*\\$$'		\
 	halt='help2man requires at least two spaces between an option and its description'\
@@ -1393,7 +1393,7 @@ gpg_key_ID ?=								\
   $$(cd $(srcdir)							\
      && git cat-file tag v$(VERSION)					\
         | $(gpgv) --status-fd 1 --keyring /dev/null - - 2>/dev/null	\
-        | $(AWK) '/^\[GNUPG:\] ERRSIG / {print $$3; exit}')
+        | $(AWK) '/^\[GNUPG:] ERRSIG / {print $$3; exit}')
 
 translation_project_ ?= coordinator@translationproject.org
 

tests/m4sugar.at

@@ -196,7 +196,7 @@ m4_dumpdef([good], [oops])
 ]])
 
 AT_CHECK_M4SUGAR([-o-], 1, [], [stderr])
-AT_CHECK([grep '^good:	\[[yep\]]$' stderr], [0], [ignore])
+AT_CHECK([grep '^good:	\[[yep]]$' stderr], [0], [ignore])
 AT_CHECK([grep 'm4@&t@_dumpdef: undefined.*oops' stderr], [0], [ignore])
 
 # Check that pushdef stacks can be dumped.